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I have an RGB LED strip which according to what I found online can eat up to 8 A at the length I am using. I bought a power supply which supplies 5 V / 8 A and the LED strip runs fine off it.

I have wondered though, if I were to connect a power supply that is able to provide only say 5 V / 1 A and drove the LED strip to shine bright white light (making it require more power), could that permanently damage my LED strip?

I'd try this but if the answer is yes I'd not like to find out another way. I am also interested in if it could damage the power supply, but I wouldn't mind that as long as the LED strip remains undamaged.

I found a related question which seems to suggest with some more complex electronics, this can be a problem, but I don't think LED strip has anything in it which may cause a permanent failure in cause it is underpowered? It's an addressable LED strip so there are logic components in it, but there are no power transistors.

Tomáš Hübelbauer
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Using a 1 Amp power supply to power an LED strip that required 8 Amps is likely to damage the power supply, unless the supply includes over-current protection.

In any case, the power supply's output voltage will drop when you try to draw excessive current from it. This will cause the LED strip to not work (or to not work correctly), but should not cause any permanent damage to the LED strip.

Peter Bennett
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Your LED strip would probably be fine, mostly because the power supply will either...

  1. Go into current limit and drop the output voltage so the LEDs will fade out, or
  2. Blow a fuse, similarly protecting your LEDs, or
  3. Brown out, dropping the output voltage, and getting VERY hot, and maybe even letting out some smoke.

Which of those happens will depend on the type of power supply.

I say probably fine, because there are no guarantees. A simple "brown out" should not damage the load, but with a cheap power supply there is the possibility that an over-current failure may allow the full voltage the thing is regulating the 5V from can make it onto the output.

As such, using a power supply not rated for the load is never a good idea unless you know exactly what it is going to do.

Addition:

If you are designing something that you know will only have 1/10 of the LEDs lit at a time, and want to save money on the power supply, then you should include a current limiter in the power circuitry to the LEDs. That way if you mess up and have too many on, only the LEDs will fade out, not whatever is controlling them.

Trevor_G
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