I have a dead PSU. I opened it up, and I found three bulging 1000 µF general purpose-type crappy electrolytic capacitors. I've replaced capacitors like this on several motherboards in the past, so this will be fairly trivial to do, but the only capacitors I have handy are low-ESR types. Could a swap like this work out, or should I grab a few general-purpose capacitors from a supplier?
Answer
Generally, low ESR can be used to replace general purpose capacitors, but there are situations where the low ESR capacitor could cause oscillation due to the use of a finicky regulator.
For example, the LM1117 is a very common semi-LDO regulator (mostly because it's cheap and you can get them very easily).
It has requirements as follows (from the datasheet):
The ESR of the output capacitor should range between 0.3Ω - 22Ω
A lot of low-ESR 1000uF parts are better than that (by more than 10:1 in some cases).
You could always add a series resistor to degrade the low ESR parts.
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