Hi all!
I am busy building a small wheeled robot. My problem is with the switching of the H-bridge. I would like to run the motor from a 8V power source, and the pic from a regulated 5V source. It is in other words, 2 seperate circuits. I am now busy with the prototype on my breadboard, when I ran into a problem. I am using 2X TIP102, and 2XTIP107 transistors, with 1K pulldown resistors, and 1K resistors on the Base. The motor pulls about 1A full load, and 100mA free running.
When I connect the bases to the 8V supply, the motor starts, and runs perfect, but when I connect the bases to the 5V supply, the motor also runs, but the transistors heat up instantly (smoking hot). I suspect that I am doing something fundamentally wrong here....
I THINK a optocoupler (never used one) might solve my problem, but these babies are a bit expensive. I could use two per bridge (two bridges), but ultemately four per bridge to allow for the motor braking function to work.
Any help and suggestions would be appreciated! I am now stuck on this problem!
I am busy building a small wheeled robot. My problem is with the switching of the H-bridge. I would like to run the motor from a 8V power source, and the pic from a regulated 5V source. It is in other words, 2 seperate circuits. I am now busy with the prototype on my breadboard, when I ran into a problem. I am using 2X TIP102, and 2XTIP107 transistors, with 1K pulldown resistors, and 1K resistors on the Base. The motor pulls about 1A full load, and 100mA free running.
When I connect the bases to the 8V supply, the motor starts, and runs perfect, but when I connect the bases to the 5V supply, the motor also runs, but the transistors heat up instantly (smoking hot). I suspect that I am doing something fundamentally wrong here....
I THINK a optocoupler (never used one) might solve my problem, but these babies are a bit expensive. I could use two per bridge (two bridges), but ultemately four per bridge to allow for the motor braking function to work.
Any help and suggestions would be appreciated! I am now stuck on this problem!