Terry:

It is not all clear to me how the 12/6 volt switching in James Corbin's existing circuit is setup. As you know he stated quite certainly that he has "just two connections, +12V and the collector of the switching transistor". I worked with the information deemed reliable so far. If James comes back and comments on how the 6V/3V changeover works then I could help figure out how to add that to the circuit.

Michael Karas

PS.....Maybe James will be so kind to post a small schematic portion of the existing circuit. Indeed is he had done that at the outset of this thread it would probably have way less than half the replies that it has right now!!!
MJK