This has been troubling me for a while. A few days ago I mounted this circuit onto my breadboard, and even though it works, it does so very poorly.
The motor I'm trying to drive is a 12vDC motor and it's moving literally nothing even so it moves very slowly and the voltmeter readings show that only 1.9v make it pass the C-E circuit in the H Bridge. I really have no idea why is this happening.
I'm using an old laptop power supply that has a 12vDC output, a 5vDC one and ground. This circuit is supposed to simulate the behaviour of an electric gate. So I went out and watched what the one in my house did. I thought "lets make it go clockwise for a moment, wait for one, and go backwards for one." But my motor is only getting 1.9v out of the 12v it should be getting from the PSU.
¿Can someone point out why is this happening? or make me see a mistake i made please do so; it will be much appreciated. It's frustrating not knowing how to fix it.