Author Topic: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)  (Read 70576 times)

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Offline Ahrenp

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #75 on: December 14, 2017, 09:45:05 pm »
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.
 
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Offline adamgreig

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #76 on: December 15, 2017, 02:40:13 am »
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...

 
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Offline Keysight DanielBogdanoff

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #77 on: December 16, 2017, 05:41:43 am »
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!
 
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Offline bitseeker

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #78 on: December 16, 2017, 05:56:09 am »
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. :-+
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Offline Ahrenp

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #79 on: December 17, 2017, 08:46:18 pm »
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.
« Last Edit: December 17, 2017, 08:59:32 pm by Ahrenp »
 
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #80 on: December 17, 2017, 09:19:15 pm »
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.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline adamgreig

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #81 on: December 17, 2017, 09:34:33 pm »
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.
 
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Offline Dubbie

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #82 on: December 17, 2017, 09:43:02 pm »
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?
 
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #83 on: December 17, 2017, 10:04:29 pm »
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.
« Last Edit: December 17, 2017, 10:09:50 pm by nctnico »
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Offline Dubbie

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #84 on: December 17, 2017, 10:08:50 pm »
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

« Last Edit: December 17, 2017, 10:13:12 pm by Dubbie »
 
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Offline adamgreig

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #85 on: December 17, 2017, 11:14:29 pm »
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.
« Last Edit: December 17, 2017, 11:25:01 pm by adamgreig »
 
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Offline Dubbie

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #86 on: December 17, 2017, 11:49:10 pm »
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:

« Last Edit: December 18, 2017, 12:01:51 am by Dubbie »
 
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Offline Ahrenp

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #87 on: December 18, 2017, 01:33:52 am »
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.
« Last Edit: December 18, 2017, 01:39:05 am by Ahrenp »
 
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Offline HighVoltage

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #88 on: December 18, 2017, 10:50:34 am »
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

« Last Edit: December 19, 2017, 08:35:12 am by HighVoltage »
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Offline HighVoltage

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #89 on: December 18, 2017, 11:42:04 am »
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.
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #90 on: December 18, 2017, 03:47:09 pm »
Keysight has to fix this. What if there is a short interruption in the mains?
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline HighVoltage

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #91 on: December 18, 2017, 05:51:53 pm »
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?
« Last Edit: December 18, 2017, 05:54:36 pm by HighVoltage »
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Offline TheSteve

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #92 on: December 18, 2017, 07:58:57 pm »
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.
VE7FM
 
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #93 on: December 18, 2017, 08:28:42 pm »
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.
« Last Edit: December 18, 2017, 11:52:10 pm by nctnico »
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Offline Keysight DanielBogdanoff

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #94 on: December 19, 2017, 04:43:51 am »
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!
 
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #95 on: December 19, 2017, 07:38:49 am »
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.
« Last Edit: December 19, 2017, 07:46:30 am by nctnico »
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Offline HighVoltage

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #96 on: December 19, 2017, 08:37:06 am »

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

Thank you, Daniel, this is really appreciated!
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Offline Keysight DanielBogdanoff

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #97 on: December 20, 2017, 06:33:13 am »
@nctnico I don't know yet, but I'll let you know!
 
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Offline Andrey_irk

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #98 on: December 20, 2017, 08:23:41 am »
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?

 
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Offline nctnico

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Re: E36300 Series Programmable DC Power Supplies (E36311A, E36312A, E36313A)
« Reply #99 on: December 20, 2017, 11:48:38 pm »
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.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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