Hi

I'm making up a small replacement device for a PLC and want to make some
transistorised outputs as bullet-proof as possible (switching 24V at a
couple of 100mA).

Planning to use a bulk standard optocoupler (eg. 4N35) to drive a small
output transistor, but I want this to be short-circuit and over-voltage
proof as possible.  Any pearls of wisdom or standard config. that you use?
(speed is not an issue here).

Thanks

Hamish