Pete Verdon wrote:

Sod's law being what it is, the system hasn't cut out since I started
this thread. I'm inclined just to leave it and see if it happens enough
to be annoying. Or is cutting out like this likely to damage the supply?


Also, check the 7812 has a couple of nearby 0.1 microfarad caps on both
input and output legs of the device. They are known for oscillating
without, and drawing excessive current in this fault mode.

--
Adrian C