Well I've finally got some video of my exploits to show.
This first example shows how the speed varies. I don't have a long enough table to show the full range of speed but this is a good enough "proof of concept" thing.
Download the 900K AVI (DivX)
here
The second video shows a close up of the rear wheels on the car and how the speed of them vary as I change the "pulse width" on the controller. You can see a green light that varies with intensity as more power goes to the motor. I've been using that as an indicator.
Download the 1.2M AVI (DivX)
here
Now I need to confirm the stop/start voltages at the comparator stage and go off and buy some proper resistor values so I can update the schematic with the correct values. Once this is done I willl focus on getting reverse happening as well on the same POT ( as stated before I'll need a daul-gang POT for this).
Let me know what you think....
ph2t.