My circuit requires 5 volts and roughly 4 amps. I am using a 5V/10A power supply. I would like to protect against overcurrent and overvoltage (>5V).
Protecting against overcurrent seems straightforward using a polyfuse. My circuit should never require > 5A, so I am sizing my polyfuse accordingly.
But, protecting against overvoltage seems almost impossible while using a 5 volt supply. Nearly all the overvoltage protection methods use Zener diodes, which typically have a 0.6V voltage drop, which would provide less than the 5 volts I need downstream.
Increasing the voltage of my power supply (>5V) to ensure a safer lower voltage (5V) seems wrong to me. It's like increasing the danger in order to decrease the danger. Am I missing something?
I am pairing a 5V power supply with my 5 volt circuit. I'm just worried than someone else could accidently plug in a 12V (or worse) supply and cause damage.