switching between two batteries

[neazoi]

Is there any way to do this **broken link removed** using discrete components?
for 1.2-1.5v batteries

 

[chuckey]

It would be inefficient but I think it could be done. The first objective would be to build a voltage doubler so you have a more suitable voltage to do your controlling with. In the final stage the output from the control would then switch one of a pair of transistors to pass one of the batteries voltage through to the output.
Frank