This is for all newbies who need a speed control for a dc motor as well as forw and reverse operation. The diagramme shows a full bridge to drive the motor in both directions as well as pulswidth modulation. A 10 k poti is used to control the speed. A cable driver is incorporated. The receiver is a quadro optocoupler.
I have not had the time to build and test it. Please let me know if there are problems.