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Old 11-28-2009, 07:12 AM   #2645 (permalink)
squiggles
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Join Date: May 2009
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Quote:
Originally Posted by jackbauer View Post
Got my motor rpm sensor up and running today and began thinking of an rpm limiter circuit for the controller. What would you guys think about using an lm2917 frequency to voltage converter connected to the hardware overcurrent circuit in the revolt? It could be setup to drop out the pwm at a certain rpm with low component count. Quite important for myself with an 11" forklift motor.
Is there no counter input available on the micro?
If you speed sensor is giving pulses the easiest method would be for the micro to measure pulse time and compare to a minimum value.

many micros have a counter/timer input that will measure pulse width.

if (pulse_width < min_allowed)
pwm = pwm * 0.5;

Actually I see you are using the counter input T1 for the UVFault input.
Maybe UVFault could have gone to INT0 where it could trigger an interrupt when activated.

Last edited by squiggles; 11-28-2009 at 07:19 AM..
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