Breadboard powersupply question

what does everyone recommend for a good breadboard/prototyping power supply?
Must include:
Variable volt/amps
Won’t burn down the house
Under $100

Any suggestions would appreciated. Don’t need something super crazy, maybe 15V output tops. I don’t trust Amazon reviews as some say they are not certified in the US.

@artg_dms He’s the perfect guinea pig. Nab him!

I have a regulated power supply (~$90 - overkill) but that is really used for electro plating.

But go cheap and convenient: I’ve used old wall warts (I probably have 20 for old various things I don’t have any more) , 3V, 5V, 12V. On several I’ve just bought the female pigtail plug, then plugged the wires into the breadboard.

Or I cut off the male plug, strip the wires, use DMM to see which is + or - and plug those in.

You can also get small battery holders and plug them in, They come in 1, 2, 3 , 4 and more sizes

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Thanks for the reply, I have a wallwart that outputs 5V and 1.2 A . What do you recommend in terms of amps for safe use? I also have one that outputs 9volts at 600 ma. I’m thinking that’s too much current for what i’m trying to do (power a few IC’s).

Definitely trying to stay away from batteries as they are expensive and although would like them to be used in the final application, i’m going through a lot of batteries at the moment just prototyping.

I’ve also been looking at breadboard power supply modules that fit into the breadboard, which seem the most ideal.

This is just my ignorant uninformed opinion: For bread boarding it is usually matching the voltage as there isn’t much power draw. have some of the battery holders, whatI like is I don;t need to be near an outlet to plug in. Don’t use them all the time, but between wall warts and those, take of very little room in parts box.

Garage sales and Freebie shelf great source for free or cheap wall warts,



That’s good price, Like I said mine is for plating 0-30V 10 amps. Overkill for bread boarding. This looks nice and portable and has the V range and Amps for bread boarding.

This is a common misconception. The more amps the more the supply CAN handle, but it doesn’t push those amps until they are needed. You can use a 100A supply, and you’d be fine, unless you accidentally short it because it would get hot pretty fast lol. I’d say any supply under 10A should be just fine.

If you’re planning on making it battery powered, you could always get some rechargeable batteries, and use those for your prototyping.

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One should always employ the current limit knob and set it to a value perhaps 125% greater than the expected load of your circuit. This will prevent the release of magic smoke.


Lucas Brand being the most famous1

Not at first! Let him learn from his mistakes. Let him learn why he does that lol.

Also, his post, he was mentioning a wall wart, which doesn’t have a limit. He’s not going to start a fire or do much other than toast his components in the sub 5A range.

Couldn’t disagree more, but I support your right to express your view.

Newbies will fry components in the natural course of experimentation, but early massive failures can be a deterrent to continuing the hobby.

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The safest wall wart to use is one that has the initials “L.P.S.” near the UL label. The LPS identifies the wall wart as a Limited Power Source. No matter what you do with the output wires you will not burn the house down; short them, back feed a higher voltage, pull too much current, whatever.

How do I know? I used to work for UL and did plenty of testing of these wall warts and similar rated power supplies.

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ELab has 2 of these BK 1550. They have held up well to the (ab)use of our membership. @Raymond repaired one of them. It has current limiting and will run steppers / servos / leds, etc. For the long run I’d spend more on a name brand w/ proven record.

You could roll your own. Transformer, bridge rectifier, caps, LM117, etc. Good for 1.5 A if well heat sinked.
Lots of cookbook / app note circuits out there. Can be easily done w/ recycled parts.

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If you want to buy one for your own use… I have a triple output listed on Makertrade for $125 that I’d let go for $75. Voltage regulated, current limited (to protect against shorts) with 2 variable outputs and 1 fixed 5v output.

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