24VAC Transformer from Air Handler, 7805

[Archangel]

> Maybe a voltage divider before the regulator . . . ?

Single-handedly Joe you've just created a ready-market for all those WW-II surplus dropper Resistors that nobody knows what to do with... brilliant! Even better, this is for a Heat-Pump application... first job - remove the heat from your own PSU...

This is a furnace, yes? Or buy a transformer . . .