Is it OK to use a zener diode in series? Normally I see them across the output of a power source to limit the voltage to the value of the zener.
Putting it in series instead should reduce the voltage by the value of the zener, yes? (so a 5V zener on a 12V supply would give a 7V output).
The thing is, I have a -12V supply and I need a -5V (or near, -7 will do - I have added a couple of Si diodes to drop the voltage a little more) supply from it - BUT - I don't want to lose the -12V supply (that is needed for other parts of the circuit), and I don't have any negative regulators, only positive.
I have tried it and it appears ok, but will it cause problems if I leave it like that?