Shopping for a bench power supply, Advice?

[EasyGoing1]

Hello,

I've never owned a bench power supply before, so it's time to get one.

My price range is around $100, and what I'm looking for, is the knowledge from past experience. If anyone can comment on what I should be looking for in terms of features and capabilities, or what I should be looking for in terms of “gotcha's” ... Would be much appreciated.

I do remember reading somewhere, that some power supplies will use pulse with modulation, and I honestly don't know if that's really common problem or not or even how I would identify a power supply that does that because I would certainly want a digitally controlled power supply that outputs an analog and clean signal. And a programmable via USB sounds like fun, but is that capability truly worth the effort or is it just more “gimmicky”?

Thank you very much for your time.

[stj]

Re: Shopping for a bench power supply, Advice?

you need to asses your maximium voltage and current needs.

[EasyGoing1]

Re: Shopping for a bench power supply, Advice?

you need to asses your maximium voltage and current needs.

I figure 30V at 5 Amps will be plenty for my needs.

[sam_sam_sam]

Re: Shopping for a bench power supply, Advice?

I will give you a recommendation if you work on LED modules I would get the 60 volt @ 5 amp you might pay a little more for it but to me it worth the extra money

I would also recommend not getting a switching power supply version if going to test motor and the like

I have one that is 30 volts at 10 amp I only use it for testing car stereos / car amp and LED modules ( this power supply I have already had to repair the switching power supply regulator and recapped it )

I would recommend getting a transformer type of bench power ( you can abuse the shit of these and for most part will survive I have about 5 different voltage and or and amperages and so far I have only repaired one of because of stupid shit )

The view points are my own if I were buying one now with the knowledge that have this is what I would buy

I hope this helps

[stj]

Re: Shopping for a bench power supply, Advice?

https://www.youtube.com/user/sdgelectronics/videos
this guy has reviewd a number of good psu's

[Curious.George]

Re: Shopping for a bench power supply, Advice?

I figure 30V at 5 Amps will be plenty for my needs.

Don't just come up with some numbers; sit down and "what-if" different scenarios and see how your needs might change. Then, look over the list of requirements and see if any of the outliers can be eliminated ("Do I really need to have a bench supply to handle THAT particular scenario? Or, could I handle it better with some other approach??") to get you to your "what you REALLY need".

As far as features are concerned, my favorite supplies are triple output, digitally programmable (GPIB -- old tech -- and front panel keypad). They have built-inn metering so I can set a current/voltage limit and observe how the voltage/current changes -- useful when powering up something "unknown" (or, as a cheap battery charger!).

I also like being able to push a button and have the output inhibited -- or enabled. An on/off switch that doesn't require dicking with the present settings.

The tougher requirement to specify is what the power transitions look like. Does it snap on/off? ramp up/down? etc. Some loads are very fussy about controlling the power supplies as they come on/go off -- expecially when you have more than one supply feeding a circuit!

[EasyGoing1]

Re: Shopping for a bench power supply, Advice?

I will give you a recommendation if you work on LED modules I would get the 60 volt @ 5 amp you might pay a little more for it but to me it worth the extra money

Well, I will be working with LEDs but rarely would I be needing more than 19 volts, and typical circuits that I work with are about 9 volts.

I would also recommend not getting a switching power supply version if going to test motor and the like

This reminded me that I forgot to ask in my OP... what is the difference between the switching types and the non-switching types? Do the switching types use PWM or something? Is the output wave noisier?

I have one that is 30 volts at 10 amp I only use it for testing car stereos / car amp and LED modules ( this power supply I have already had to repair the switching power supply regulator and recapped it )

I would recommend getting a transformer type of bench power ( you can abuse the shit of these and for most part will survive I have about 5 different voltage and or and amperages and so far I have only repaired one of because of stupid shit )

The view points are my own if I were buying one now with the knowledge that have this is what I would buy

I hope this helps

Except that I can't quite tell which PS you're recommending unless its a 60V at 5A NON-Switching type?

[sam_sam_sam]

Re: Shopping for a bench power supply, Advice?

Except that I can't quite tell which PS you're recommending unless its a 60V at 5A NON-Switching type?

Yes this is the non switching type of power supply

One note if you decide to buy this one make sure that it linear power supply not a switching power supply

https://www.ebay.com/itm/30V-60V-10A...r=631736358588

Because when I went looking for one I saw a lot of switching power supply versions and very few linear ones you find a few of them in the 30 volt version but not in the 60 version

If you do decide to buy a switching power supply version I highly recommended that after you run it over 24 hours to make sure that you have no issues then recap the boards if the capacitors are not a brand name you recognize I recommend highly torture test the hell out of it short the leads together to make sure it can handle the amperage load ( before you recap the boards )

In a switching power supply type they use a switching power supply regulator ic of some sort some switching power supply regulator are better than other the problem is you do not any idea what type they use until you get the power supply and open and find what ic chip has been used

[sam_sam_sam]

Re: Shopping for a bench power supply, Advice?

Here is the post about the bench switching power supply

https://www.badcaps.net/forum/showthread.php?t=72557

[stj]

Re: Shopping for a bench power supply, Advice?

btw, what's the price limit??
are we looking for a used HP, cheap chinese thing for <$100,
or a new linear job like from Rigol. for closer to $400??

[eccerr0r]

Re: Shopping for a bench power supply, Advice?

Thought question of the day: Some linear adjustable power supplies have a relay switch to reduce power consumption.

Can these be called switching power supplies?

[Harvey]

Re: Shopping for a bench power supply, Advice?

Thought question of the day: Some linear adjustable power supplies have a relay switch to reduce power consumption.

Can these be called switching power supplies?

Mine has a big red switch on the front....https://www.youtube.com/watch?v=p2EMnCi1RFI

[stj]

Re: Shopping for a bench power supply, Advice?

the relay he's talking about changes transformer windings to reduce the voltage drop across the transistors.

[EasyGoing1]

Re: Shopping for a bench power supply, Advice?

I have a question: How can a power supply be both linear AND switching?

For example: https://www.amazon.com/Kungber-Adjus.../dp/B08DJ1S7J5

[sam_sam_sam]

Re: Shopping for a bench power supply, Advice?

From the picture that they have it is a switching power supply

[eccerr0r]

Re: Shopping for a bench power supply, Advice?

probably using the term incorrectly, this is a switching supply. Linear is probably referring to the ability to linearly select voltage and current instead of having to go to discretely choose specific voltages (which is "adjustable" too.)

Or it could refer to a dual stage regulator... of which the postulation also qualifies.

[stj]

Re: Shopping for a bench power supply, Advice?

it could be a fixed switching psu instead of the main transformer, but still feeding into a variable linear regulator for the final output.
that would reduce weight and cost.

[EasyGoing1]

Re: Shopping for a bench power supply, Advice?

From the picture that they have it is a switching power supply

probably using the term incorrectly, this is a switching supply. Linear is probably referring to the ability to linearly select voltage and current instead of having to go to discretely choose specific voltages (which is "adjustable" too.)

Or it could refer to a dual stage regulator... of which the postulation also qualifies.

it could be a fixed switching psu instead of the main transformer, but still feeding into a variable linear regulator for the final output.
that would reduce weight and cost.

OK, so then at least this confirms that a power supply can't truly be both - fundamentally that is ... I was hoping I wasn't missing something.