Power supply for home lab - do I really need a R&S?

[FranciscogGomez]

Hello everyone,
A couple of weeks ago I sold my cheapy single-output power supply for good beacuse it is time for me to buy a more decent power supply for my home lab. it will be used mainly for my personal project but also on project from work (HO). These are the requirements:
Hard requirements

• two or three independent outputs
• Protections: OCP & OVP
• Voltage accuracy: <=10mV
• USB or ETH port for basic controlling

Mild requirements

• Sequencing/programmable feature (it's a nice plus)
• Lightweight. (Linear power supply is not a hard req.)
• Price: ~500EUR & ~800EUR 

I have narrowed down my list to the following table:


The best option that I have is the GPP-4323(dark green) but my "professional-side" inner voice it is telling me that the NGE-100 series is a good option for me as well. (realistically, a used one)

I want to debunk the need of a power supply from Rohde & Schwarz and for this, I need your help.
so my question is:

• has anyone bought a power supply from the NGE-100 series  and regretted it?
• if so, could you tell my why?

Cheers
Francisco

[jonpaul]

Dear Sr. Gomez:

Very fine and detailed post.

We can assit you better if you can precice your applications and experience:

eg: you are Beginner, amateur radio, techincial, emgineer, ?

uses: Testing and developing microcontrollers?
General analog circuits?
Batterty charging?

As a hobbyest since 1950s and Electrical enginer since 1968, we always used HP, Lambda, Tek dual or triple linear supplies with analog meters.

We have paid $US 10..50..75..and $250 max.

We found thewm on epay, Ham radio fleas, local asds like craig list etc.

We have no idea for the Chinese or Rhode and Schwartz you seem to be prefering.

We are wary of fancy digital controlled PSU as they are no as reliable or robust compared to simple linear.

Bon chance


Jon

[Hacked]

Hello,

Here is PSU from UNI-T: https://eleshop.eu/uni-t-udp3305s-power-supply-5976.html
I ordered that one two days ago, it should get delivered this week
People sad good things about that PSU, and it checks most your requirements, and price is great.

[Ice-Tea]

Minor remark: if you're actually looking for a 10mV accuracy on your DUT, you kinda need remote sensing. Otherwise, that 10mV is just a number on a screen ;-)

[nctnico]

I'm missing the Keysight E36313A from the list. A rather unique feature is that it has two current ranges so it can measure low currents more accurately compared to other PSUs.

[J-R]

Overall the E36313A is pretty great, with its available rear outputs + sense but you'd have to find a used one to have any hope of reaching the target price point.

Biggest flaw in my opinion with the E36300 series is the front panel control knob UI.  You can't select a specific digit to adjust up and down, so you're left with a somewhat crude acceleration feature.  If you want to do 100mV steps, you would need to program it to do that.  I use the keypad exclusively so no issue personally and I have other bench supplies with better knob UIs.

The GPP-4323 isn't perfect either, there are reports of recent firmware issues as well as some other items.  Also, the load feature has some limitations, such as 1.5V minimum operating voltage.

Could also add Rigol to your list.

[blackdog]

Hi,

My preference is completely analog as far as power supplies are concerned.
And I mean the control part, the older HP/Harrison models are excellent, even for contemporary applications.
On my two workbenches are modern GW-Instek analog models and older HP power supplies.

What I have seen from testing regarding R&S power supply's, that does not make me happy.
Poorly regulating current limitation and digital pre-regulation despite the advantages regarding energy consumption I am also not in favor of due to the commonmode injection of interfering signals.

If you have a power supply with mV resolution this can be very useful, but keep in mind the accuracy specification.
If you really want to know mV accurately, a DMM is still often needed, especially with the larger currents, and as already indicated, remote sensing is then also needed.

A lot depends on what is important to you, for me that is a low level of interference when I am developing something, that does not include an EMC lighthouse, as far as LAB power supplies are concerned. 

I've had a Dutch DELTA 30V switcher, 5-Ampere LAB power supply.
So far, that's the only one I've had on the workbench that I could live with a little bit regarding interference level and EMC.
But because of the very strong filtering, the current limiting was a bit too slow for sensitive circuits.

I have two pieces of GW-Instek GPP-4323 power supply and am happy with them.
If you have the budget, go for the LAN version, that makes it easier to manage the power supply through Testcontroller if you find this easy.
Furthermore, there are people on this forum who make adjustments to the firmware of these power supplies, look it up.

Greetings,
Bram

[rsjsouza]

I'm missing the Keysight E36313A from the list. A rather unique feature is that it has two current ranges so it can measure low currents more accurately compared to other PSUs.

+1 vote for the Keysight model. The low resolution is a very good time and space saver (as I don't need several DMMs around)

Biggest flaw in my opinion with the E36300 series is the front panel control knob UI.  You can't select a specific digit to adjust up and down, so you're left with a somewhat crude acceleration feature.  If you want to do 100mV steps, you would need to program it to do that.  I use the keypad exclusively so no issue personally and I have other bench supplies with better knob UIs.

Another annoyance is its standby without a native "mechanical power switch", which leaves the backlight on and, at times, I hear the transformer buzzing if I have certain types of loads on the same 120V circuit (not entirely the fault of the PS but a power switch would minimize that). 

[HalFoster]

My suggestion would be a (linear) Siglent SPD3303X for a new supply - I have a couple and am very pleased with their performance.  Although if you don't mind analog meters a vintage HP, Kikusui or such are very, very good performers and are pretty much bulletproof.

Hal

[mawyatt]

Agree the SPD3303 are pretty good for the $ (which can be "enabled" for 1mv, 1ma resolution), we have 3 as well as GPP4323. Both types are good and don't exhibit any "surprises" at Turn ON/OFF.

The UI for the 3303 is a little quirky, but one gets used to it quickly, and the terminal spacing isn't standard, but for the $ a good value IMO. GPP4323 is more expensive but has 4 channels and also quite good.

Best,   

[temperance]

No TTi power supplies in the list? I have three TTi power supplies and they are all pretty good.

I really like the PL303 QMD.

2 x 30 V, 3 A.
-Can work in tandem, parallel, independent. (both channels are isolated)
-OVP
-Fine adjust for the voltage.
-Two current ranges. 500 mA and 3 A.
-Lockable
-Lockable voltage range (you can set min. max voltage over which the output can be adjusted)

Inexpensive for what you get. Non switching so no common mode noise all over the place.

[nctnico]

No TTi power supplies in the list? I have three TTi power supplies and they are all pretty good.

I really like the PL303 QMD.

I'm not impressed. I'm not a fan of PSUs with coarse / fine control. A 10-turn pot doesn't cost that much.

[Rydda]

I have the R&S NGE103, and I am very fond of that one. Especially since the fan turns off at low currents. But be aware that the max power output per channel is 33.6 Watt ,so you cannot do 32V @ 3A .

[temperance]

I'm not impressed. I'm not a fan of PSUs with coarse / fine control. A 10-turn pot doesn't cost that much.

Not to mention that power supplies with ten turn pots are rather rare.

[tautech]

I'm not impressed. I'm not a fan of PSUs with coarse / fine control. A 10-turn pot doesn't cost that much.

Not to mention that power supplies with ten turn pots are rather rare.

And painful to use when large adjustments are required.

[nctnico]

I'm not impressed. I'm not a fan of PSUs with coarse / fine control. A 10-turn pot doesn't cost that much.

Not to mention that power supplies with ten turn pots are rather rare.

Not at all. All the older quality power supplies from respectable brands like HP/ Agilent, Delta, etc have ten turn pots. Nowadays you even find these on el-cheapo Chinese power supplies (if they have analog controls).

[thm_w]

E36313A is $2,200 which is a large step up in price, at that point you should compare it to the NGC100/NGL200/etc. I don't think its relevant to this discussion.

I wouldn't buy NGE100 unless it were <$500 used, you can read some older threads:
https://www.eevblog.com/forum/testgear/newly-released-entry-level-rs-nge100-power-supply-series/
https://www.eevblog.com/forum/testgear/rs-nge100-voltage-jumping-around/

There is also the UDP3305S: https://www.eevblog.com/forum/testgear/uni-t-udb3000s-series-udp3305s-udp3000s-e/msg5455556/#msg5455556

Rigol you'd be looking at DP2031 or DP932U: https://www.rigolna.com/products/dc-power-loads/dp2000/dp2031/
Which I don't recommend at this time due to the poor font used.

[FranciscogGomez]

Hello and sorry for my late respsonse,
I will address/ comment back to most of the comments in this one:

We can assit you better if you can precice your applications and experience:

eg: you are Beginner, amateur radio, techincial, emgineer, ?

uses: Testing and developing microcontrollers?
General analog circuits?
Batterty charging?

Hello Jon,

I'm an electrical engineer and my projects are 90% digital embedded systems-related, the 10% extra will be RF & analog circuits (few occasions now and then)

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Thanks for your recommendation Hacked; and for the remark Ice-Tea, it's a good one to keep in mind.

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I'm missing the Keysight E36313A from the list. A rather unique feature is that it has two current ranges so it can measure low currents more accurately compared to other PSUs.

The reason is not the list is beacuse the price, way out of budget.

E36313A is $2,200 which is a large step up in price, at that point you should compare it to the NGC100/NGL200/etc. I don't think its relevant to this discussion.

thm_w, Spot on!
Thanks, I'll trying to get one around that price range +/-150EUR. For the Rigol PSU, I personally don't like their front panel presentation. (for this reason, I did not add them to the list)

What I have seen from testing regarding R&S power supply's, that does not make me happy.
Poorly regulating current limitation and digital pre-regulation despite the advantages regarding energy consumption I am also not in favor of due to the commonmode injection of interfering signals.

I have two pieces of GW-Instek GPP-4323 power supply and am happy with them.
If you have the budget, go for the LAN version, that makes it easier to manage the power supply through Testcontroller if you find this easy.
Furthermore, there are people on this forum who make adjustments to the firmware of these power supplies, look it up.

Thanks for your comment and hint, Bram

No TTi power supplies in the list? I have three TTi power supplies and they are all pretty good.

thanks, temperance. I have added the PL303QMD-P. With -P in order to have the ports for remote control. However, the price is close to the R&S. I'll keep an eye on this one on the second hand market as well.

[FranciscogGomez]

I have the R&S NGE103, and I am very fond of that one. Especially since the fan turns off at low currents. But be aware that the max power output per channel is 33.6 Watt ,so you cannot do 32V @ 3A .

hey Rydda, You are right! I overlooked this important specification from it

[FranciscogGomez]

Based on your previous comments and suggetions, I have update my list:

[Lochstreifen]

Some years old, but nice overview of multi channel PSUs

https://goughlui.com/2019/07/28/rs-hmc8043-psu-review-in-depth-ch1-market-survey/

[FranciscogGomez]

I want to debunk the need of a power supply from Rohde & Schwarz and for this

Serious question:  could I ask why you want to debunk the need for an R&S power supply?  We make very nice power supplies, including the NGE

hey pdenisowski,
For sure R&S make nice power supplies and I do like the build quality of them(hats off). That's why I'm considering to get one. However, the reason I want to debunk the need of a power supply from R&S is from the point of view of single person/engineer with a lab. at home and limited budget compare to a company.
For the price of a NGE103b, I can get a mid-quality but decent power supply (that will do its job) for less money; which will leave my wallet with  extra cash to get more equipment.
What I'm looking for  is to learn from experiences from colleagues that had experienced this dilemma before

Regards
 

[FranciscogGomez]

Some years old, but nice overview of multi channel PSUs

https://goughlui.com/2019/07/28/rs-hmc8043-psu-review-in-depth-ch1-market-survey/

Thanks Lochstreifen,
I really do liked this post.  well... Part1, I still need to read up to Part6.

[tautech]

Based on your previous comments and suggestions, I have update my list:

If you're not in a hurry one of the SPD4000X PSU's coming in a month or 2 might be of interest.
https://www.siglent.com/products-overview/spd4000x/

You've not listed any hard V/A requirements ?

[mhsprang]

You can read some older threads

Old indeed   Most of the information in those threads is from 2017 or 2020 and refers to the older version, which has been discontinued.  The current HW is the NGE100B

Old:  https://www.rohde-schwarz.com/us/products/test-and-measurement/dc-power-supplies/rs-nge100-power-supply-series_63493-387267.html
New: https://www.rohde-schwarz.com/us/products/test-and-measurement/dc-power-supplies/rs-nge100b-power-supply-series_63493-576967.html

But the NGE100B series also has its flaws. One of them is the CC mode.

In constant current mode, the control loop is way too slow. For instance: if you set the voltage to 20V and the current to 10 mA to test a LED and enable the output with a led connected, the voltage will overshoot to 20V for almost 20 milliseconds, before settling on the Vforward of the LED. This will kill the led as the current will be far beyond the maximum limits of the LED.

A test with a 50 Ohm load and a current set to 50 mA let the voltage spike to 18V for 20 ms (I = 360 mA!), after that is decays exponentially over a period of 60 ms to 2.5V (50 mA * 50 Ohm). This is such a serious design flaw that I feel this design should have never made it to market.

This problem has never been fixed in all the firmware updates that have been released over the last couple of years.