Sunday, 4 January 2009
Reverse is sorted out with a little diode logic :). Speed sensor still not working.
I sorted out reverse with a little diode logic to make my forward / reverse switch work how I want it. The switch is a rotary switch with 3 positions. Forward / Neutral / Reverse.
Start is initiated by turning the key. This provides an interlock so the motor wont start if the switch is knocked accidentally.
I still have some problems with the speed sensor. It is dropping pulses at high RPM. It is a 3kHz unit but something is wrong with it. The max Hz of the sensor should be 4000RPM x 40 teeth on pickup = 2666Hz
See following oscilloscope photos.
Output at 30Hz. Nice and square with a bit of wobble.
Sensor output at 100Hz. Lots of dropped pulses.