Hi,

I have a pcb in a coffee machine which drives a solonoid from a 24v dc supply. I decided to run the coffee machine with a 24v dc submersible pump inside a canister. The pump shorted, blowing an ic(uln2003A, i think) on the board. I powered the pump off the same supply to the solonoid, as i would need the pump on when the machine switched the solonoid on. How do I protect the ic from another short in the future?

Many thanks,
Dion

 

Use a current limiter (a lower power transistor and a higher current transistor - see google or details). Also add a fuse to blow after a few fractions of a second in an over-current situation.