5v linear voltage regulator design problem.

[davenn]

show us your circuit so that we don't have to guess

 

[Damien]

show us your circuit so that we don't have to guess

I'll scan a copy of a written circuit if this doesn't make sense as it's a very basic circuit.

12v in - Pin 1
Common earth - Pin 2
5v out - pin 3

A small cap between ground and 5v output pin to smooth out waveform.