Hi Dave
Well, I wouldn’t exactly say that it was rebuilt, but I have more or less got it working as I intended! The principle issues were rewinding the D1 relay, replacing some capacitors, resistors and diodes, adding BR, and trying to work out how to wire the Startomatic panel into a control box which is designed for button start, which took quite a while.
I will try to check out your queries, but it might take a day or two. However, I’m slightly puzzled by differences in CH for 12V vs 24V because I understood that it provides a back EMF from the generated mains voltage, so should be the same. Certainly, mine was from a 12V system, and is working ok on 24V. Also, the circuit diagram suggests that the only difference between 12 and 24V in the Startomatic panel is the BR resistor. I have also provided for a variable resistor on the D1 relay, but I’m not certain that it was necessary.
All best
Tony