[sdiy] circuit protection question

[Steve Ridley]

> is there any advantage to running a reverse rectifier diode to ground/antiparallel over 
> running it in series with the supply line


Yes - sometimes the reversal can come from the other direction!


Consider a circuit running off +ve, 0 and -ve rails. If the +ve develops a fault (shuts down or goes open circuit) components connected between the +ve and -ve supply will drag the +ve rail down towards the -ve supply, almost certainly taking it negative wrt 0v. I've seen this happen on several occasions, and a diode in series with the supply won't help.


Steve