E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)

[gslick]

Anyone have one of these? They look like nice supplies designed to replace the E3631A. Priced in the same range as the E3631A, so 2-3x of something like a Rigol DP832. But if you buy one now they'll throw in a  U1242C for free.

E36311A 80W Triple Output Power Supply, 6V, 5A & ±25V, 1A, USB only US$ 1,100
E36312A 80W Triple Output Power Supply, 6V, 5A & 2X 25V, 1A USB, LAN, (GPIB Opt) US$ 1,400
E36313A 160W Triple Output Power Supply, 6V, 10A & 2X 25V, 2A USB, LAN, (GPIB Opt) US$ 1,700
E36312A-GPB / E36313A-GPB GPIB interface module for E36312A, E36313A - installed US$ 150

In addition to lacking the LAN and optional GPIB interface, the E36311A also lacks the rear output and sense terminal connections, and also lacks the front panel USB connection for saving test setups, test results, screen images, and log data directly to the USB device plugged into the front panel.

E36300 Series Programmable DC Power Supplies Data Sheet
http://literature.cdn.keysight.com/litweb/pdf/5992-2124EN.pdf

Buy one through September 30, 2017 and get a free U1242C Handheld DMM
Buy Any Keysight Big5 Bench Instrument, Get A Complimentary Handheld!
http://literature.cdn.keysight.com/litweb/pdf/5992-2215EN.pdf

E36300 Triple Output Bench Power Supply Product Overview

[kilobyte]

Yes, they look really interesting.
I saw these new power supplies already some days before on the website from the German distributor Datatec.

According to a picture in the Service Manual they use a STM32F4. This explains the fast startup time of round about 5 seconds in the video from Keysight.
There is already a firmware update available on the website. No wonder to see a USB DFU Updater.
And after a quick look in the Firmware file I think I found some text that belongs to an easter egg

BR
Kai

[HighVoltage]

Looks really nice !

Especially to have Voltage, Current and Power finally on a Keysight PSU screen and that for all three channels in one view is great.

In Germany the list prices are:

E3611A:
Euro 989 +VAT

E3612A:
Euro 1258 +VAT

E3613A:
Euro 1528 +VAT

[rdl]

I don't see any need for the nursery school color coding. It looks out of place with the rest of the design and serves no purpose really, as everything appears to be arranged logically.

The front USB connector placement is a little odd (if that's what it is) seems like there's potential for blocking view of the display if something is plugged in it.

If you're going to use a green LED for power indicator at least use a modern true green type instead of that ugly snot green that's been around since the 80s, though almost anything is better than yet another blue LED.

[alm]

This explains the fast startup time of round about 5 seconds in the video from Keysight.

Five seconds startup is fast for a basic bench power supply? That is because the micros the days are much slower than the ones used in their previous supplies, right?

[nctnico]

I think I'll put a E36312A on my wish list! Pretty much what I have been looking for in a PSU and the small current + logging features seem very handy to me.

[colorado.rob]

The 12A and 13A seem to be the same size and features as the TTi MX100TP I just purchased, but with a lower load capability and at a higher price.  What am I missing?  The 11A is the same price, but far less capable.

[gslick]

E36300 Series Programmable DC Power Supplies User’s Guide
http://literature.cdn.keysight.com/litweb/pdf/E36311-90001.pdf

E36300 Series Programmable DC Power Supplies Programming Guide
http://literature.cdn.keysight.com/litweb/pdf/E36311-90008.pdf

E36300 Series Programmable DC Power Supplies Service Guide
http://literature.cdn.keysight.com/litweb/pdf/E36311-90009.pdf

Some images from the Service Guide:

[alm]

The 12A and 13A seem to be the same size and features as the TTi MX100TP I just purchased, but with a lower load capability and at a higher price.  What am I missing?  The 11A is the same price, but far less capable.

Better constant current mode (accuracy, noise)? Current readback resolution down to 1 µA? More software support (BenchVue, as opposed to only drivers to interface with your own software)? Stand-alone logging of data?

BTW, gslick, according to the datasheet GPIB is optional for the E36312A/E36313A. It should probably not be listed in the first post as a feature without noting that.

[nctnico]

Some images from the Service Guide:

Dang! They are going to put Dave out of business with service guides like these!

[colorado.rob]

The 12A and 13A seem to be the same size and features as the TTi MX100TP I just purchased, but with a lower load capability and at a higher price.  What am I missing?  The 11A is the same price, but far less capable.

Better constant current mode (accuracy, noise)? Current readback resolution down to 1 µA? More software support (BenchVue, as opposed to only drivers to interface with your own software)? Stand-alone logging of data?

What good does having 1µA readback resolution do you when the level of accuracy quoted is 2-3 orders of magnitude greater?  Specs show 0.04% +3 mA and 0.25% +80 uA readback accuracy.

Given that stand-alone logging and BenchVue software are not features I want or need, the TTi is better value to me.  And, not that it matters to me, the MX100TP comes with GPIB.

[nctnico]

The 12A and 13A seem to be the same size and features as the TTi MX100TP I just purchased, but with a lower load capability and at a higher price.  What am I missing?  The 11A is the same price, but far less capable.

Better constant current mode (accuracy, noise)? Current readback resolution down to 1 µA? More software support (BenchVue, as opposed to only drivers to interface with your own software)? Stand-alone logging of data?

What good does having 1µA readback resolution do you when the level of accuracy quoted is 2-3 orders of magnitude greater?  Specs show 0.04% +3 mA and 0.25% +80 uA readback accuracy.

Given that stand-alone logging and BenchVue software are not features I want or need, the TTi is better value to me.  And, not that it matters to me, the MX100TP comes with GPIB.

The TTi PSU seems like a switcher to me when I look at the weight (approx 5kg). The RMS noise on the TTi PSU is about 10 times larger than this new Keysight series which seems to be linear (approx 8kg). I'm not saying a switching PSU is bad (I have a bunch of them) but sometimes you need a low noise PSU. Also the offset is over the entire temperature range so it may be lower at room temperature. Resolution is nice so at least you can see small changes. I expect the logging feature on these new Keysight PSUs is extremely helpful for low power devices to determine the power profile.

[colorado.rob]

Resolution is nice so at least you can see small changes. I expect the logging feature on these new Keysight PSUs is extremely helpful for low power devices to determine the power profile.

Resolution is meaningless without precision (accuracy).  I suppose one could use the last two digits to feed entropy into a random number generator, so it's not entirely useless.

[nctnico]

Resolution is nice so at least you can see small changes. I expect the logging feature on these new Keysight PSUs is extremely helpful for low power devices to determine the power profile.

Resolution is meaningless without precision (accuracy).  I suppose one could use the last two digits to feed entropy into a random number generator, so it's not entirely useless.

Everything is relative and so are measurements. If the current jumps up or down 10uA then that will likely be a change in the current drawn by the load and not the measurement offset. Either way it is not trivial to measure these kind of low currents going into a ciruit without dropping a significant burden voltage or deteriorating the power supply's out impedance so I'm happy with what I can get.

[colorado.rob]

Either way it is not trivial to measure these kind of low currents going into a ciruit without dropping a significant burden voltage or deteriorating the power supply's out impedance so I'm happy with what I can get.

As long as it meets your needs and you think you're getting value for you money, that's all that matters.  I'd be interested to see a good review and teardown video by someone who knows what they are doing and isn't just a button pusher.

What I really want I cannot have.  I really like the TTi, but I want it in a 2U <300mm depth with the same features on the front panel.  Physically, that cannot happen without some compromises.  The HMC8043 is the right size (and looks nice), but doesn't have binding posts or sense ports in the front.  And the user interface looks like it might be a little challenging with so few buttons compared with the TTi.  And the vent holes on top... 

[TheSteve]

I'd like an E36313A for my bench - wonder when Keysight will have "power supply month".

[Omicron]

This new power supply ticked all the right boxes for me. I ordered an E36312A from Farnell yesterday. It arrived this morning. Haven't had time to play with it much, but one thing I can confirm: the fan in this thing is whisper quiet! I've had fan-less power supplies that made more noise than this one (transformer hum). At my typical use case I simply can't hear it, even in a quiet room (250mA at 24V, room temperature in the office was about 25 degrees celsius). Very happy about that!

[nctnico]

It is good news about the fan! In older HP/Agilent PSUs the fans are usually loud and running at full throttle.

[alm]

Or just went from loud to VERY LOUD.

[HighVoltage]

Because of the noise on older Agilent power supplies, I have exchanged almost all fans and slowed them down. Usually my PSUs don't run at full power, so full fan speed is not required.

Same here, this new Keysight power supplies fulfils everything I was looking for.
I will probably order the E36313A next week.

[anotherlin]

What good does having 1µA readback resolution do you when the level of accuracy quoted is 2-3 orders of magnitude greater?  Specs show 0.04% +3 mA and 0.25% +80 uA readback accuracy.

Specification states that error is (+/-0.04% of the output current) + (+/- 3mA of offset).
If you take a 1mA output current, error is 0.04% of 1mA, which is 0.0004mA (0.4uA), with an offset +/- 3mA.
So according to spec, the actual result can be with within [1 - 3.0004, 1 + 3.00004] mA.

However, most DMM quotes the offset as a % of the range of measurement.
For example my Agilent U3606 5.5 digit DMM, for the lowest 10.000 mA range, specifiies 0.05% of the reading + 0.015% of range.
My 5.5  DMM would be accurate within +/- 2uA if measuring a 1mA current. So its last 1uA digit would not be completely random.

I would rather think that the specified 3mA offset is the most pessimistic value using the highest measurement range of the readback circuit of the PSU.
And that actual performance may be much better, sufficiently that the last 2 uA digits are not completely random when the output current is <= 1mA.

Also the offset/range error is supposed to account for the overall noise of the measurement /readback circuit and this is supposed to be somewhat constant for the design.
So if you do a long log of measurements, you should be able to "null out" that offset error.

[gslick]

According to a picture in the Service Manual they use a STM32F4. This explains the fast startup time of round about 5 seconds in the video from Keysight.
There is already a firmware update available on the website. No wonder to see a USB DFU Updater.
And after a quick look in the Firmware file I think I found some text that belongs to an easter egg

Looking at some of the text strings in the CumuloNimbus_1_0_4_FP_1_0_0_Main_1_04.dfu firmware file it appears that it might be running uC/OS-II.
"uC/OS-II Idle"
"uC/OS-II Stat"
"uC/OS-II Tmr"
"uC/OS-II TmrLock"
"uC/OS-II TmrSignal"

Easter egg text?
"Doe, a deer, a female deer
Ray, a drop of golden sun
Me, a name, I call myself
Far, a long, long way to run
Sew, a needle pulling thread
La, a note to follow So
Tea, a drink with jam and bread"

[Muxr]

They look interesting, although I personally would definitely go for the LAN option so E35312A would be it at a minimum.

[Dubbie]

It's like Keysight was listening when I wrote my post a while back about "Why does no-one make a decent power supply"

I have been on the brink of getting a TTi, But I think I will get the E35312A instead.

The low current feature is great!

[nctnico]

It's like Keysight was listening when I wrote my post a while back about "Why does no-one make a decent power supply"

I have been on the brink of getting a TTi, But I think I will get the E35312A instead.

The low current feature is great!

The low current measurement feature is addictive. I already have an Agilent 66311B PSU which also has a low current measurement feature and it is excellent for low power electronics. I was already looking for a PSU with a high resolution current display but the low current measurement feature is way better.

[HighVoltage]

Since about 6 month I have the Keysight E36103A.
This one has 1 mA and 1 mV resolution and also works really well.

But this morning I was glad they come with a 3 year warranty, because it is not working anymore.
And since all of these new PSUs will not have a schematic anymore, what do we do, when they are outside their 3 year warranty. Then, a repair is not so easy anymore. But that is true for all brands.

The E36102A just sits at 463mA although nothing is hooked up.

[nctnico]

I think I'll put a E36312A on my wish list! Pretty much what I have been looking for in a PSU and the small current + logging features seem very handy to me.

Yesterday I've requested a quotation. Oddly enough I didn't get an immediate response in the e-mail. It also turns out there is a special offer where your get a U1242 handheld DMM for free with many types of equipment (including these power supplies). It's not that I need a new DMM so I'll see what room there is to haggle a bit.

[Dwaine]

That is very disappointing.  You would think in 2017 a power supply would be bullet proof.  With all the documentation and schemic to go with it.

Is it me?  Or is everything going backwards in quality and reliability.  Just yesterday I was using my Dynaco ST70 tube amp and was laughing at the various better and newer amps that won't power up or have their circuit boards dead.

That ST70 just keeps playing and keeps on going.    I had zero problems with it.

Anyone else notice that all the new test equipment these days, you are scared to even turn it on because it will break?

You walk by a new power supply these days and the electrical charge from your stare will send the moffets to magic smoke land.

You spend more time managing your equipment warranties and breakage, than learning or experimenting with new things in electronics.

[Dubbie]

Look up "survivorship bias" Dwaine.

[olkipukki]

Just recently got E36312A and tried it a few days in the row, couple times it became unresponsive at all  , you cannot either switch it off 
workaround - unplug the main cable 

[nctnico]

Just recently got E36312A and tried it a few days in the row, couple times it became unresponsive at all  , you cannot either switch it off 
workaround - unplug the main cable 

That doesn't sound very good. I'm getting one to play with soon to see if it works well (or not).

[alm]

At least it sounds like something that could be fixed with a firmware update. Have you reported it to Keysight yet?

[olkipukki]

Not yet, will try to replicate it. Somehow it happened in the first 5 minutes after boot while I am using knobs and keypad for 1 and 3 channels...

[nctnico]

Keysight E36312A review
Firmware version: 1.0.4-1.0.0-1.04

Look what landed on my desk for a short sleepover:


I guess antracite is the new beige!

The E36312A peeked my interest because I have been looking for a decent lab power supply for a while which has a positive/negative output. Since I have an Agilent 66311B telecom power supply I have grown to appreciate a PSU with an accurate voltage an current readout. No longer a need to hook up external DMMs to measure current and voltage. What sets the Keysight E36312A apart is that it (like the 66311B) has a low current measurement range with uA resolution which is ideal for measuring current consumption in low power circuits. Other power supplies have a 1mA resolution at best.

One of the perks is that you can take screenshots:


And yes, it can also show power consumption in a load:


The binding posts are standard but it can also be ordered with safety banana jacks.

Operation
The operation is quite straightforward. There are two seperate voltage and current knobs. In my opinion the accelleration could be better because turning the voltage or current up takes a large number of spins. OTOH when available I usually use the keypad on instruments to just punch the number in.

One thing I have noticed is that even with the channels off there is a small leakage of around 8uA current flowing when a load is attached.

Current measurement
The low current measurement is one of the features which sets this PSU apart especially when you realise that a DMM has a signficant burden voltage and internal resistance which makes it less suitable for measuring power consumption in digital circuits. Dave did several video's on this subject (including EEVblog #2) but this is a later video which explains it in great detail:
https://youtu.be/jx0dryLmUEQ
Back to the 34461A which doesn't have problems with the burden voltage at all. The resolution is 1uA but my measurements show that the reading can be 7uA off when loaded at 50uA or 500uA (compared to a 34461A). Better than specified but showing a 1uA resolution may be a bit too optimistic. At higher currents the current display (1mA resolution) is spot-on.

Output noise
I compared the output noise using a simple (5uH) LISN between an HP6024A (switching PSU, blue line) and the E36312A (yellow line). The spectrum analyser clearly shows the switching PSU is outputting quite a bit of noise.

 
Fan noise
The fan noise is reasonable; similar to a modern general purpose bench DSO even at full throttle. The fan is temperature controlled and it only runs as fast as needed. Unless loaded to the max this PSU is whisper quiet.

Data logging
This is a nice feature to track power consumption. I tried it with a microcontroller circuit which blinks a LED. The change in the current is clearly visible.

Don't expect too much though because the minimum sample interval is 200ms. I guess Keysight didn't want to get in the way of even more expensive power supplies (like the 66311B) which can sample at much higher frequencies in order to study start-up behaviour of low power devices in great detail.

Switch on/off behaviour
I did some measurements using a purely resistive DC-load, a scope, a current shunt and a regular probe to look at power on/off behaviour. The yellow trace is the current, the blue trace the voltage. The voltage is set to 20V and the current limit to 1A.

Switch-on no load


Switch-on 20 Ohm load


Switch-off no load


Switch-off 20 Ohm load


Unplug no load


Unplug 20 Ohm load


All in all this looks good. No overshoot and no funny business when the mains is suddenly interrupted.

Short circuit protection behaviour
My resistive DC-load can switch to a near full short and back to normal extremely fast because it uses an open-loop design. This makes it a good tool for looking at power supply behaviour. Again the voltage is set to 20V and the current limit to 1A.




The graph shows discharging the output capacitors, recharging them and some overshoot (250mV).

Load change behaviour
Switching between 1A and 300mA loads (20V and the current limit at 1A.):



Power sequencing
I did not test this but the E36312A is able to perform switch-on and switch-off sequencing between the channels so you can use it for loads which require this.

Conclusion
I think this is a very nice power supply. Sure it is very expensive compared to other power supplies but I think having the accurate readouts is worth the money because it makes life so much easier and no need to buy extra DMMs. The one I have is a demo model which has to go back but I think I'll order one soon. I'm going to play with the demo model a bit more to see how it holds up.

[alm]

Thanks for that review! Looks like a solid performer without major flaws and with some unique features.

[Dubbie]

Thanks for the review nctnico! I think you've sold me. I hope you get a commission!

[HighVoltage]

nctnico,
Very nice to do a review like this.
Now I am even more inclined to order one.
 

[sdouble]

does someone know whether the 6V output is as clean as the 25V ?

It's often not the case in triple outputs PSU.

[nctnico]

does someone know whether the 6V output is as clean as the 25V ?

It's often not the case in triple outputs PSU.

I just tested all channels with my LISN and a DC load. In 10kHz to 100kHz frequency range the 6V output (output 1) seems to be cleaner. At higher frequencies all the outputs are more or less the same.

yellow=base line
green=output 1
blue=output 2
purple=output 3

Edit: all outputs tested @5V with an approx. 500mA load.

[sdouble]

thanks. looks really nice.
gonna buy one very soon.
need to find a distributor in france first.

[nctnico]

thanks. looks really nice.
gonna buy one very soon.
need to find a distributor in france first.

You can create a user profile on Keysight's website and ask for a quotation. Keysight will forward that to the local distributor. However other (online) shops may sell it as well.

[anotherlin]

thanks. looks really nice.
gonna buy one very soon.
need to find a distributor in france first.

Farnell has a few in stocks and they currently have the offer with a free Keysight handheld multimeter.
Shipping (UPS) to France is free.

[mk_]

I just tested all channels with my LISN and a DC load. In 10kHz to 100kHz frequency range the 6V output (output 1) seems to be cleaner. At higher frequencies all the outputs are more or less the same.

How was the LISN connected and the overall measurement-setup?

Asking, because I`m not sure how to use the LISN for measurements like this..

Michael

[nctnico]

I just tested all channels with my LISN and a DC load. In 10kHz to 100kHz frequency range the 6V output (output 1) seems to be cleaner. At higher frequencies all the outputs are more or less the same.

How was the LISN connected and the overall measurement-setup?

Asking, because I`m not sure how to use the LISN for measurements like this..

PSU at the DUT side and the load at the PSU side. Basically reverse flow of 'normal' but keep in mind to look at the measurements in a relative way because the setup I used is nowhere near the official setup and let's not even mention calibration.

[pe1oxp]

Just did some small tests with an E36312A. After switching off the power supply I heard the fan.
It seems that the power supply can't be totally switched off. Only by removing the mains cord.

Measured power consumption:
Off:  10.1W  13.2VA (Cos-Phi 0.75)
On :  12.1W  15.6VA

A lot of wasted power when you use the bench power supply not every day.

[alm]

That sounds odd. Are you sure it is not just that the fan keeps running for a while after turning of the supply to keep the temperature down. Not that I have seen this in power supplies before, but it would seem more likely than designing something with such a ridiculous standby power usage. I wonder if this is some sort of defect, do other owners measure the same?

[pe1oxp]

That sounds odd. Are you sure it is not just that the fan keeps running for a while after turning of the supply to keep the temperature down. Not that I have seen this in power supplies before, but it would seem more likely than designing something with such a ridiculous standby power usage. I wonder if this is some sort of defect, do other owners measure the same?

I mentioned it the next morning after using the power supply and tested it a few times now, after plugging in the mains lead the fan starts running slowly directly. So most of the electronics inside must be powered up. The difference between both power states seems only be caused by the display and of course all buttons don't work.

[bitseeker]

That sounds really odd. Does anyone else's 12A or 13A also have this always-in-standby behavior?

[adamgreig]

Just checked my '12A and I see the same 10.4W standby, 12.5W or so active but no channels enabled. Hasn't been turned on all day so definitely isn't to finish cooling down after a heavy workout or anything.

Pretty weird. I think I can just about hear the fan (something of a pain to look at the back with my setup) but it's extremely quiet, I wouldn't have noticed if I wasn't looking for it.

[Keysight DanielBogdanoff]

I've been using an E36312A casually for the last couple weeks and can confirm that the fan does turn on even if the unit is turned off - but the fan is really, really quiet. So, there's not an audible noise issue for me at all.

I'll talk to that team and see what they say about the standby power consumption. If it's an issue, you can always run a hard switch with a power strip.

Overall, though, I've been loving the supply.

[mrwilby]

Just checked my '12A and I see the same 10.4W standby, 12.5W or so active but no channels enabled. Hasn't been turned on all day so definitely isn't to finish cooling down after a heavy workout or anything.

Pretty weird. I think I can just about hear the fan (something of a pain to look at the back with my setup) but it's extremely quiet, I wouldn't have noticed if I wasn't looking for it.

I have one of these on order. This kind of "standby" consumption is really not acceptable in this day and age...

[bitseeker]

Hopefully, it's just a firmware change. It's not like the supply has an OCXO to keep warm.

[alm]

Maybe they did it to reduce boot time? But I agree that for a bench supply, that unlike a system power supply is usually only used for eight or so hours per day, this is ridiculous.

[pe1oxp]

I have one of these on order. This kind of "standby" consumption is really not acceptable in this day and age...

~92kWh a year, for me about EUR 20,- extra costs. What is about 8% of my total consumption per year for my whole house.

[mrwilby]

...
I'll talk to that team and see what they say about the standby power consumption. If it's an issue, you can always run a hard switch with a power strip.

Daniel, just checking in - was there any update on the team with regards to the power consumption issue discussed earlier in the thread? TIA!

[sauerwald]

Looks like a nice basic bench supply.
A few nits that I would pick:
1)  In the video they talk about current measurement down to 100uA, but the display is showing a resolution of 1uA, and with no load connected, the current is non-zero.  I hate it when a result is displayed with more resolution than accuracy - which happens with 93.85326% of test equipment vendors.

2)  Someone mentioned not liking the 'kindergarten colors' for the outputs - I do like this.  In my job (validation engineer for a semiconductor company) I will often have several different test boards for the same part, and I color code the cables for power to make it easy to figure out which supply goes where - by matching cable colors to the channel numbers it will make life easier.

3)  I like the supply sequencing feature, but I suspect that it is not possible to tie multiple supplies together and sequence across two or more power supplies - I often have to sequence more than 3 supplies.

[nctnico]

Looks like a nice basic bench supply.
A few nits that I would pick:
1)  In the video they talk about current measurement down to 100uA, but the display is showing a resolution of 1uA, and with no load connected, the current is non-zero.  I hate it when a result is displayed with more resolution than accuracy - which happens with 93.85326% of test equipment vendors.

The unit I had on loan was accurate to less than 10uA so it makes sense to show a resolution of 1uA.

[alm]

Resolution beyond accuracy can be useful for observing relative changes. Is the current drifting up or down? Accuracy beyond resolution is wasted.

The only problem is people too lazy to check the equipment specs before taking a critical measurements.

[Andrew]

My E36312A has arrived , eight weeks from order they must be popular?

Keysight have a new promotion that includes this series of supplies (promotion code: 6.023), however as mine was ordered in August I wanted to take advantage of the previous promotion, code: 6.015. This is valid up to 31st Dec 2017 for items purchased between 1st April and 30th September 2017.

I think there is a problem with the webpage. Choosing either E36311A, E36312A or E36313A from the "Model Number" drop-down list results in the all important "Serial Number", "Purchase Date" and "Purchased From" textboxes disappearing.

Would a kind soul try the page and let me know of similar action?

www.keysight.com/find/BIG5BenchClaim

Yes, I'd like claim the U1242C to replace my "one hung low" special.

[nctnico]

It seems all good things come to those who wait  Now they throw in a free U1282A dmm. I just pulled the trigger on a E36313A. That is the 160W version but when it comes to accuracy the specs are very close to the 80W version. For me the 80W version isn't going to cut it for a number of projects I find on my bench regulary.

Edit: these PSUs seems to be popular. I have to wait nearly two more months before it will be delivered! 

[Ahrenp]

Anyone with one of these units notice an audible hum when the unit is "off"? Mine (E36312A) has a low hum when I'm sitting in a quiet room with everything off; it's not noticeable at all when other gear is on though. It seems to alternate periodically from a steady hum to alternating on/off every couple seconds or so.

[Fred27]

It's definitely still "on" even powered down. That's a soft power switch. I think it draws about 10W on standby too.

[HighVoltage]

I have the E36312A and there is no hum at all.

But there are a few firmware issues I have come across that are very annoying.
Sometimes the PSU just stops responding and I need to unplug the instrument for a power cycle, since the soft power switch is then also not responding.

What I find also annoying:
The voltage turning knob can increase the output by 1mV per indent.
But the real output is not increasing by the same amount for each indent.
In other words, there is a big difference between the set point the actual readout and what is measured externally with a different meter.
Hmm, seems like a firmware bug as well.
This could be much more precise.

[adamgreig]

I think the hum might be the fan occasionally spinning up?

This video (which nihtila posted on the contest thread) highlights a bunch of bugs and options for improvement, perhaps including your issue HighVoltage:

[nctnico]

Why would you want to use the knob to adjust the voltage? On PSUs with a keypad I just punch the number in. Much quicker and easier.

[Ahrenp]

I think the hum might be the fan occasionally spinning up?

It's don't think it's the fan, I can hear the fan ramp up when I power it on and the hum remains in the background. It's not a huge deal but when I'm on my nearby PC (which is dead silent) with nothing else in the room on, there's just a slight, annoying hum. I was just curious if it was typical of these power supplies. If everything is turned off I might start flipping off the power bar because I don't see any reason for it to be humming and drawing 10W all the time.

[HighVoltage]

Why would you want to use the knob to adjust the voltage? On PSUs with a keypad I just punch the number in. Much quicker and easier.

Usually I also just enter the numbers on the keypad and it works really well.
Finally a Keysight PSU with a keypad !

But the other day I needed to ramp up the voltage in mV steps and used the knob, expecting every step to be 1 mV change. But then to my surprise this was not a linear increase. May be it is nitpicking?

[Fgrir]

The voltage turning knob can increase the output by 1mV per indent.
But the real output is not increasing by the same amount for each indent.
In other words, there is a big difference between the set point the actual readout and what is measured externally with a different meter.

I've been eyeing these supplies for a while so I'm curious, how big a step size are you actually seeing with your 1mV setting changes?

The front panel controls are all spec'd with 1mV steps, but the remote programming resolution for the E36312A is 0.36V for the 6V output and 1.5mV for the 25V outputs.  Perhaps these represent the real hardware resolution (14 bits???), and all you are seeing is the quantization error of mapping the 1mV steps onto this.

Of course if you are seeing larger steps then this wouldn't be an explanation at all...

[adamgreig]

A while ago I ran a little test with the E36312A ch1 hooked up to my 34465A, and recorded the difference between measured voltage on the '65, and both the programmed and readback voltage on the 36312A. I did it over a few spans but this first one is the only one with mV steps. Also attached is over the whole 0-6V span. It's not bad all around, error tends to be within a fraction of a mV.

[nctnico]

The voltage turning knob can increase the output by 1mV per indent.
But the real output is not increasing by the same amount for each indent.
In other words, there is a big difference between the set point the actual readout and what is measured externally with a different meter.

I've been eyeing these supplies for a while so I'm curious, how big a step size are you actually seeing with your 1mV setting changes?

The front panel controls are all spec'd with 1mV steps, but the remote programming resolution for the E36312A is 0.36V for the 6V output and 1.5mV for the 25V outputs.  Perhaps these represent the real hardware resolution (14 bits???), and all you are seeing is the quantization error of mapping the 1mV steps onto this.

You have a very valid point here and something very similar is going on with HP's older telecom DC power supplies like the 66311B. The programming and readback accuracy are different. Add the inaccuracies of the circuitry to that and it is clear that changing the setting (=programming) by 1mV isn't going to match the readback reading.

[adamgreig]

Here's a more direct comparison. Increment in 1mV steps around 3V, shows the PSU readback vs the DMM readback. I think it's pretty close to incrementing by a mV each time you crank the knob by 1mV.

[Ahrenp]

Here is an example of what mine sounds like. Audio quality isn't great but you can hear it. The only other thing running is my obnoxiously loud clock.

[LaurentR]

I've been using an E36312A casually for the last couple weeks and can confirm that the fan does turn on even if the unit is turned off - but the fan is really, really quiet. So, there's not an audible noise issue for me at all.

I'll talk to that team and see what they say about the standby power consumption. If it's an issue, you can always run a hard switch with a power strip.

Overall, though, I've been loving the supply.

Daniel, do you have any information on potential firmware updates for the PSU?

I'd also like to know if anything will be done to the accelerating V and A knobs.
I have tried the E36313A (considering getting one) and I am not convinced at all this is right for a PSU.
I like having a knob to step the PSU (i.e. with a fixed step). That's how most other similar knobs work (including from Keysight, e.g. on the 33522B AWG - pick a significant digit and step it up or down).
But the whole thing about quickly adjusting the voltage, I don't get it. I use the keyboard for that. It's actually faster than accelerating to the right area and decelerating at the right time and most likely going back some.

[glowitz]

I have an E36313A and get a similar audio buzzing noise even when powered down (powering up can still yield the buzzing noise). I tried uploading the audio file but it's too large. Suffice to say that this happens even when the unit is powered down (but plugged in). My symptom is it lasts for 1-2 seconds, then goes quiet. It doesn't sound like the fan turning on (why should it anyway, when it's been off for a long lime). It sounds like some 60 or 120 Hz buzzing that is very audible. I was able to capture the current and voltage going into the supply and the current spikes nearly 1A when the buzzing starts, then it drops back down. This is with the supply turned off. Now that I see someone else with this problem, I believe my situation is not unique and that there may be environmental situations that could be interacting with the power supply circuitry (such as plugged into a power strip with a surge protector, etc). Who knows, but it's very strange for sure. I have also come a cross many UI bugs, most of which I believe have already been discovered and reported on this forum, including total instrument lockup, which needs to be fixed fast.

[glowitz]

adamgreig - thank you for your comprehensive and excellent review. Do you know whether Keysight engineering has seen your video yet? They need to and I encouraged the Keysight support team to have a look as well. I have run into many of the same issues (although you've found many more). I've reported them to Keysight as well. The egregious bugs like locking up indicates very poor software QA and there is no excuse. If something is in a rack or bench top, it's not easy to unplug it always to reset it. I'm not clear how these could have passed the kind of rigorous process I used to know (I worked for the original HP T&M division for 13 years). Makes me wonder if this is an OEM product and Keysight relied on third-parties to design and test it. I hope not for the price. They really need to improve the software to make the UI more usable, less prone to errors, and obviously fix the bugs impacting usability. Also, I remember now if you mentioned it, but when you save and recall settings, it does not recall the Logging setup either. Maybe this isn't a bug per-se, but it's a pain because I want to be able to save and recall the instrument setup, including the logging feature. It can take a bit of time to reprogram the logger setup, especially when the unit completely hangs up!

In addition, I have experienced the same issue as you with inadvertently adjusting the current or voltage not realizing that the active area was something else. As a result, I accidentally applied 20V to a diode (good bye diode) when I was trying to current limit to 20 mA. This is simply due to the way the UI works. Yes, my fault, but too easy to make an error.

I also have the issue that others have reported of a periodic buzzing noise of the unit (even when powered down). During this condition, it draws an extra amp of current for a couple of seconds, then goes back to its quiescent state. It sounds like a fairly loud "buzz" or oscillation of the power supply, even while turned off. Keysight wants my unit back for evaluation but after visiting this forum I see that at least one or two others have reported similar issues with an audible buzz or noise. In my case, the fan is not on -- as it happens even overnight with nothing turned on (I've captured the transient in a power data logger, showing the instrument side of the load).

Anyway, great review. You captured so many of my frustrations with this unit. To be clear, I'm an avid supporter of Keysight/Agilent/HP T&M equipment. But with this unit, I feel like they lost their magic touch and that with some software improvements, they will have an outstanding piece of gear. Otherwise, it's a frustrating experience and I'm tired of pulling out the cord to reset it. No excuse, Keysight! Put your best on this to fix these things and please watch this video from adamgreig. Customers don't take time to do this because they want to waste their day. They do it because they love the brand and want the products to work in a way that's intuitive and reliable.

[Ahrenp]

Keysight wants my unit back for evaluation but after visiting this forum I see that at least one or two others have reported similar issues with an audible buzz or noise. In my case, the fan is not on -- as it happens even overnight with nothing turned on (I've captured the transient in a power data logger, showing the instrument side of the load).

Your buzzing issues sound exactly like mine. I have contacted Keysight with this issue as well but it has been several days and I have not yet heard back from them. For now I guess I will continue to turn off my surge protector after every use.

[adamgreig]

Hey glowitz, just to be clear, it's not my video - I just found it on the contest forum thread and re-posted it here! Though I have also encountered the occasional hard UI lock-up and the video's suggestions for other features are excellent. On the whole I've found since I mostly just type in my desired voltage and current it works extremely well and has been significantly nicer to use than my old adjutable-pot PSUs. Just that with a few firmware tweaks it could be nicer still!

I notice the JTAG port for the STM32 running the show is extremely easily accessible, and the current firmware image is available for download, which suggests some mileage in aftermarket firmware...

[Keysight DanielBogdanoff]

Just so everyone knows, we are monitoring this thread. I have no info right now regarding updates, but will be sure to alert you all once I have info!

[bitseeker]

Thanks, Daniel. I hope you get a big Christmas bonus. It seems you've become Keysight's spokesman and friend of the community for every product line they make.

[Ahrenp]

Today I wanted to do some quick LED voltage measurements for a Christmas decoration project I am working on. I set the channel one voltage on my E36312A to 5V and the current limit to 10mA. I expected the power supply to limit output 10mA at the LED forward voltage, but instead I got an output of 5.000V at 19.266mA. 

Also, to quiet down the buzzing when not in use, I have been switching off my surge protector. This results in almost 8V open circuit at the output of channel 1 when I turn my surge protector on, or ~0.3V, 3.8A short circuit, which was enough to kill a bunch of breadboarded LEDs. So I guess from now on I'll be disconnecting everything in addition to turning of my surge protector.

Am I just being picky at this point? I feel like these things should not be issues on an $1800CAD instrument.

[nctnico]

I agree these issues don't instill much confidence. How is it possible that it outputs a boatload of current when you plug it in? This is definitely something I want to test!

The current programming accuracy is specced at +/-3mA and 0.04%. 20mA versus 10mA is way out of spec but OTOH trying to program currents with a precission of several mA isn't going to happen with this power supply.

[adamgreig]

I tested just turning on/off from the front and there's no voltage or current to speak of, but when plugging in the mains supply it's another story. Hooked up channel 1 to my 34465A I get these for open circuit voltage and short circuit current:



This is just plugging in, not turning on. It's pretty repeatable, and it does last twice as long open circuit as it does short circuit. Might be interesting to try with an active load to measure the energy available. I think this is pretty standard for many budget bench PSUs though at least this doesn't have problems if left plugged in.

[Dubbie]

I often use my Rigol to output low currents for checking LED brightnesses at various currents. While it's not mA accurate, it's within 2-3mA of the display reading at the sub 30mA range. (confirmed with my keysight bench meter)

I have been keen on buying one of these power supplies, but so far it looks WORSE than the Rigol which is 1/4 the price. The 10W standby power is unacceptable also. What on earth is it being used for?

[nctnico]

I have been keen on buying one of these power supplies, but so far it looks WORSE than the Rigol which is 1/4 the price.

The 10W standby power is unacceptable also. What on earth is it being used for?

I'm wondering about the same. I was thinking of modding it to have a real power switch but if the price for that is blowing up anything sensitive connected to it when switching it on then that is no solution either. I'm starting to lean towards cancelling my order because this kind of behaviour is not acceptable for a PSU. With two EEVblog members reporting/showing the same issue it isn't a matter of a defective unit either.
I already played with one of these power supplies but I only tested what happens when the mains are switched off. That showed no overshoot or any other funny stuff. I kinda assumed it would have well defined start-up behaviour as well.

[Dubbie]

Just to put my money where my mouth is, I just measured the CC setpoint performance of my rigol with an LED backlight hooked up.
It's actually better than I thought.

I had the voltage set to 6V

Power Supply is the Rigol DP832, Meter is Keysight 34461A

[adamgreig]

For comparison this is the E36312A ch1 short circuited into the 34465A. The readback error is better than ±0.1mA and the difference to the DMM is better than ±0.3mA (except at the 1mA setpoint). The errors stay well within a 1mA up to 1A output.





edit: I tested with an LED in series too, no difference. I can't reproduce the problem Ahrenp had.

[Dubbie]

Thats more in line with what I would expect adamgreig.

Looks like about 1/3 the error of the Rigol.

I wonder what Ahrenp's problem was? Maybe a hardware fault.

Here is the Rigol error graph for direct comparison:

[Ahrenp]

Upon further testing, it would seem that the threshold to go into CC mode is around 10mA.

If I connect an LED across the output and set the supply to some voltage below the LEDs expected forward voltage at 10mA, supply current set to 10mA, and then start turning up the voltage, the supply will stay in CV mode and the current will rise to >20mA before CC mode kicks on and brings the voltage down. In my previous test with blue LEDs my 5V set-point was not high enough to drive more than 20mA through the LED and therefore the supply stayed in CV mode. If I had set my voltage higher, >>Vf of my blue LEDs, I would not have had an issue. Once CC mode is enabled programming/readback accuracy are within spec.

Still not impressed with the spikes on the output when plugging it in/turning on the power bar though.

[HighVoltage]

I just tested my E36312A with the following conditions:

All 3 Channels turned OFF
All 3 Channels set to 0.000V
Channel 1 set to 5A
Channel 2 set to 1A
Channel 3 set to 1A

Then I hooked up my 34470A to measure the voltage and current spike, when the instrument is connected to mains power. (Turning mains 230V suddenly ON).

Here are the results:
Channel 1 Voltage Spike: 3.69 V
Channel 2 Voltage Spike: 1.97 mV
Channel 3 Voltage Spike: 8.02 V

Channel 1 Current Spike: 1.95 A
Channel 2 Current Spike: 2.50 mA
Channel 3 Current Spike: 485 mA

[HighVoltage]

Here is a current output profile, captured with a scope and current probe after a sudden mains turn-ON of the PSU.

Again, voltage set to 0.0 and current set to 5.0
There are two spikes in the current, >12.7A

Well, as long as we know, not to turn the PSU ON while it is connected to a circuit, all should be OK
But it would be nice, if Keysight could fix this problem through a FW update.

[nctnico]

Keysight has to fix this. What if there is a short interruption in the mains?

[HighVoltage]

Here is another behavior, I have not seen before in an Agilent / Keysight PSU.

Make a parallel connection to all 3 outputs with external cables.
Output 2 and 3 are turned OFF
Limit Output 1 to 1V and 10 mA

Then turn only output 1 ON (Output 2 and 3 are still turned OFF)

Result:
Spike of 564 mA for a few micro seconds before it regulates to 10 mA after about 500 us

Or is this to be expected for such a setup?

[TheSteve]

So a power outage is a bit of a scary thought if you have something expensive/delicate connected.
I am sure this actually applies to quite a few supplies/SMU's though.

[nctnico]

So a power outage is a bit of a scary thought if you have something expensive/delicate connected.
I am sure this actually applies to quite a few supplies/SMU's though.

I'm pretty sure this PSU is an exception in this price class. Think about when a power supply is tied into an automated test setup where you just can't disconnect the PSU.

I've checked a bunch of PSUs:
GW Instek PSP-603
Voltcraft PS-1302
HP 6012A
HP 66311B
HP 6572A

These PSUs range from 45W to 2000W so I think I got a bit of everything. Only the HP6012A showed a 1.5V spike on startup with the output adjusted to zero. The rest showed nothing at all.

[Keysight DanielBogdanoff]

Quick update. There are a number of bug fixes in the works, especially around things that cause the supply to hang/crash. I'm working to get you all a beta code release, but nothing official will come out until the January time frame.

R&D is monitoring this thread as well.

Thanks for your patience!

[nctnico]

Quick update. There are a number of bug fixes in the works, especially around things that cause the supply to hang/crash. I'm working to get you all a beta code release, but nothing official will come out until the January time frame.

R&D is monitoring this thread as well.

Thanks for your patience!

Daniel,
Can you please comment on whether the voltage spikes (when mains gets connected) will be fixed or not. For me they are an absolute deal breaker.

[HighVoltage]

I'm working to get you all a beta code release,

Thank you, Daniel, this is really appreciated!

[Keysight DanielBogdanoff]

@nctnico I don't know yet, but I'll let you know!

[Andrey_irk]

Upon further testing, it would seem that the threshold to go into CC mode is around 10mA.

If I connect an LED across the output and set the supply to some voltage below the LEDs expected forward voltage at 10mA, supply current set to 10mA, and then start turning up the voltage, the supply will stay in CV mode and the current will rise to >20mA before CC mode kicks on and brings the voltage down. In my previous test with blue LEDs my 5V set-point was not high enough to drive more than 20mA through the LED and therefore the supply stayed in CV mode. If I had set my voltage higher, >>Vf of my blue LEDs, I would not have had an issue. Once CC mode is enabled programming/readback accuracy are within spec.

Still not impressed with the spikes on the output when plugging it in/turning on the power bar though.

What output capacitance does it have? Maybe it is enough to kill an LED when it switches from CV to CC. And if it is so then there is nothing they can do.

Has anyone figured the way it works? Does it have multiple secondaries or a preregulator? A lot of wires coming from the transformer suggest multiple windings, but why do they need these big caps then?

[nctnico]

Any PSU ramps up the output until either CV or CC is hit after you enable the outputs and with the load attached. OTOH the output capacitor will discharge first before going into CC mode if you connect a load after the output has been enabled.

[Andrey_irk]

Any PSU ramps up the output until either CV or CC is hit after you enable the outputs and with the load attached. OTOH the output capacitor will discharge first before going into CC mode if you connect a load after the output has been enabled.

This is why people build power supplies without output capacitors.

[rsjsouza]

I am not sure if this is just my impression or not, but last night I entered my lab space (the laundry room) with the lights out and it seemed that my E36312A had the TFT backlight on with the power supply off.

It may have been the reflection of the yellow standby LED, but the dim glow looked too evenly distributed across the display.

Does anybody else see this?

[Keysight DanielBogdanoff]

Hi Everyone,

Good news, I have beta code with some fixes: http://bit.ly/E3631x_Beta

Use at your own risk! It hasn't been fully QA tested, and I haven't even able to test it myself since I'm on Christmas break.

I also don't have a change log yet, I'm working on getting one. If by some chance you end up with a fatal error, please post here and message me so we can handle it.

Official code is scheduled for February. I'll do my best to get a change log, but am also expecting a new kiddo any day now so life might get crazy fast .

Thanks!

[bitseeker]

new kiddo

Congratulations, Daniel!

[TheSteve]

new kiddo

Now you'll have to share the scopes!

[pmcouto]

I am not sure if this is just my impression or not, but last night I entered my lab space (the laundry room) with the lights out and it seemed that my E36312A had the TFT backlight on with the power supply off.

It may have been the reflection of the yellow standby LED, but the dim glow looked too evenly distributed across the display.

Does anybody else see this?

Yes!

The backlight is not fully on, but there's a faint light coming from the display when the PSU is in standby.

[nctnico]

Can someone test whether this has fixed the startup issues?

@Daniel: thanks for making this available! I hope everything goes well and your new born is healthy. If it is the first: be sure to be there when it is born. If it is not then you probably already know that you need to be there when the magic happens 

[HighVoltage]

Thanks Daniel and congratulations!
I wish you all the best but especially good health for the newborn and the mother.

I am updating the firmware right now and then will run a few tests

[HighVoltage]

The Firmware update went smooth from FW 1.04 to FW 1.08 with the PC firmware utility.

[HighVoltage]

Ok, here are the results.
Not so good, when power is switched ON, on the mains level, these are the results:

[HighVoltage]

The good thing so far with the new FW:

I have not been able to crash the PSU by pushing some buttons as before.
It seems Keysight have implemented some good changes.

What I find also interesting...
The new FW shows the PSU model number on the top left corner of the display.
Hmm ... but why would it only say E3631A instead of E36312A?

[bitseeker]

The new FW shows the PSU model number on the top left corner of the display.
Hmm ... but why would it only say E3631A instead of E36312A?

An homage to its ancestor.

[Ryl]

Hi guys,

I'm interested in the E36312A!
However, I am a private consumer and cannot order through a company.
Does anyone know about any website located in Europe that could ship the E36312A (within very short delay at the standard price) to a private consumer in Belgium?
I really could not find any (Farnell, RS, Mouser, Digikey and others failed meeting all the conditions above)...

Thanks!

[nctnico]

Hi guys,

I'm interested in the E36312A!
However, I am a private consumer and cannot order through a company.
Does anyone know about any website located in Europe that could ship the E36312A (within very short delay at the standard price) to a private consumer in Belgium?
I really could not find any (Farnell, RS, Mouser, Digikey and others failed meeting all the conditions above)...

Try Eleshop.nl . They have Keysight multimeters so maybe they can deliver the E36312A as well. OTOH I think Farnell offers a way to order for non-companies so check their website.

[Ryl]

Thanks for the advice on Eleshop.nl, I'll contact them to ask if they can order it and if they can deliver it quickly.
Regarding Farnell, they redirect to sinuss.be (their partner website for private consumers), but there the E36312A costs 160€ more and is out of stock without possibility to order it.
In case eleshop replies they cannot order it, I'm still listening to any other advice for ordering the E36312A to a private consumer in Belgium, thanks!

[HighVoltage]

I am sure you can order one at Meilhaus as a private person with shipping to BE.
But it has 2-3 weeks delivery time.

https://www.meilhaus.de/e36312a.htm

[Ryl]

Thanks for the advice.
Unfortunately, I find this field in the form: "VAT No. ( required for bussines clients from EU - no sales to private/consumer customers)".

[pe1oxp]

Try Distrelec, I bought it from them, you can create a private account.
Unfortunately for you they had till 22 December a 15% discount on there whole product range with a coupon code

[Ryl]

Thanks pe1oxp, Distrelec seems to be just fine!
New units seem to arrive within one week, so that's not in stock but it's okay.
Too bad for the 15% discount.
Do they propose such discounts regularly?

[HighVoltage]

Thanks pe1oxp, Distrelec seems to be just fine!
New units seem to arrive within one week, so that's not in stock but it's okay.
Too bad for the 15% discount.
Do they propose such discounts regularly?

I have a 10% off code for Distrelec that I have not used, valid to 12-31-2017.
I am just not sure if it is limited to my account.
It is only valid for regular priced items.
PM me, if you want it.

[nctnico]

Ok, here are the results.
Not so good, when power is switched ON, on the mains level, these are the results:

To me is seems they only fixed the power on spike on channel 3. Channel 1 seems to be unchanged.

[HighVoltage]

Ok, here are the results.
Not so good, when power is switched ON, on the mains level, these are the results:

To me is seems they only fixed the power on spike on channel 3. Channel 1 seems to be unchanged.

Yes, you are correct, there are no changes on Channel 1.

Actually the current output from Channel 1 after a mains cycle, killed the 3A fuse on my 34470A on the 3A input.
I probably should have known better and have it hooked up to the 10A input when I started.

Hopefully the PSU can be fixed through a firmware update and does not require a hardware change
for this mains spike.

[TiN]

Anyone having issues with USB 3.0-type sticks? I tried three different drives, none of them work with either 1.04 or 1.08 beta FW.
I was assuming that USB 3.0 signals just unconnected on the PSU, but should be still functional in USB 2.0 mode. Same sticks work fine on other gear,  like Tek scope.

1.04 firmware was detecting sticks, but not saving anything. Datalogging also unable to start/use either.
1.08 firmware says "Unsupported USB stick" and that's it.

[HighVoltage]

I have only tried USB 2.0 compatible sticks so far and had no issues
Tomorrow I can try a USB 3.0 stick

[adamgreig]

My 32G USB3 stick works OK on both 1.04 and 1.08 beta, usb detected and screenshots save OK. Might just be the specific stick?

[sdouble]

can someone confirm that the low current reading is only available on model E36312A an  E36313A ?

[pe1oxp]

Anyone aware of delivery or production problems with these power supplies?
Order of a E36313A placed in December last year is now scheduled for 14 February or some later. At moment of ordering it was confirmed for 18 January.
Maybe some hardware fixes or upgrade firmware?

[nctnico]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

[pe1oxp]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

My ordered E36313A has also had in the meantime a confirmation of 26 January but when I looked yesterday on the suppliers website they mentioned 3 weeks later.
I asked and they confirmed the delay.

[nctnico]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

[Messtechniker]

I will very much hesitate buy one of these E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
because these belong to the not so large group of  benchtop supplies where + is on the  left and - is on the right.
This can be highly confusing when mixed with units where - is on the  left and + is on the  right, as is the case for the majority of benchtop supplies.
At least KS have in this case maintained the semi-standardized colour code for - =  black and + = red.

Even colour coding the COM terminal instead of the Volts input on my VC 940 (UT71) meter gets me confused from time to time
when tired or needing to do things quickly.

[nctnico]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

As expected channel 1 still has a spike for several hundred ms when mains are applied: 7.7V when loaded with 820 Ohm and 12A when shorted.

[glowitz]

Daniel, maybe I missed it in all the threads. Were you able to obtain preliminary release notes or even a cryptic bug-list of items allegedly fixed or improved in this beta release (just so we don't have to guess and retest every parameter or UI trap?). And do you know whether there has been an updated version of the beta given that some people have still reported issues, such as with the turn-on spikes, etc? I'm interested in any bug fixes as well as other UI improvements. My Keysight rep has asked me to document the list of issues I've found (as well as UI suggestions), but I don't want to waste time on stuff that's already been or planned to be implemented in the upcoming release. Thanks in advance!

[pe1oxp]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

My expected delivery date is now changed to March grrrrr

[nctnico]

After using the E36313A for a while now and I start to miss something: I think it should remember the last settings so the next time you power it on it already has the previous settings. I have been working on projects which need the parallel mode or series mode and it is kinda tedious to have to setup the PSU from scratch every day.

[glowitz]

I believe you can set a SAVE state to be the "POWER UP" mode. Note that the current (release) firmware does have a bug that can cause the unit to hang after recalling a state. I haven't tried this, though, with the power-on setting which should happen automatically upon power-up. New firmware in the works should resolve this issue in any case.

[nctnico]

I know it can do that but for a bench power supply it would be nice if it can keep the last settings without needing to push any buttons. Saving & recalling a preset takes more button presses than setting it up again.

[glowitz]

I think once you assign a state as a power-up mode, it will save it and automatically recall it. But if you're saying you don't even want to save it, then yes, it doesn't do that. You would have to save it each time if your condition is changing.

[nctnico]

I think once you assign a state as a power-up mode, it will save it and automatically recall it. But if you're saying you don't even want to save it, then yes, it doesn't do that. You would have to save it each time if your condition is changing.

But again: I wished it behaved more like (for example) an oscilloscope. Turn it on the next day and you can continue where you where the day before.
I have a PSU from a different brand and that does retain it's settings.

[glowitz]

It's a good idea. Perhaps there could be a setting in the utility menu to enable/disable "remember last setting on power up". I can see some situations where you would not want to have prior settings activated (as it could potentially blow up a new circuit if the next user wasn't aware or forgot).

[Dubbie]

this forgetfulness would bug the crap out of me.
I have my rigol set up in a way that I use 80% of the time. Usually, I can just flick the power switch then enable the output. It would infuriate me if I had to dial it in every single time.

[nctnico]

this forgetfulness would bug the crap out of me.
I have my rigol set up in a way that I use 80% of the time. Usually, I can just flick the power switch then enable the output. It would infuriate me if I had to dial it in every single time.

You can set the default the way you like it (and have 10 presets) so if you mostly use 5V you can have that as a default.

[pe1oxp]

Hi Everyone,

Good news, I have beta code with some fixes: http://bit.ly/E3631x_Beta

Use at your own risk! It hasn't been fully QA tested, and I haven't even able to test it myself since I'm on Christmas break.

I also don't have a change log yet, I'm working on getting one. If by some chance you end up with a fatal error, please post here and message me so we can handle it.

Official code is scheduled for February. I'll do my best to get a change log, but am also expecting a new kiddo any day now so life might get crazy fast .

Thanks!

Any news about the expected new firmware?
Received my power supply with the 'old' firmware.

[pe1oxp]

Anyone tried the new firmware on the Keysight website?
Version 1.1.1-1.0.2-1.05 from 26 Feb 2018

Bug Fixes
• Fixed knob inconsistency issue
• Fixed store/recall issues
• Fixed relay state after power cycle (E3631A Persona Mode)
• Fixed incorrect configuration on series mode
• Fixed unit hung issues

Enhancements
• Added Multiple Languages help (French, German, Japanese, Korean, Chinese, and Russian)
• Enhanced SCPI datalog fetch command parameter to support up to 65536
• Enhanced front panel to run LIST when trigger source set to IO

[bitseeker]

Hmm, nothing about the excessive power consumption when "off."

[nctnico]

And the spike on channel 1 when the mains power is connected hasn't been fixed either  I've still got the box!

[LaurentR]

Got one of these puppies yesterday (E36313A), updated firmware, started using it and...

I noticed that the Series mode current is off by (exactly) 10% under some circumstances.

E.g. I set (any sufficient voltage), current = 1.000A, the supply reads back 1.000A and my DMM reads back 1.100A.
I can set current to pretty much any value and it's exactly 10% off.

I did some more experiments with different meters in different modes (e.g. the 34465A exhibits the problem on the 10A range and not the 3A range) and long wires in series... and it seems that it's 10% off under a certain burden voltage (experimentally 200mV) and then gradually becomes correct above that burden voltage.

Has this already been reported? Is anyone else seeing this?

I did notice this line in the firmware notes "Fixed incorrect configuration on series mode". I am wondering if it's related.

It's possible they are compensating for something like internal relay or trace resistance in sw and the sw is confused by the very low voltage.

[nctnico]

I'm pretty sure it is oscillating. Probably a design trade-off to measure low currents which prohibits using large electrolytics on the output due to their large and time dependant leakage current.

Edit: just tried it myself. No oscillations but it only seems to occur when you connect a dead short in series mode.

[LaurentR]

It turns out that the set Voltage (!) is what makes the issue appear or disappear as shown on the video below.

Basically, if the set voltage is below a small multiplier (3-4 in this case) of the burden voltage, it's all fine. But if the set voltage is higher, the burden voltage increases and so does the current until current reaches 1.1x, then both stabilize. In the video, I go up then back down in voltage. As the set voltage crosses 2.5-3V, the transition occurs.
The top DMM is showing actual voltage (matches the power supply's voltage readout and the bottom DMM is showing current).

[nctnico]

Daniel!!!!!!   

[LaurentR]

Finally, the Matlab version:

Setup:
* E36313A (1.1.1 FW) in series mode. Current set to 1A. Voltage sweep from 0V to 3.5V.
* One DMM (3446XA) in DC current mode, fixed 3A range, directly plugged to the output of the PSU, as documented for the series mode (left terminal of Ch2 and right terminal of Ch3).
* One DMM (3446XA) in DC voltage mode, fixed 1V range, plugged to the same terminals.

What we see:
* 0-0.4V: CV mode. Readout voltage similar on PSU and DMM and ~= Set Voltage on PSU. Readout current similar on PSU and DMM and proportional to Set Voltage. All good.
* 0.4-1.3V: CC mode. Readout voltage constant and similar on PSU and DMM. Readout current similar on PSU and DMM and ~= 1A. All good.
* 1.3-1.6V: mode. Readout voltages agree but resume climbing. PSU readout current showing stable ~= 1A while actual current on DMM goes up.
* 1.6+V:  CC mode. Everybody is constant again. Voltages agree but currents don't. PSU current claims ~= 1A while DMM ~= 1.1A. Voltages agree with DMM current, definitely not with PSU readout current.

I tried at 2A and it's pretty much the same with an inflection zone ~2.4-2.8V and at 0.5A, the zone is ~0.7-1.1V.
The inflection zone also changes with the burden voltage. With Set Current to 1A and comparing the 10A input of the 3446XA vs. the 3A input in 3A range, the burden voltage is ~0.058V vs 0.425V and the inflection zone is 0.59-0.85V vs. 1.32-1.66V.

I have an email out to Keysight. I'll keep everybody posted on this. I'd still be interested to see if somebody can reproduce it or if this is just my unit.

[nctnico]

It seems my unit does the same. I'll check to see if it matches your values later today.

[HighVoltage]

So far I had not used Series or Parallel mode on my E36312A.
It seems my unit behaves very strangely, or I do something totally wrong.

When I set mode coupling to SERIES, I get the following:
- On the display it shows that Series Mode is turned on between CH2 and CH3
- When I turn all channels ON, only CH1 and CH2 light up as ON
- CH3 light is OFF
- CH3 carries 1V (set to 1V) (hmm ... weird)
- CH2 carries 1V (set to 1V)
- CH1 carries 1V (set to 1V)
- Output between CH2 and CH3 carries 0V
- Output between CH1 and CH2 carries 0 V
- If I add a series cable connection between CH1 and CH2 I get 2V on the output, although CH1 is set to 1V and CH2 is set to 2V

Hmm, big flaw it seems
Let me update to the latest FW and test again.

 

[HighVoltage]

OK, I should have done the FW update first and the series mode testing.
FW update was a success.
The series mode is working now.

However, I can confirm the strange increase from 1.0A to 1.1A by just increasing the output set voltage of the PSU.

Voltage set to 1V and current set to 1A results in 1A measured with the 34465A.
Increase set voltage slowly and at about 1.35V the current starts to increase.
At about 1.7V set voltage, the current has increased to 1.1A (10% error)

[TiN]

Mine does same, I had to increase 1.6V, current goes up to 1.0995A (K2002).
Same happens with lower Ilim (0.1A will give 10% limit error = 0.110A) when voltage set over 0.534V.

[HighVoltage]

One partial workaround ...

In series mode between CH2 and CH3, if you only use the output of CH2 and connect noting to CH3, the current will not increase by 10%.
But you are limited to 25V, so it defeats the purpose of series mode.
If you want above 25V output, you need to hook your cables up between CH2 and CH3 and the current may increase by 10% in all settings I tested.

Well, I would assume that these series mode inconsistencies can all be fixed by firmware and they are not hardware related.


Would be nice to get a statement from Keysight!

[rsjsouza]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

As expected channel 1 still has a spike for several hundred ms when mains are applied: 7.7V when loaded with 820 Ohm and 12A when shorted.

Nico, the spike you are getting is coming when you power on the power supply or when you turn on the channel?

I tried to reproduce this on my E36312A (still with the original FW) and could not see anything on the output when the PS is turned on (the channel output is off anyways)

When switching on channel 1 with a load of 500\$\Omega\$ on 6V, I got the following:


When switching on channel 2 with the same load, the results were similar:


When switching on either channel 2 or 3 with the same load but with 25.75V, I got the following:

[nctnico]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

As expected channel 1 still has a spike for several hundred ms when mains are applied: 7.7V when loaded with 820 Ohm and 12A when shorted.

Nico, the spike you are getting is coming when you power on the power supply or when you turn on the channel?

The spike occurs when you plug the mains in.

[rsjsouza]

I ordered a E36313A as well and delivery is confirmed Januari the 26st. Perhaps this model is produced in lower quantities or more popular than expected.

Mine arrived today so that is slightly ahead of schedule. I'm going to update the firmware first and do some tests.

As expected channel 1 still has a spike for several hundred ms when mains are applied: 7.7V when loaded with 820 Ohm and 12A when shorted.

Nico, the spike you are getting is coming when you power on the power supply or when you turn on the channel?

The spike occurs when you plug the mains in.

Wow... Ok. I don't think this can be fixed by firmware - the standby circuit is probably taking too long to kick in when powered.

[LaurentR]

I got some basic answer from Keysight, but it'll take some more back and forth. I have pointed them to the thread.
Apparently, the fw change on series mode was related to OCP, not to anything like this.

Main issue update

I put the electronic load into service (CR mode) to put some more variety of loads on the supply and the issue is present all over up to 50V.

Basically, in CC mode, it seems that whenever the output voltage is less than approximately half the Set Voltage on the PSU, the PSU "silently" outputs 10% more current. That's a pretty broken CC mode.


"Manual" series mode

While at it, I tried the "manual" series mode as suggested by HighVoltage, i.e. connecting Ch2 and Ch3 externally and setting them to the same Set Voltage/Current (I also enabled tracking mode, but it shouldn't have any impact).

I don't see the issue, but Ch3 insists on being a drain (negative voltage). All voltages (including the negative one on Ch3) are confirmed by an external DMM.
This looks weird and I don't know if this is normal/expected behavior (I was expecting Ch2 and Ch3 to be more symmetric than this) and if it may be related to the main issue. At least, it's functionally correct overall.
I put the electronic load on it and Ch3 stays at -200mV all the way until Ch2 gets to 25V and switches to CV mode. Then Ch3 "takes overs" and voltage starts increasing from -200mV all the way to 25V, then it switches to CV mode...

Screen capture of the "manual" series mode (i.e. externally hooked up, same Set Voltage/Current) at the extreme where Ch2 has switched to CV mode and Ch3 is still lingering in CC mode with a negative voltage (2R4 load):

[bitseeker]

Do you have a tracking ratio set between CH2 and CH3 that isn't 1:1?

[LaurentR]

Do you have a tracking ratio set between CH2 and CH3 that isn't 1:1?

Tracking mode is pretty basic. It just makes the Set Voltage on Ch2 and Ch3 track, nothing else. There is no ratio I can find.
All in all, it's not relevant to the experiment.

[bitseeker]

Ah, I think I just misunderstood the described behavior. I got it now, thanks.

[LaurentR]

Ah, I think I just misunderstood the described behavior. I got it now, thanks.

Np. Your question prompted me to recheck the manual and update the original post to remove the (irrelevant) reference to tracking mode, so it's all for the best.

[Andrew]

Keysight document "Keysight Technologies - Distribution Products Catalog" for March 2018:

http://literature.cdn.keysight.com/litweb/pdf/5991-4833ENDI.pdf

Page 34 would appear to indicate the E36300A series will be replaced with a E36300B series. Possibly a hardware update?

[LaurentR]

Keysight document "Keysight Technologies - Distribution Products Catalog" for March 2018:

http://literature.cdn.keysight.com/litweb/pdf/5991-4833ENDI.pdf

Page 34 would appear to indicate the E36300A series will be replaced with a E36300B series. Possibly a hardware update?

Good catch. The specs don't seem to be any different and the picture on the catalog is that of a A version, so I am not sure what the differences are (maybe a fix to the startup spikes and the not-really-off issues).

[LaurentR]

On te series mode issue, Keysight has reproduced the issue in the US, then I got a "We are aware of this and R&D is currently working on it."

I have asked if this is a firmware fix or a E36300B fix and will report back if they commit to an answer.

[bitseeker]

It's good to hear that there's a "B" version in the works. From the findings thus far, it seems the "A" version hasn't been quite where it should.

[nctnico]

It's good to hear that there's a "B" version in the works. From the findings thus far, it seems the "A" version hasn't been quite where it should.

If the power on spikes don't get fixed in the A version through a firmware upgrade I expect Keysight to take my A version back and exchange it for a B version (or do an upgrade). It is not a particulary cheap power supply.

[PedroDaGr8]

Keysight document "Keysight Technologies - Distribution Products Catalog" for March 2018:

http://literature.cdn.keysight.com/litweb/pdf/5991-4833ENDI.pdf

Page 34 would appear to indicate the E36300A series will be replaced with a E36300B series. Possibly a hardware update?

Good catch. The specs don't seem to be any different and the picture on the catalog is that of a A version, so I am not sure what the differences are (maybe a fix to the startup spikes and the not-really-off issues).

The E3610x series B version was just released, the spec sheet mainly shows notably reduced ripple under performance specifications (around 50-70% reduction is rms and pk-to-pk for most models). So that leaves me wondering why the B revision, rather than just keeping the same model and tightening the spec.

[bitseeker]

Perhaps some corrections need hardware modification in addition to firmware support. So, the B version could go out now with the corresponding firmware changes to follow.

[LaurentR]

The E3610x series B version was just released, the spec sheet mainly shows notably reduced ripple under performance specifications (around 50-70% reduction is rms and pk-to-pk for most models). So that leaves me wondering why the B revision, rather than just keeping the same model and tightening the spec.

Well, they turned the front panel gray on the E36100, so that's worth a major rev 
They more or less seem to have done the same with the N6705C, which AFAICT is a N6705B, except gray and RoHS compliant.

Now, for the E36300B, I just got some feedback from Keysight: "We checked with marketing, and the document that shows the E36300"B"'s is in error. We recently came out with "B" versions of our small E36100 family, but not the 300's."

[bitseeker]

Oopsie!

[rsjsouza]

Main issue update
(...)
Basically, in CC mode, it seems that whenever the output voltage is less than approximately half the Set Voltage on the PSU, the PSU "silently" outputs 10% more current. That's a pretty broken CC mode.
"Manual" series mode

Interestingly enough, I tested this earlier this morning and found out that my E36312A goes beyond its ratings: it puts out 1.1A in the output, while the PS is rated for 1A only.

I followed your method and I am using the latest firmware (updated two days ago).

[HighVoltage]

Interestingly enough, I tested this earlier this morning and found out that my E36312A goes beyond its ratings: it puts out 1.1A in the output, while the PS is rated for 1A only.

I followed your method and I am using the latest firmware (updated two days ago).

Yes, it seems all the E3631xA units have this problem with about 10% higher current output under some conditions. Hopefully Keysight can fix this with a FW update

[bitseeker]

rsjsouza, are you referring to the incorrect output as compared to the display or that the supply can go beyond its maximum rating? I assumed the latter, but it sounds like HighVoltage assumed the former.

I think all my HPAK power supplies, covering several different decades, are able to go over their range. I've seen in some of the manuals where it's documented as being a feature, but accuracy is not guaranteed when going out that far.

[LaurentR]

bitseeker, the E36300A cannot be programmed higher than they are specced, either through the front panel or through SCPI, so it I expect it is the former.

[rsjsouza]

Bitseeker, both. I see the behaviour that LaurentR is seeing: +10% of measured current output when the set output voltage is increased above a specific value when in CC mode. That goes up to 1A set but 1.1A measured in its output.

[bitseeker]

I see, so it is the aforementioned bug. Thanks for the clarification.

[LaurentR]

On the series mode issue, Keysight has reproduced the issue in the US, then I got a "We are aware of this and R&D is currently working on it."

I got an update from Keysight today:
"We will have this fixed through firmware upgrade. The new firmware is expected to be available at K.com by early May."

Good news!

[cowana]

That's good to know a new firmware update is on it's way. Hopefully it will also include a few improvements to make the UI slightly more intuitive (such as better rotary encoder acceleration).

[TomS_]

It has been some time since an updated was posted to this thread, I wonder if anyone has any news on fixes, current state, etc?

Im very quickly coming in to the market for a bench power supply, and this was looking like a reeeallly nice supply, but with all of the bugs etc I feel like Im falling back to the Rigol DP832 option.

I did have a read through the thread and there seemed to be good traction from Keysights end in response to the reported issues, so Im hoping that it is now becoming a top notch unit!

Thanks
Tom

[HighVoltage]

I am using my E36312A on a regular basis and it works very well. Since I know about the issues, I just don't use the instrument in those areas. I am sure Keysight will fix the issues over time with Firmware updates.

[rsjsouza]

Same here; the power supply is a top performer and the bugs reported are not critical to me.

[Omicron]

I bought a E36311A early on as it seemed perfect in terms of features and performance. I trusted the Keysight reputation. I have a main power switch on my bench that disconnects all my equipment from mains. I turn this off after work each day. Needless to say I got bit by the voltage spike issue. It didn't destroy the board I was working on fortunatly, but it did almost cause me a heart attack when I saw the LEDs on that (expensive) board flash when I powered up my bench! This power supply has been banned from my lab ever since and I wouldn't recommend it to anyone, no matter how good it is in other respects. I simply don't trust it. If the issue can be fixed with a firmware update then they are surely taking their sweet time doing it. My guess is it can't be fixed in software and so they are keeping quiet. It'll take a lot before I buy another Keysight product.

[nctnico]

With the most recent firmware only channel 1 is affected. I made it a habit to disconnect everything from channel 1.

[HighVoltage]

Many many years ago, I was hit with a "crowbar issue" of an Agilent power supply that was killed and learned the hard way to always remove any connections from it, before doing a power cycle. So, it has become also a habit for me, to never leave anything connected.

[Omicron]

In my opinion it is an unforgivable flaw. Especially for a company with the pedigree of Keysight. A power supply that is turned off should never be putting out energetic spikes on any of its outputs. If they had any decency they would recall these units. I bought this device but I refuse to defend it in any way.

[rsjsouza]

My guess is it can't be fixed in software and so they are keeping quiet.

That is my guess as well.

Many many years ago, I was hit with a "crowbar issue" of an Agilent power supply that was killed and learned the hard way to always remove any connections from it, before doing a power cycle. So, it has become also a habit for me, to never leave anything connected.

Despite I was never hit with such problem with a lab power supply, I was hit enough times with other types of supplies that I never take any soft switch systems for granted - either it has a mechanical disconnect (a.k.a. clunking switch) or I simply don't trust it.

[nctnico]

In my opinion it is an unforgivable flaw. Especially for a company with the pedigree of Keysight. A power supply that is turned off should never be putting out energetic spikes on any of its outputs. If they had any decency they would recall these units. I bought this device but I refuse to defend it in any way.

I agree that if Keysight can't fix this with a firmware upgrade they have to do a recall. Unfortunately even the A brands seem to push too hard to get gear on the market nowadays.

[LaurentR]

Keysight just published a new firmware that is supposed to fix the series-mode current issue I reported a while back. The release notes contain no other fixes. I haven't had a chance to try the new fw, but I wonder if it addresses some of the other pending issues.

https://www.keysight.com/main/software.jspx?ckey=2880097&lc=eng&cc=US&nid=-35673.1215253&id=2880097

[nctnico]

Unfortunately this update doesn't fix the start-up spike on channel one 

[apblog]

Have you guys seen this yet?  It looks like Keysight is aware of the power-on glitch problem and has a fix:

http://literature.cdn.keysight.com/litweb/pdf/E36313A-01.pdf

If I'm reading that right, you can either get a free replacement or possibly just a free repair until May 1 2019.

I've got a new one arriving here in a few days -- with a "good" serial number.

Last week, my Keysight dealer told me that they had sent all of their stock back to keysight in early May, presumably to be fixed.  He assured me that I'll be getting a unit that does not have the problem.

[nctnico]

Thanks! I'm going to book a short trip for my E36313A!

[sdouble]

I guess that the E36312A is also affected by that issue, right ?

[apblog]

I guess that the E36312A is also affected by that issue, right ?

Looks like it.

Here are the service notes for the E36311A and E36312A:

http://literature.cdn.keysight.com/litweb/pdf/E36311A-01.pdf

http://literature.cdn.keysight.com/litweb/pdf/E36312A-01.pdf

[apblog]

So, I just wanted to post an update.

My new E36313A is here, and it's great, I love it.     It's hard to get excited about a nice power supply, but it's a lot like having a good vise -- it's boring but it makes everything else easier.

They've mostly, but not entirely, fixed the voltage spike that occurs when you plug it in.

It still has a +/- 1.5 volt (max) glitch when you plug it in.  But it's only nanoseconds long instead of milliseconds as some people were reporting previously.   Little enough energy and low enough voltage to totally not be a problem for me.

Also I'm not seeing any sign of the UI bugs that people were reporting.

There are two features though that I would really like to have.

1. The ability to turn on/off the outputs simultaneously by pressing two buttons at once.  It turns out if you press two buttons at once it doesn't recognize either of them.  It does beep though, just to taunt you. 

2. The abiliity to run the logging chart in continuous mode, so you can just keep it running and kind of keep an eye on it or look at it really quick if your board does something odd.

I love the high-res (1 mA) current readout.  It's great for keeping an eye on power consumption as I bring up the various peripherals on the board. 

[adamgreig]

I emailed Keysight UK about the service note and they agreed to handle it under warranty . They collected my E36312s and replaced them with new/refurb units with new serial numbers. Took about 2 weeks from collection to getting new ones, posted from Germany. Annoyingly they didn't post them in the original packaging, just in a box with some expanding foam bags, so while they were well packed it's a real pain to repack and the box won't hold the cardboard accessories box any more  I suggest sending yours in disposable boxes rather than the originals!

Anyway the power-up transient is hugely improved; I see about 6Vpp for 200ns or so into a 2R load, and roughly similar into 50R. With no load there's a bunch more high frequency ringing (around 30MHz?) but still only for a couple hundred nanoseconds. So that's still 2W into my load but only 0.4µJ... probably ok! Before we were getting DC 8V for 300ms so this is a lot better. Some scope captures: https://imgur.com/a/ucG1sRv

Internally the power PCBs are all the same revision, 005 for the mains /1ch PCB and 003 for the top board (other two channels), I couldn't check the front board but it looks identical too, so maybe the fix is a greenwire or component change rather than a new PCB. Not sure.

Standby power is still 11W, and barely goes up to 12.5W when turned on. Can't win everything!

[LaurentR]

I emailed Keysight UK about the service note and they agreed to handle it under warranty . They collected my E36312s and replaced them with new/refurb units with new serial numbers. Took about 2 weeks from collection to getting new ones, posted from Germany.

I sent mine in to Santa Rosa (I am in the US) last week, and much to my surprise, the unit was sent to Germany with a message "Received on 06/21/2018. In progress (Expected completion on 07/24/2018) Service performed by Boeblingen Germany Hub".

Since I thought this was going to be a quick exchange, I asked what was happening and got this: "This does need to go overseas to be evaluated first then we will supply the refurbished unit."

[adamgreig]

Since I thought this was going to be a quick exchange, I asked what was happening and got this: "This does need to go overseas to be evaluated first then we will supply the refurbished unit."

I wonder what they need to evaluate, given it's their service note saying all units are affected! Mine was estimated completion 29th June but actually got posted on the 25th.

[pe1oxp]

Just curious, how do they swap the power supplies? Do you get a 'new' one ore just one out of the poo which is modified?
This because mine are almost 'new in box' and won't get a replacement with a bunch of scratches

[LaurentR]

Just curious, how do they swap the power supplies? Do you get a 'new' one ore just one out of the poo which is modified?
This because mine are almost 'new in box' and won't get a replacement with a bunch of scratches

I got mine back this week. I got a new unit (I had asked for it - not sure if that's std). Funnily enough, it didn't come with a box at all, it was brought by a Keysight-branded courier as is (they are not joking when telling you to not send any accessories - even the terminal blocks). My wife had no idea what it was and I found it laying on the kitchen table, side handle up 

[cowana]

(they are not joking when telling you to not send any accessories - even the terminal blocks)

Strangely my replacement came with the three sets of terminals attached (I hadn't sent in any on the unit I returned). It looks to be brand new and shows no signs of use - maybe terminal blocks get attached at some stage during calibration?

Return shipping was in a giant cardboard box, with those bags of expanding foam keeping it safely in the middle of the box.

[nctnico]

(they are not joking when telling you to not send any accessories - even the terminal blocks)

Strangely my replacement came with the three sets of terminals attached (I hadn't sent in any on the unit I returned). It looks to be brand new and shows no signs of use - maybe terminal blocks get attached at some stage during calibration?

Return shipping was in a giant cardboard box, with those bags of expanding foam keeping it safely in the middle of the box.

Same here. I'm not quite happy with the way it got shipped back. I shipped mine back in the original box & packaging and was expecting to get it back the same way. I send the terminals back as well but the unit I received came with the terminal blocks so the people at Keysight have been paying attention.

[HighVoltage]

I shipped my E36312A in the original box today to Keysight Germany.
Looking forward, to how it will come back. Hopefully in the original box.

[bitseeker]

Just curious, how do they swap the power supplies? Do you get a 'new' one ore just one out of the poo which is modified?
This because mine are almost 'new in box' and won't get a replacement with a bunch of scratches

I got mine back this week. I got a new unit (I had asked for it - not sure if that's std). Funnily enough, it didn't come with a box at all, it was brought by a Keysight-branded courier as is (they are not joking when telling you to not send any accessories - even the terminal blocks). My wife had no idea what it was and I found it laying on the kitchen table, side handle up 

Yeah, if you're within range of one of their couriers or shuttles, they'll hand deliver a replacement. The same thing happened to me with a DMM that was defective. I shipped the bad one to them. Some time later, they scheduled a drop date/time and the guy who arrived just handed me the replacement DMM (no box or accessories) with the usual big yellow envelope containing its calibration certificate. It looked new, but I felt it was a little odd that the meter didn't come in some kind of container. Great service, though.

[capt bullshot]

Did anyone make a before-after comparison yet?
Not what the transient looks like, but in terms of what gets modified / replaced, or is there any component level instruction for the mod available, as with the "good old stuff"?

[pe1oxp]

Just curious, how do they swap the power supplies? Do you get a 'new' one ore just one out of the poo which is modified?
This because mine are almost 'new in box' and won't get a replacement with a bunch of scratches

I got mine back this week. I got a new unit (I had asked for it - not sure if that's std). Funnily enough, it didn't come with a box at all, it was brought by a Keysight-branded courier as is (they are not joking when telling you to not send any accessories - even the terminal blocks). My wife had no idea what it was and I found it laying on the kitchen table, side handle up 

Thanks for your reply. Will look for another box before I ship the power supply.  So I can keep the original box for calibration of repair.
Hopefully they will ship it back in a box otherwise it can be damaged at the local bookshop before i can pick it up

[TiN]

I've sent mine over a month ago, and still waiting. Supposed to be done 7/16 but there is "parts shortage" and no ETA. 

[rsjsouza]

The whole process for me is taking more than a month, with the regular service being done in Germany. I am supposed to receive it next week. Hopefully they schedule a delivery time if they want to hand it off like others.

Regarding packing: if you have babies or toddlers, the package for bulk quantity of diapers and wipes is a good reasonable solution for most electronics. The power supply could fit in the largest box, but still with not much room for filler material. I then remembered I had purchased a large water pump a few weeks earlier and used that to send the PS.

Thr irony: after sending the PS via mail, a few weeks later Keysight sent me an email advertising their delivery program.

[HighVoltage]

I shipped my E36312A on July 30th to Keysight Germany and received a new one today,
7 working days later. Great service, Thank you Keysight!

It was returned in a generic Keysight box, without any accessories.

[rsjsouza]

Mine arrived today. It took a very long time (arrived at Keysight on Jun 28th) and, similarly to TiN, I was notified of a parts shortage.

The power supply was shipped back in a very large Keysight box (larger than the original) with pínk expanding foam that was entirely surrounding the power supply (yes, even the bottom).

The highest peak is quite narrow (40ns) and, at a load of 500\$\Omega\$ it spikes looks like the picture below (16vpp)

[sdouble]

could someone proceed to the same measurement with a higher bandwidth scope ?

[2N3055]

With more than 500 MHz and 4GS/s ? What for? Few centimetres of cable will completely dominate what you see on a screen even at 500MHz..

[nctnico]

With more than 500 MHz and 4GS/s ? What for? Few centimetres of cable will completely dominate what you see on a screen even at 500MHz..

Not just that but what you see on screen is probably due to plugging in the mains and not a power up spike due to the PSU output. It will be very hard to generate such a spike across the output capacitors of a typical power supply.

[rsjsouza]

One detail I forgot to mention is that the peak voltage varied a lot (the maximum I got was 21Vpp) but the waveform was quite consistent. The oscilloscope is in full BW mode (500MHz, as Sinisa mentioned).

This is the 6V output, BTW. I don't have a measurement of the signal before the repair.

Other aspects that were mentioned by others: the PS still draws 10W (!) in standby and the backlight still seems to be turned on all the time (there is a faint glow on the screen).

[nctnico]

You can try to measure the other outputs. I think you'll see the same signal.

[2N3055]

I think nctnico might be right. It  seems to be some kind of inductive spike from sudden switch on of transformer. I could replicate a version of it on 3 different linear PSU. Maybe some version of controlled phase switch on would be useful. Or it is practical short circuit on secondary (elkos after diode bridge)  that makes core go into saturation and makes some nonlinear kind of spike...

[bitseeker]

Other aspects that were mentioned by others: the PS still draws 10W (!) in standby and the backlight still seems to be turned on all the time (there is a faint glow on the screen).

Is the cooling fan still running like it was before?

I'm still puzzled by that vampire power draw. It's not like the thing has an OCXO in it. Does it boot faster from standby and, hence, needs 10W to keep it ready to turn on?

[sdouble]

I really suffered from the power on spike  from all 36312A that I bought for the lab.
I used them to power charge sensitive preamps. They killed a large number of the preamps, actually their input linear regulator (LT3042).
I would like to know how much of the initial issue remains : could I safely power my preamps with the modified 36312A.

[rsjsouza]

Some additional waveforms: 500Mhz Peakdetect mode in the same 500\$\Omega\$ load. Various runs were done that showed the same basic waveforms but with varying peaks.

Channel 1: the highest peak


Channel 2: the longest train of transients




Channel 3: the quietest


At any rate, the transient train does not seem to extend for much more than 300ns, which is quite the improvement over previous reports in the hundreds of ms. From these waveforms, the worst case would be 34V applied during all 300ns on the specified load, which would yield a total energy fo 690nJ.

Other aspects that were mentioned by others: the PS still draws 10W (!) in standby and the backlight still seems to be turned on all the time (there is a faint glow on the screen).

Is the cooling fan still running like it was before?

I'm still puzzled by that vampire power draw. It's not like the thing has an OCXO in it. Does it boot faster from standby and, hence, needs 10W to keep it ready to turn on?

The cooling fan runs all the time.

[nctnico]

I'll do some tests myself when I can. I'm pretty sure these transients are induced into the ground loop between the PSU and the oscilloscope and are not actually present on the outputs.

[TheSteve]

Someone perform the same tests with a handheld/battery powered/fully isolated scope.

[nctnico]

Someone perform the same tests with a handheld/battery powered/fully isolated scope.

I was thinking about using a differential probe but I also have a MicSig tablet scope which is battery powered. It will probably be the end of the week when I can do some testing.

[bitseeker]

That'll be interesting to see. Thanks, nctnico.

[rsjsouza]

You guys are onto something. I don't have a differential probe, but I did some measurements with the grounded oscilloscope at an outlet further away from the power supply. The amplitude is reduced in Ch1, despite some oscillation is still seen in Ch3 (grounded at the load). The picture below shows both channels plus Ch1-Ch3. All previous parameters are applicable.

Another interesting detail: if I switch the power supply continuously, the spike is reduced - perhaps some Y capacitors become a bit charged and dampen the spike.

[2N3055]

You guys are onto something. I don't have a differential probe, but I did some measurements with the grounded oscilloscope at an outlet further away from the power supply. The amplitude is reduced in Ch1, despite some oscillation is still seen in Ch3 (grounded at the load). The picture below shows both channels plus Ch1-Ch3. All previous parameters are applicable.

Another interesting detail: if I switch the power supply continuously, the spike is reduced - perhaps some Y capacitors become a bit charged and dampen the spike.

As I said, it is connected to large switch-on current transient, which is combined from current to establish magnetic field in a transformer, combined with virtual short circuit on secondary (made from bridge rectifier and large, empty capacitors). Probably a soft start circuit  would make it much better.

[rsjsouza]

Yes, I agree. The large switch-on current transient is most certainly the main transformer itself being connected at all times to the mains. The reason for my suspicion is that in standby it consumes 10W (17VA) and when it is turned on it increases by about 1W (11W / 18VA) - no load. The power factor is what you would expect of a transformer.

When I float the PS and use the two oscilloscope channels to measure the output, the waveform is quite similar to the first ones I have sent.

[pe1oxp]

Just curious, how do they swap the power supplies? Do you get a 'new' one ore just one out of the poo which is modified?
This because mine are almost 'new in box' and won't get a replacement with a bunch of scratches

I got mine back this week. I got a new unit (I had asked for it - not sure if that's std). Funnily enough, it didn't come with a box at all, it was brought by a Keysight-branded courier as is (they are not joking when telling you to not send any accessories - even the terminal blocks). My wife had no idea what it was and I found it laying on the kitchen table, side handle up 

Thanks for your reply. Will look for another box before I ship the power supply.  So I can keep the original box for calibration of repair.
Hopefully they will ship it back in a box otherwise it can be damaged at the local bookshop before i can pick it up

Keysight picked up my power supply at August 14, no packaging needed, al done by there own courier. Received the new one back yesterday (August 29) in a big carton box brought by GLS.
So it took 2 weeks to swap the power supply including full calibration of the new one (ISO17025)

[nctnico]

I'll do some tests myself when I can. I'm pretty sure these transients are induced into the ground loop between the PSU and the oscilloscope and are not actually present on the outputs.

I finally did some testing. The transients are definitely ground loop related. I also tried a different PSU which has a relay at the output and I get similar spikes when the mains are switched on. All in all I have to conclude that Keysight has fixed the power on spikes on all channels with the hardware modification / newer models 

[nctnico]

BTW I found a good use for the 4th output channel. Currently I'm developing a USB powered gadget and the front USB connector is ideal to get 5V from 

[apblog]

BTW I found a good use for the 4th output channel. Currently I'm developing a USB powered gadget and the front USB connector is ideal to get 5V from 

Very creative!    I hadn’t even though of using that for power.  Mine gives about 600ma before the voltage starts to sag.

[HighVoltage]

600 mA is not bad, even enough to slowly charge the smartphone.

To Keysight:
Why not add a display option for the USB output details to test USB devices.

[plurn]

Have not noticed it mentioned elsewhere yet but I have not really looked extensively. There is an 02 service note for E36312A and E36313A relating to "Compliance to EMC IEC61000-4-3 standard requires a ferrite core":

http://literature.cdn.keysight.com/litweb/pdf/E36312A-02.pdf
http://literature.cdn.keysight.com/litweb/pdf/E36313A-02.pdf

E36311A does not seem to have the same service note as of this time. Perhaps it is not applicable to this unit?
https://servicenotes.literature.keysight.com/litapp/SearchSN.do?method=openExternalSNSearch&prodNum=E36311A

free customer installable kit to address the issue.

[Andrew]

Spotted a new IVI driver for this series of power supply which also adds support for new models...

2019-04-30 - 1.5.0.0 - Added SCPIs and model support of E36231A, E36232A, E36233A and E36234A.

The arrival of summer (northern hemisphere) signalling the start of the tech-show season and the prospect of new models.

Add link: https://www.keysight.com/main/software.jspx?ckey=1669314&lc=eng&cc=US

[JxR]

Spotted a new IVI driver for this series of power supply which also adds support for new models...

2019-04-30 - 1.5.0.0 - Added SCPIs and model support of E36231A, E36232A, E36233A and E36234A.

The arrival of summer (northern hemisphere) signalling the start of the tech-show season and the prospect of new models.

Add link: https://www.keysight.com/main/software.jspx?ckey=1669314&lc=eng&cc=US

Here is the data sheet I found on those if your interested.  I have no info on when they will actually be available.

• E36231A: Autoranging DC Power Supply 30V, 20A, 200W
• E36232A: Autoranging DC Power Supply 60V, 10A, 200W
• E36233A: Dual Output Autoranging DC Power Supply 30V, 20A, 400W
• E36234A: Dual Output Autoranging DC Power Supply 60V, 10A, 400W

[JxR]

For the owners that went through the repair/replacement process: Are you comfortable enough with the transients when mains is applied to leave a DUT connected now?

I had a DP832 for a few years that I finally got fed up with for that exact issue (large transients when mains was applied).  I'm not willing to deal with something like that anymore.  Also, I would have to put a switch between the unit and the mains due to the power draw in standby(off).

They are building a lot of new homes around me, and since that started, its not too uncommon for minor power interruptions now and again.  A couple things died connected to the DP832 during one of those quick power interruptions.  Anyways, just wanted to make sure everyone is happy and comfortable with the unit now.  I also may end up holding out for one of the higher power units, but I'm expecting them to be similar in operation. 

Thanks.

[rsjsouza]

For the owners that went through the repair/replacement process: Are you comfortable enough with the transients when mains is applied to leave a DUT connected now?

It is not an issue for me. Earlier in this thread there are some waveforms that were gathered before and after the repair.

[nctnico]

For the owners that went through the repair/replacement process: Are you comfortable enough with the transients when mains is applied to leave a DUT connected now?

The power-up transients are completely gone after the fix.

[JxR]

Thanks everyone for confirming that the mains power issue has been put to rest.

I didn't keep it for long, though, as I don't need the power, and I have a very tight benchtop space, so I ended up with a PXI-based SMU.
But for a standalone unit, I highly recommend E36313A.

Thanks for the recommendation.  I love your PXI setup, it looks great!  I find myself dragging equipment back and forth to my university, so a single box with that much functionality would be incredible.  Maybe one day...

[apblog]

I have one that was sent back and repaired by the dealer shortly before I bought it.  It's fine.

If you hook up a scope and power it on, you might a small/short transient, but we're talking about nanoseconds and a volt or two.  Some people here figured out that it the post-fix transient we were seeing was being conducted through the AC and (at least mostly) wasn't real.  I buy that explanation.

I am very comfortable leaving my expensive prototypes hooked up to this supply.   

It does draw current when turned off though.  I keep mine on a power strip.

[rsjsouza]

It does draw current when turned off though.  I keep mine on a power strip.

Yes, one of the remaining biggest annoyances to me is the backlight that never seems to be turned off (something also confirmed by another user early on this thread as well).

I initially thought that was the illumination of the standby LED, but the light is too uniform and different in color.

[bitseeker]

Who designs these things?

[apblog]

Who designs these things?

I have wondered if the embedded portions of this supply were designed by inexperienced engineers.

The fact that you can't press two channel buttons at once, to simultaneously turn on or off multiple channels, is somewhat annoying. 

And when you press two buttons at once, the unit still beeps.

Clearly the beeper is tied to the physical button press and is not an actual acknowledgement of something happening, as it should be.

The multi-press thing is either poor programming or the front panel keyboard is just a resistor for each button, all being sensed by the same a/d line.

And the initial, now fixed, problems with encoder data entry were really beneath a company like Keysight.

On the whole though, I am very happy with this supply.

[apblog]

But while I'm complaining, let's not forget about the logging features.

The logging stops when you fill up the small memory buffer; you can't just stream your log to a file on the USB stick.

And it would be immensely useful to show the chart of voltage/current data at all times, so you can just glance at it while testing your firmware or when there has been some kind of failure.  But the chart stops when the log stops.

What would really great is if it logged to a circular buffer, and you could press a button that would dump the last X seconds to an incrementally numbered file on a usb stick.

The above  features are just firmware changes.  And they would add a ton of value to the unit.

[bitseeker]

What would really great is if it logged to a circular buffer, and you could press a button that would dump the last X seconds to an incrementally numbered file on a usb stick.

I like that idea.

[JxR]

I think my dream power supply is a collaboration by Keysight, Keithley, and R&S. With all of the best from each company and none of their individual shortcomings.

Keithley: metering, graphing, logging, and measurement tools
Keysight: electronic parallel and serial, low noise, desktop software, support structure
R&S: hard-off power button, front panel sense, identical rails, web based control

Sure there is a ton of things I'm leaving out in my list.  Hopefully the new models Keysight has coming out will bring some additional firmware enhancements that all the models can benefit from.

[nctnico]

Who designs these things?

The fact that you can't press two channel buttons at once, to simultaneously turn on or off multiple channels, is somewhat annoying. 

There is a all channels on/off button and IIRC you can program this to switch on/off a combination of channels.

[thanasisk]

How is the web based control on the keysight?

Also did you find  the logging feature any useful ? Does it do any sort of averaging or is it instantaneous? Also what is the min time step/offset?

[capt bullshot]

Also did you find  the logging feature any useful ?

I did some "tricks" using the advanced features:
http://wunderkis.de/E36312A/index.html

Anyway, for regular use these features are too cumbersome (at least to me).

Does it do any sort of averaging or is it instantaneous? Also what is the min time step/offset?

Can't tell anymore, guess you'll have to read the manual

[rsjsouza]

How is the web based control on the keysight?

Also did you find  the logging feature any useful ? Does it do any sort of averaging or is it instantaneous? Also what is the min time step/offset?

I used Keysight's software only briefly, but it worked very well.

To me the interface of the power supply itself is quite good, so I didn't see the need to invest in the software.

The logging is very useful to me and I used to capture battery charge curves. I don't recall averaging being implemented in the supply. It can save all data in .csv format to a pendrive, so Excel or other spreadsheet software can manipulate data quite nicely.

The sample interval goes from 200ms to 60s and the supply nicely calculates the time duration depending on the sample interval, the different collection of logged information per channel (P, V, A) and the memory available.

[thanasisk]

Also did you find  the logging feature any useful ?

I did some "tricks" using the advanced features:
http://wunderkis.de/E36312A/index.html

Anyway, for regular use these features are too cumbersome (at least to me).

Does it do any sort of averaging or is it instantaneous? Also what is the min time step/offset?

Can't tell anymore, guess you'll have to read the manual

Nice tricks on emulating a load, but it indeed take too much work

[thanasisk]

How is the web based control on the keysight?

Also did you find  the logging feature any useful ? Does it do any sort of averaging or is it instantaneous? Also what is the min time step/offset?

I used Keysight's software only briefly, but it worked very well.

To me the interface of the power supply itself is quite good, so I didn't see the need to invest in the software.

The logging is very useful to me and I used to capture battery charge curves. I don't recall averaging being implemented in the supply. It can save all data in .csv format to a pendrive, so Excel or other spreadsheet software can manipulate data quite nicely.

The sample interval goes from 200ms to 60s and the supply nicely calculates the time duration depending on the sample interval, the different collection of logged information per channel (P, V, A) and the memory available.

Thanks for the info . I guess measurements/log performed right on the instrument are more accurate (in time/timestamps) than reading back through lan/pyvisa etc. since they avoid the command overhead and jitter. Although 200ms is not too fast. Have you found this restrictive?

[rsjsouza]

It is restrictive if I want to log fast current transients, but for that I have an oscilloscope.

I simply live with the fact this is a pretty good power supply with a built-in 5Hz DSO - plenty for what I use.

[thanasisk]

Hi, is the (transformer?) hum normal? It appears as soon as the device gets plugged in.

[nctnico]

Hi, is the (transformer?) hum normal? It appears as soon as the device gets plugged in.

My unit also likes to hum.

[rsjsouza]

It is certainly part of the advanced pre-heating circuit that keeps the backlight always on

(My only real pet peeve with this otherwise marvelous bit of kit)

[TheSteve]

Mine is always silent except if I run a heat gun on the same circuit. I get the same buzz/hum on some other HPAK supplies as well with the heat gun.

[Fred27]

It doesn't just hum when plugged in, it draws about 10W on standby. It really does need a proper physical power switch.

[dl1640]

Have 12A, ch2 and ch3 can track with each other, but can't figure out how to configure dual channel with +/- output.

[nctnico]

Have 12A, ch2 and ch3 can track with each other, but can't figure out how to configure dual channel with +/- output.

Connect - and + from ch2 and ch3 and use that as the 0V point.

[rsjsouza]

Have 12A, ch2 and ch3 can track with each other, but can't figure out how to configure dual channel with +/- output.

Connect - and + from ch2 and ch3 and use that as the 0V point.

Also, did you set the output mode to "Series"?

[nctnico]

Have 12A, ch2 and ch3 can track with each other, but can't figure out how to configure dual channel with +/- output.

Connect - and + from ch2 and ch3 and use that as the 0V point.

Also, did you set the output mode to "Series"?

You best use tracking mode for +/- voltage out so you can see the exact voltage. Series mode is likely the same but you'd have to divide the reading by two mentally.

[dl1640]

Thanks for the input!
The "tracking" tracks voltage but not for current
So I put a shorting bar between ch2- and ch3+ and program the 2 chs with keypad under independent mode, now it serves as a +/- supply for some sensor

Mod.:
It would be possible to turn on ch2 and ch3 simultaneously with remote command "OUTP ON,(@2,3)" per user's manual.

[eblake]

This thread mentions several service bulletins (e.g. http://literature.cdn.keysight.com/litweb/pdf/E36313A-01.pdf and http://literature.cdn.keysight.com/litweb/pdf/E36313A-02.pdf

These links are now dead, and I cannot seem to find the documents, even using archive.org. Would anyone care to post the originals?

[TheSteve]

I don't have them and they don't apply to my E36313A, but you can try your serial number:

https://support.keysight.com/KeysightdCX/s/product-lifecycle?language=en_US&c__prodno=E36313A

Enter your serial number, if there are notes related to it they will be displayed.

[DarkLight]

Can you point me to some reference for [lab] power supplies without output capacitors?

[gslick]

This thread mentions several service bulletins (e.g. http://literature.cdn.keysight.com/litweb/pdf/E36313A-01.pdf and http://literature.cdn.keysight.com/litweb/pdf/E36313A-02.pdf

These links are now dead, and I cannot seem to find the documents, even using archive.org. Would anyone care to post the originals?

[alm]

Can you point me to some reference for [lab] power supplies without output capacitors?

I'd look at high-speed power supplies (e.g. Kepco BOP) or for low current, a source measure unit. I can't find any hard data, but I'd think battery simulators (like Keithley 2300 series or Keithley 2281S, or the various Keysight offerings) would also have a pretty low output capacitance due to their sensitive current measurement and high current measurement bandwidth. R&S also has some models that can do this, but I don't know the models from the top of my head.

Designing a power supply without capacitance to be stable across reactive loads is tricky. That's why you'll see guidance about connecting inductive loads in most of their manuals. For example Kepco has models specifically compensated for capacitive or inductive load because the standard model doesn't do so well. The battery simulators will tell you to minimize lead inductance between power supply and DUT. That's why most general-purpose power supplies will have some amount of output capacitance.

[nctnico]

Can you point me to some reference for [lab] power supplies without output capacitors?

For what purpose? If you are afraid about damaging a load when you connect it: you are using a PSU wrong. Disable the output and then connect the load. For most purposes, a capacitor-less PSU will bring more problems that it solves.