K8055 Quad Motor controll/PWM/Transistor/H-Bridge


I’m on a project where I need to control 4 motors using my Velleman K8055, all motors are bi-directional and I’ve already constructed the H-bridges necessary. I control the motors using all of my 8 digital outputs on the k8055. One output is for one motor and one direction. So the digital outputs 1 & 2 is controlling the first motor.

Now, I’ve planned to control two of the motors speed using the 2 PWM outputs and a transistor (and diods) but I wonder, since I’m going to use the motors in pairs, is there any way for me to hook up two of the motors to one transistor/PWM and thus making them spin at roughly the same speed (not very necessary). Remember the motors will be spinning in different directions when I want them to using the H-bridge.

I know I cant replace the motor in the picture below(see link) with the +12v and GND to both of my H-bridges because of the possibility of motors creating back voltage. If you’ve read this far I thank you and hope that you might be the one who can awnser my questions.


Is there a way for me to connect two h-bridges(controlling two motors) to one transistor?

Best regards

Please see the last circuit diagram in this thread:
There are the PWM outputs connected to the H-bridge to control the motor speed.

The PWM outputs are open collector outputs.
You can connect the PWM output to two H-bridges too.