Monthly Archives: July 2014

Protect your module power inputs

This is an interesting solution, from, to provide protection against reverse connection of power supply as well as overcurrent protection caused by any kind of short circuit:

Power input protection and filtering is highly recommended for all modules! See below.

Module Power Input Protection

PS1 and PS2 are polyfuse resettable fuses available in various mA ratings. A typical module with a 50 mA current draw would use 100mA versions.
A power supply reversal causes the diodes to conduct, creating a short circuit. That condition or a short on the PCB causes the polyfuses to heat up and go into current limiting.