New entry-level R&S NGE100 Power Supply Series

[pascal_sweden]

Anybody out here who can do a video review about this new entry-level power supply series from R&S?



https://www.rohde-schwarz.com/us/product/nge100-productstartpage_63493-387267.html?rusprivacypolicy=1

[norks]

Elektor has a video review of the bigger brother HMC8043. The NGE appears to be a stripped down version of this so performance and operation is probably very similar, with fewer features.

https://www.elektormagazine.com/news/elektor-tv-RS-HMC8043-PSU

[rstofer]

It's pretty neat that all 3 channels are floating and all are 0-32V.  You can string them all in series to get 96V.
OTOH, it's odd that there is no chassis ground jack.

[pascal_sweden]

Maybe the ground jack is available on the back connector with screws?

Is the jitter acceptable on switched-mode power supplies these days?
Or is it still better to go for a linear power supply?

[kwass]

Maybe the ground jack is available on the back connector with screws?

Is the jitter acceptable on switched-mode power supplies these days?
Or is it still better to go for a linear power supply?

From what I read on the R&S site, this seems to use a double regulation circuit -- switched mode followed by linear mode.  The new Keysignt low-power supplies work the same way.  It should be a very clean output but they don't state any noise specs on their datasheet. I like the look and functionality on these new R&S supplies, but I hate that they have a cooling fan inside.    I'd like to know what the fan noise is.

[slurry]

Farnell have them in stock, NGE102 and NE103, there is a light price difference but it sure is great to have that third channel sometimes

I have used the HMC8041 which i could not fault and it sure is a brilliant little supply for the money,
a wealth of funcions and LXI and quite good performance, i love the possiblity to see wattage at the same time as voltage and current.

I can not see that this cute NGE-series could be less good?
Datasheet says ripple is less than 1.5mV rms and 2mA rms, what i really look forward to is the arb-funtion, i may have to buy me one of those supplies...

[ebclr]

It's amazing call a USD 890 power supply entry Level

I would imagine what the Top Layer Level will be a million?

[norks]

It's amazing call a USD 890 power supply entry Level

I would imagine what the Top Layer Level will be a million?

They use the same language around their new oscilloscope and spectrum analyzer in the "value instruments" class, which are equally as pricey from the hobbyist point of view. They're competing with the likes of keysight and tektronix. Whether you think they deserve to be in that class is your prerogative. I think they're marketing towards educational institutions, where tek has long had strong presence.

[jpb]

The other thing that is missing, compared to the 8043, is sense terminals. (The HMC8043 doesn't have sense terminals but it has sense connections on the multi pin connector round the back and I see with the NGE100 series the connector has been removed).

This is a pity as with low voltage high current (3A) the voltage drop may be significant. Having said that, my present supply has sense terminals and I leave them permanently connected to the output terminals so perhaps it is not that vital to have them in practice.

[TheAmmoniacal]

The NGE103 is $1234 here (incl. VAT) ... 

Specifications attached.

[Octane]

I ordere the NGE103 last Thursday from testequipment.com. No expected shipping date yet 

I'm just building up my new lab here, so won't have much to test it with, but maybe I can do the one or other thing for whom is interested.

[jpb]

Looking at the spec sheets and prices on Farnell UK and comparing the NGE103 at £687 + VAT to the HMC8043 at £836 + VAT, the extra 22% of the HMC8043 seems to buy you:

four times better ripple (450uVrms  4mVpp vs 1.5mVrms 20mVpp),  two times better current ripple (1mA vs 2mA) but worse response time (1msec vs 200 usecs). The extra connector on the back of the 8043 is more useful for permanently wiring in a rack and provides voltage sense to compensate for long cables.
Arbitrary points are reduced from 512 (8043) to 128 in the NGE103.

In round numbers, the UK prices with VAT are £1000 for the HMC8043 and £180 less for the NGE103. Neither of them are exactly cheap - personally I'd probably go for a bulky but lower ripple and higher output like a TTi PL series.

[Octane]

I got my NGE103 today and already thought I would have issues. At first channel 2 always showed an output voltage about 300mV above the set point. Slowly decreasing from 300mV to 200mV over about 30s. I didn't measure it longer.
On channel 3 the current set point was way off. I set it to 500mA and measured about 600mA with the ampere meter. When I set the current set point to 20mA it immediately went into CC mode without anything connected to the terminals.
I turned it off and did other stuff. Now that I tried it again, everything seems to work. All voltages are on and the current limits work on all three channels. Although the current measurement sometimes oscillates between 0 and 40mA when set to 20mA, but the multimeter shows 20mA delivered at all time. The display settles eventually after a few seconds. Let's see if that keeps happening.

Other things: the box contains 4 power cords (US, European, UK, Australia), this is nice.
But the US cable is barely a meter long (didn't look at the other ones, but they seem about the same). Come on R&S.
The power supply was set to 230V input and the T2.5A fuses were fit. But two T5A are in the box.

Anyways, let's see if it works the next days, of if I have to send it back.

Michael

[Octane]

I played a little further with the power supply. I didn't have much time the last days.
So it seems that all the voltage offsets are gone and now those are spot on on all three channels.
There are only two issues left:
Whenever the voltage is above roughly 5 volt, and I short the output with the multimeter measuring current, the voltage drops immediately to zero, but also the current is zero for about a second or a little less until it rises to the set value. I measured this once with max min hold and the max value showed about 150mA for a set current of 50mA. So it overshoots quite dramatically. Below 5 volts every channel behaves as i would expect. The current basically flows instantaneously when I short the outputs. This behavior is the same for all set currents. As I said it depends on the set voltage.
The second thing is, that sometimes, although the delivered current is correct (Multimeter measurement) the display on the supply jumps around the real value for a few seconds until it settles to the correct one. For example, for a set current of 50mA it jumps around between 10 and 80 mAor thereabouts.

So I'm not sure if this is a hardware problem, or can be fixed in software. Right now I can do only those basic tests since I have no power resistors or any other stuff for testing at hand. I also didn't have time to hook up the scope to see the transient behavior in detail. If Rich from R&S is reading this, maybe he can forward this to the power supply guys at Rohde for a comment.

Michael

[Joel_l]

Happens I've been looking for a power supply. To me, these are a miss at only 66W, 100W, and 10mV steps at the price point.

Try again

[Octane]

You may be right, I thought this would be R&S quality, but it behaves and feels more like a cheap Chinese Rigol or Siglent. Also the banana posts have kind of the feel of cheap brittle plastic.
I'm really tempted to send it back. Bummer.

[Rich@RohdeScopesUSA]

I played a little further with the power supply. I didn't have much time the last days.
So it seems that all the voltage offsets are gone and now those are spot on on all three channels.
There are only two issues left:
Whenever the voltage is above roughly 5 volt, and I short the output with the multimeter measuring current, the voltage drops immediately to zero, but also the current is zero for about a second or a little less until it rises to the set value. I measured this once with max min hold and the max value showed about 150mA for a set current of 50mA. So it overshoots quite dramatically. Below 5 volts every channel behaves as i would expect. The current basically flows instantaneously when I short the outputs. This behavior is the same for all set currents. As I said it depends on the set voltage.
The second thing is, that sometimes, although the delivered current is correct (Multimeter measurement) the display on the supply jumps around the real value for a few seconds until it settles to the correct one. For example, for a set current of 50mA it jumps around between 10 and 80 mAor thereabouts.

So I'm not sure if this is a hardware problem, or can be fixed in software. Right now I can do only those basic tests since I have no power resistors or any other stuff for testing at hand. I also didn't have time to hook up the scope to see the transient behavior in detail. If Rich from R&S is reading this, maybe he can forward this to the power supply guys at Rohde for a comment.

Michael

Hi Michael - I'm just seeing this.  I'll get your feedback to the NGE design team. 

-Rich

[Octane]

Hi,

I tried the supply again today and after switching the outputs on, channel 2 was set to 5V but startet out with 5.3xV and dropped slowly over half a minute to the set point. I didn't have a multimeter connected, but even if it's only a display problem it is not how a ~US$1000 tool should behave.
Overall I'm really disappointed by how this Rohde & Schwarz NGE103 performs.
Again, I thought even though the specs are low for a supply in this price range I support a private German company that i admired for their quality tools. I hoped the performance would be solid (no overshooting currents or voltages). Not for this NGE103. It is pathetic if that is how it is supposed to behave, especially the behavior with the current limiting that I described in an earlier post.
I guess I will send it back and go for a BK precision one with higher specs for 2/3 of the price.

Rohde & Schwarz: I understand that you usually sell quality gear (I got one of the RTB2004 fully loaded and really like it, and will love it if the next firmware version fixes the bugs), but this power supply is not what it should be. Too pricey, especially if it doesn't work

Michael

[TheAmmoniacal]

Hi,

I tried the supply again today and after switching the outputs on, channel 2 was set to 5V but startet out with 5.3xV and dropped slowly over half a minute to the set point. I didn't have a multimeter connected, but even if it's only a display problem it is not how a ~US$1000 tool should behave.
Overall I'm really disappointed by how this Rohde & Schwarz NGE103 performs.
Again, I thought even though the specs are low for a supply in this price range I support a private German company that i admired for their quality tools. I hoped the performance would be solid (no overshooting currents or voltages). Not for this NGE103. It is pathetic if that is how it is supposed to behave, especially the behavior with the current limiting that I described in an earlier post.
I guess I will send it back and go for a BK precision one with higher specs for 2/3 of the price.

Rohde & Schwarz: I understand that you usually sell quality gear (I got one of the RTB2004 fully loaded and really like it, and will love it if the next firmware version fixes the bugs), but this power supply is not what it should be. Too pricey, especially if it doesn't work

Michael

Would you be willing to characterize the behaviour with the scope? Does it really overshoot on CC? How fast is it?

[Octane]

Would you be willing to characterize the behaviour with the scope? Does it really overshoot on CC? How fast is it?

Sure, I'll try to get a few basic measurements done. I can't do much since I don't have many resistors or other parts. I'm just building my lab.

Michael

[Octane]

Hi,

I did a quick test with the scope: 20V output voltage, current limit set to 50mA. Putting a 330R resistor across the output and capturing the resulting voltage with the scope. That outcome can be seen in the image attached below. Pretty pathetic. The voltage stays at the 20V when the resistor is connected (around 60mA, remember 50mA limit is set) and then drops a little bit after ~150ms staying at one level for about 600ms before it drops to the 50mA it is set to. So from connecting the load to reaching the set current it "only" took about 1s. Pretty bad.

Now a few videos:

https://youtu.be/CVJEZAvv9l4
In this video I short the output with the amp range on the multimeter. Voltage set to 20V, current limit of 50mA. As soon as I connect the meter, the voltage drops to 0 volts and it takes about a second to rise up to the current limit of 50mA. You also see the current display wildly fluctuating until it sets to the 50mA, whereas the meter shows the 50mA as soon as the output rises.

https://youtu.be/VKatT8dCHn0
Here I have a current limit of 50mA with an output voltage of 12V. Again connecting the amp meter across the output. Same delay as before, but now it also supplies almost 80mA and is steady but slowly dropping. So again, total fail.

https://youtu.be/cyDhJy3BPSc
Now I'm using the 330R resistor again. Voltage set point is 12V, current limit is 30mA. When I connect the load 37mA are supplied without ever limiting to 30mA.

https://youtu.be/KFM-quOGaLY
Same settings as in video before. Shorting with amp meter. Now it supplies 60mA on a set point of 30mA.

Ok, so I registered for a youtube account only to be able to post those videos here, so please let me know if they don't work, or any other thing is wrong.
I think with this testing, the fate of the supply is sealed. It will go back and I will be looking for another brand.
About US$1000 is ridiculous for this supply, I only would pay the premium if I would have gotten R&S quality.

Anyways, hope this is informative.

Michael
 
Edit: Grammar...

[colorado.rob]

What's it cost to enable the Ethernet port on one of the NGE103?  I'm looking for a 2-3 channel LAN/LXI benchtop supply under $1000.  This seemed to fit the bill until I noticed it had "optional ethernet".  I'm guessing that'll put it out of the running and close to the price of the HMC8043.

[Octane]

On Testequity it is US$150. So yeah, the HMC might be a better deal. In hindsight I don't really understand why they have the NGE103. The HMC8043 seems to have better specs and more standard features for essentially the same price.

Michael

[Hensingler]

Think I would rather pay 20% more for this much more capable PSU

http://uk.farnell.com/aim-tti-instruments/mx100tp/power-supply-3ch-70v-6a-programmable/dp/2457410

315W, 16v/6A through 70v/3A, remote sense, earth terminal, keypad, all remote options standard, and really nice binding posts with integral 4mm safety sockets.

[colorado.rob]

Think I would rather pay 20% more for this much more capable PSU

http://uk.farnell.com/aim-tti-instruments/mx100tp/power-supply-3ch-70v-6a-programmable/dp/2457410

315W, 16v/6A through 70v/3A, remote sense, earth terminal, keypad, all remote options standard, and really nice binding posts with integral 4mm safety sockets.

Nice recommendation!  I just pulled the trigger on that puppy.  Saelig are having a sale on these units and with the EEVBLOG discount, it was just a hair above my budget.  It seemed well worth the stretch.  I really like the sense ports in the front, even if some find them hard to use.