The motor appears to run flawlessly, however after a minute or so it will become extremely warm. I do not have whatever to degree the actual temp however it's far painful to put my palms on it for extra than half of a 2nd. As you can see from your drawing (although it tends not to be intuitive before everything look) - each centre tapped winding is like two magnetically coupled inductors or halves of a transformer winding. While you connect the centre tap to v and floor one end the opposite cease rises to two x v - or attempts to. But every pushed output is hooked up thru a diode to com (anode to driving force, cathode to com). While you ground one stop of the winding and the other cease is connected to v via a diode you are trying to pressure the supply with 2 x deliver (much less a diode drop). Some thing has to provide. As you've got determined.
It was salvaged from an antique electric powered typewriter, and the uln2003a and zener from the driving force board within the equal tool. It is a five wires motor, but the one inside the schematic is 6 wires. I think the best distinction is that the 5 twine model has the 2 middle faucets joined collectively so that is what you see in my schematic. Given the circuit above, eliminate the zener and positioned a resitor and a 100uf 25v capacitor in series between com and gnd (com -> r -> c -> gnd): the motor runs well but nevertheless overheats.