Aidan wrote:
Dave wrote:

There MUST be a rectifier; almost certainly the secondary of the traffo
will be connected straight to it (maybe via a fuse) so trace the pcb
tracks.

Thanks all. There is a small fuse tucked out of sight above the
transformer. I'll dismantle one and see if I can follow the circuit &
measure some voltages.

24v ac solenoids will generally run happily on 12v dc.

NT