EDIT: there is an NPN-only based attempt here: https://forum.arduino.cc/index.php?topic=734543.msg4944098#msg4944098
I don’t have an H-Bridge IC at home, ordered some but thought, how hard could it be? It’s just a bunch of transistors and diodes, right? Not for me (Q leading to this one).
I have a circuit that works more or less but I made some “sacrifices” along the way.
On the diagram, I marked the main current with lime line. There is a blue line that indicates that the right switch is on, right PNP and NPN transistors have voltage on their bases. Right PNP is off, right NPN is on.
I have a biig problem though. I introduced 3 diodes D1-3 (not flyback diodes, they come later).
D2, D3: they were needed to make sure that in initial state, when current flows from Emitter->Base of the PNP transistors, and neither switch is on, the NPN transistors remain off. But with that, I have a voltage drop of 0.7V to base of PNP from the switch, therefore, I won’t ever be able to switch off the PNP completely due to big enough potential difference between E-B.
D1: to work around the problem of PNP not switching off completely, I put in another diode, D1. This however means, that the max voltage I can work with is VCC-0.7, I’m not too happy about.
Q: is there a way to get rid off the Diodes in such a way that the behavior of the circuit doesn’t change?