Wiring multiple regulated power supplies in parallel

Hi . Can I place multiple DC power supplies in parallel , so I get increased current with minimum voltage ? Can I place them in parallel even if their voltages dont match , like , a 24v 1A with a 5v 2A and get xv 3A ? Because I need like 24v and 2A but PSUs are 24v 5A OR 24v 1A (what I have) Any suggestions ? Thanks in advance .

Arman5592: Hi . Can I place multiple DC power supplies in parallel , so I get increased current with minimum voltage ? Can I place them in parallel even if their voltages dont match , like , a 24v 1A with a 5v 2A and get xv 3A ?

Not unless the objective is to make a ton of smoke and/or loud bangs and flashes. You will need a 24 volt power supply with the rating you require. I'm not sure if the 24V 5A PSU was a typo... if it wasn't, use that.

Do not do this!

If you have to connect power supplies in parallel they must be:- 1) The same voltage 2) Connected together by the ground or -ve terminals and connected together on there +ve terminals ONLY through a diode on each supply.

Even then, with regulated supplies it's likely to be a problem. One supply will be a slightly higher voltage, so current will be drawn from that. The other supply sees the higher voltage and it does nothing - the output is above its target level so it doesn't supply current.

Then you exceed the current rating of the first supply and it goes out of regulation. The voltage may sag or it may switch off. Then the second supply which was idling now has to carry the full load itself. It won't do that and it will sag or switch off.

There's a reason why a 10A power supply costs more than two 5A ones and it's not because the manufacturers are trying to rip you off.

MorganS: There's a reason why a 10A power supply costs more than two 5A ones and it's not because the manufacturers are trying to rip you off.

... not any more than usual, anyway ;)

Ok thanks :D I'll invest money on a third PSU or perhaps a motor with less current rating . At first I bought 12v 1A then I remembered I had 14v 1A so it was pointless , Then I bought 24v 1A which might not be enough either . I'd go for 24v 4A or 2A or something . Thanks for the help

If you're doing a lot of tinkering, you might want to just get it over with and buy an adjustable one?

no , not really . I have an old adjustable that's fine for tinkering (500 ma) but not enough for this project . Apparently , I don't need 2A . I dont even need 24v , because today I tested it and it made every motor overheat and working bad (the problem didn't occur with a 12v 1A)

Adjustable DC-DC converters are common and cheap now - I think these could make your life a bit easier. Have a look at ebay:

http://www.ebay.com/sch/i.html?_nkw=dc-dc+converter&_sacat=92074

Nicer ones (smaller, likely more reliable) can be had from various hobby vendors, notably polulu

I know people who’ve made crude power supplies (to deal with their lack of an adjustable bench supply) just by replacing the trim pots on them with larger (ie, easier to turn by hand), and connecting volt meter to it.