Entry Level Power Supply 30V@5Amp

I have a Tenma, the 3 A version and it's ok.

What it has over the other two, is memory. I don't use that on any of my supplies, mainly because the memory function is poorly implemented, but if I were to pick the best implementation, it's probably on the Tenma (because it has direct access to the memory slots).

What I'm not happy with is the fact that you have to press voltage/current in order to enter edit mode and it gets out of this mode in a couple of seconds.

Again, it's an ok power supply and I use it a lot.

Razvan

TENMA has mixed reviews on-line. Recently I invested some time by loaning a Konrad Power (KP) supply (which works like TENMA basically) and Rhode und Schwarz (R&S) power supply. Although the R&S one is old and can only 0.8 amps and the KP was with 5 memory channels upto 3A the performace was vastly different.

When it came to drawing larger currents in a fast Vin time the R&S performed much better than the KP. For the KP one could see in the power rise signal that there were certain voltage drops and how much higher the input current was set the KP was not able to deliver it in a short time.

I recorded some data on the scope too I will publish it. All the time I thought that the DC DC converter under test was not performing well with noise in the output but when I measured with R&S the results were much better.

So I am a bit skeptical about it.

Cheers

Nidhi

If you want a general purpose bench supply it's really much better to go for a linear regulator design rather than a switcher. (Switching power supplies are often poor at testing switching loads like DC-DC converters.).

These things last a long time the supply I use most is a Thandar TS3021S 30V 2A bought 17th April 1998 They make a similar supply still they have changed their name to AimTTi and the model number is  EL302REL302R

I have lots of other supplies, including R&S, Rigol, several "own brands", Xantrex and so on - the 3021 gets used because it's quiet, low noise, quick to adjust and never does anything weird or un-expected.

All the others get used for semi-permanent set ups or when their special characteristics are needed.

The  EL302REL302R costs£180 VAT so may well be outside your budget but I would look for a second hand one(or similar in your place

There are a few on Ebay.

MK

If you mean Korad, then yeah, they're the same supplies.

Regarding your test, I wouldn't jump to conclusions based on that, because it's possible the inrush current was simply too high for the supply (and maybe it shouldn't have been delivered anyway), but that's impossible to tell without taking some measurements. You could take a look with a scope at the input current for the DC-DC converter - if it goes above what the PSU is set to deliver, for a relatively long period of time, then it might be normal for it to malfunction and perform poorly.

All power supplies are able to deliver more current then they are set to deliver, in short spikes, and there's a lot of variation in this aspect across power supplies. There are applications for which you want your power supply to be able to deliver longer high currents spikes and other applications (like when dealing with sensitive electronics) when you absolutely don't want that. This means that neither way of doing it is bad, it's just that some supplies are better than others for particular purposes.

Don't expect HP or R&S performance out of it, but it's decent and behaves as you'd expect it to behave. It's definitely a good buy for the money.

Razvan

I would also agree that power supplies with linear regulator do a better job for generic purpose circuit analysis as compared to the switching types.

I did some tests with both types now. Indeed you get what you pay for in the end. As of now I am limited from the budget side.

Lineares Labornetzgerät VOLTCRAFT LPS1305 0 - 30 V/DC 0 - 5 A 150 W is looking as my best option as it is linear type but ofcourse with only one set of inouts. This power supply has the bad review of being loud when in operation but I think I will have to live with it.

I will keep my eyes on the  EL302REL302R As of now I haven't found a used one on the Internet which delivers in Germany

Cheers,

I would also agree that power supplies with linear regulator do a better job for generic purpose circuit analysis as compared to the switching types.

I did some tests with both types now. Indeed you get what you pay for in the end. As of now I am limited from the budget side.

Lineares Labornetzgerät VOLTCRAFT LPS1305 0 - 30 V/DC 0 - 5 A 150 W is looking as my best option as it is linear type but ofcourse with only one set of inouts. This power supply has the bad review of being loud when in operation but I think I will have to live with it.

I will keep my eyes on the  EL302REL302R As of now I haven't found a used one on the Internet which delivers in Germany

Cheers,