Good Benchtop Power supply

[hey101]

Hey I was looking around for a decent bench top power supply. I bought a cheap 0-15v 2a one from ebay but it just blew up after its second use. I am new to buying them but I do want a decent one this time. My budget is close to $100 but I may go higher if I need to. I probably wont get one that can support 10a but I would love for it to. Even 5a will probably be sufficient. As to max voltage i would at least need 12v but I do not mind if it can support higher voltage. Analog meters are fine but digital is preferred if possible. What would you guys recommend for a decent bench top psu that would support some of these features?

 

[Ramussons]

If you need 12 Volts up to, say, 20 A, use a ATX power unit recovered from a PC.

 

[hey101]

I was actually just reading about that. It sounds like a good idea. I noticed it would give the standard 3.3v, 5v. and even 12v. Although I read somewhere that you could add some other stuff to it to allow it to be a variable voltage one incase you needed it but I have yet to find out the parts needed or the circuit required to do so. Any suggestions?

 

[crutschow]

Perhaps one of these articles will help.

 

[tunedwolf]

You may, if you're very lucky, find a really good quality second hand supply for $100 on ebay, at a market or garage sale etc, but it's a tall order if you want quality. There are loads of new cheap supplies on ebay etc for less than $100, but they are just that, cheap junk, and you would be well advised to stay clear of them. You could possibly build a supply yourself if you use good quality surplus or used parts and there are literally thousands of free designs available on the net to choose from, but I suspect that you will either run out of money, or enthusiasm before you complete the project. My advice is to keep saving your money and buy a good quality, well built and specified supply from a recognised manufacturer like Hameg, Agilent etc, either from a good equipment seller on ebay, or a local lab equipment specialist, it will last you a lifetime if you look after it, and more importantly, be reliable

 

[KeepItSimpleStupid]

I tend to agree, I have a bunch of supplies, but my 12 V one is a Fixed voltage power supply, SELECTABLE from 0-32 V, 10A. It's from Harrison Labs, which was bought by HP. I paid $15 some 35 years ago. Replaced 3 transistors because it was repaired improperly and only got the manual about a year ago. You have to change the transformer taps depending on voltage. I also have a +-(12-15 V) and +5 that was part of something. It does not like reverse voltage. It takes out the 723 regulator. Then i have a couple of 0-30 3A supplies. For fun, I "boxed" a ebay step-down regulator with both 5.5/2.1 and 5.5/2.5 inputs and has an adapt-a-plug output. It has LED meters and current limited. So, I can replace nearly any wall wart I have to with a working 12 V, 1A wall wart and this regulator.

 

[Ramussons]

I was actually just reading about that. It sounds like a good idea. I noticed it would give the standard 3.3v, 5v. and even 12v. Although I read somewhere that you could add some other stuff to it to allow it to be a variable voltage one incase you needed it but I have yet to find out the parts needed or the circuit required to do so. Any suggestions?

No, the modifications needed to make it "variable" is only of academic interest. The ATX PSU is designed to give a fixed voltage - plenty of current at 5 volts and a decent amount in 12. One can only trim the 5 volts, the 12 volts follows suit.