Switches S1-S4 are closed to turn the motor in one direction, S2-S3 are closed for another. But at the time of changing motor direction, when switches (transistors) are opened, Back EMF kicks in and makes the switches blow up. That's the reason of using diodes parallel to switches (See figure below).
On the other hand, these diodes consume significant amount of power. I am currently trying to solve this problem, and make a "diodeless" H-bridge circuit work.
I am using an mCU to control the motor with PWM signals. Is it possible to make a flawless timing for switches to not blow up?
For example, on the schematic above, assume that the situation is as this: S1 and S4 are closed and motor turns in that direction. When I want to change the direction, I open S1-S4; and close S2-S3. By this, I have burnt the switches several times. Now, my idea here is to open S1, and close S3 for a while. By this, I think I'll be able to let the remaining current be absorbed (on the circuit S3-Motor-S4). Then, I open S4 and close S2, which reverses the direction of the motor. As I said above, I am not sure about that if it is possible with an mCU. Also, I would need to analyze the characteristics of the motor and switches in order to find the perfect timing for the algortihm.
What do you think about this idea? Is there any method that you know or can suggest to overcome this power consumption issue? I have searched online but couldn't find anything.