Junghans Anti-climatic ATO clock

[dennishoy]

Gary, please post a picture or two and we can take it from there. Transistors are only used where there are a pair of coils - one being a 'sensing' and the other a 'repulse' coil. The resistance of a PO relay is quite low isn't it? It should be possible to work out how long it would take for the battery to flatten if permanently connected to the relay, then perhaps calculate the proportion for which the contacts are closed and calculate the new life of the battery.

I'm happy to try and help. It should be fairly simple to convert this to a transistor design if you wish.