After my video-driver is working, I continue with the automatic speed control circuit. I would like to use the circuit from the NBTV handbook, p. 14 (if nobody has a better idea).
My motor is a 6 V so I have to recalculate the 4k7 resistor. How? What are the values I have to put into my calculation?
Another problem: The circuit needs 12 Volt. Can I take it simply from the video-driver 12 V output? For the motor I have a variable transformator (3 V - 12 V), currently set to 6 V. Or could I better use an extra 12 transformator for both and put an extra resistor for the motor?
And my last question: Wouldn't it a good idea to sell PCBs for that circuit in the club shop?