The circuit I am using is attached. I know the circuit works because it will move the motor forward and reverse on 9V.
When I apply 9V DC to it, things work as they should. I can use my transmitter to forward and reverse the motor.
When I apply 12V DC from a lawn and garden tractor battery, the TIP 127s begin to smoke. I have already burned one out.
After replacing the burned TIP 127 again it works on 9V but again apply 12V DC and more smoke.