I wanted to make an H bridge which was capable of braking the motors. I came across Bob blick's design and tried it on breadboard, I also tried his PCB. So far only the motors turns in one direction on supplying input IN A as in his diagram, IN B is not working. Did anyone try out this circuit before? Someone please verify it.

http://bobblick.com/techref/projects/hbridge/hbridge.html

 

There seems no reason why both sides would not work, they are identical?
Max.

 

1. Exchange the bjts from left to right and right to left, separate high side and low side, exchange twice.
2. measure the voltage of each pin of bjts for Q1,Q5,Q4,Q8.

 

The circuit works fine and the transistors dont heat up when both inputs are one. Sorry!