Is there any reason that a cell phone charger couldn't be used as a power supply, as long as the expected load was no more than, say, 80%, of the charger rated capacity? I was looking at power supplies (the plug-in wall adapters) for a small project and noticed the phone chargers had an output of 5v at 2 amps, 10 watts. A comparable power supply was 3 times the size and 10 times heavier. The chargers simply output a specified voltage at a maximum rated current, like a power supply, correct? That would be nice if they could, as I've got several old phone chargers laying around.

 

Yep. They work fine. I do it all the time.

Be sure to check polarity, and don't trust color codes.

I use switch-mode wall-wart power supplies all the time. Despite comments that are sure to follow, virtually all switch mode power supplies are regulated at the stated voltage and have the advantage that if overloaded, they reduce the output voltage to protect themselves.

This is not the usual case with line-frequency transformer-based linear supplies. These are often not regulated and often lack appropriate filter caps. This type of supply can be recognized by its basic cube shape (almost equal dimensions in each direction) and heavy weight (because of the transformer).

 

Yep. They work fine. I do it all the time.

Be sure to check polarity, and don't trust color codes.

I use switch-mode wall-wart power supplies all the time. Despite comments that are sure to follow, virtually all switch mode power supplies are regulated at the stated voltage and have the advantage that if overloaded, they reduce the output voltage to protect themselves.

This is not the usual case with line-frequency transformer-based linear supplies. These are often not regulated and often lack appropriate filter caps. This type of supply can be recognized by its basic cube shape (almost equal dimensions in each direction) and heavy weight (because of the transformer).

Thank you for answering, Jon. Finally, saving old stuff that still worked but was no longer needed is gonna pay off!

 

Usually the only problem might be Switching-Noise.
So if your Circuit is particularly sensitive,
You may need to add some additional Output-Filtering.
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