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Topic: How to test power supply under a load? (Read 1 time) previous topic - next topic

bratan

I have a bunch of adjustable DC power supplies which I need to adjust to 5 VDC output, but I suspect that when I just test it with multimeter it won't show correct voltage. Would would be a simple way to test it under load? Put some kind of resistor between power supply output and multimeter?
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fungus


I have a bunch of adjustable DC power supplies which I need to adjust to 5 VDC output, but I suspect that when I just test it with multimeter it won't show correct voltage. Would would be a simple way to test it under load? Put some kind of resistor between power supply output and multimeter?


If it's regulated supply (aka. switching) then it shouldn't make any difference.

PS: You could always try one and see ... that's how we learn! :)

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retrolefty


I have a bunch of adjustable DC power supplies which I need to adjust to 5 VDC output, but I suspect that when I just test it with multimeter it won't show correct voltage. Would would be a simple way to test it under load? Put some kind of resistor between power supply output and multimeter?


Measuring the power supply under a 'dummy load' is a good idea. It doesn't have to draw the maximum current rating of the supply to still be a valid test. What type of load is best/easiest to use depends on the maximum current rating of the supply. Be sure if you do use a fixed resistor that it's wattage rating is well above the wattage it will consume.

Lefty

Bajdi

I have a bunch of 10W 5 and 10 ohm cement resistors for this purpose.

JimboZA

Quote
Put some kind of resistor between power supply output and multimeter?


That sounds like you're thinking in series?- I think parallel is the correct way, ie the load is across the power supply and you in turn measure the voltage across the connections. I'm no expert, but that makes more sense to me....
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