So I have this aftermarket cruise control in my car that uses the
speed signal from the car to set the speed. It does not use magnets on
the driveshaft. The cruise control only starts working above 35 mph.
Every cruise control I have ever used, factory or aftermarket, only
worked from about 35mph and above. But I do a lot of driving below 35
mph and want to use the cruise control for it. So I'm hoping that if I
measure the signal from the car with an oscilloscope it wil show
either a chain of pulses or a voltage that changes with the speed. I
looked online and found a couple frequency doubling circuits that look
like they would work. I'm sure that the extra pulses the circuit would
make must be evenly spaced between the pulses from the car for my
scheme to work. And at least one of the circuits I found appears to do
just that. If it is a rising voltage that I need to modify I'm not
sure how I would do that. What if the rise with speed isn't linear?
Anyway,any thoughts or advice? Any circuits that would work? Maybe a
chip to do all the work?
Thanks,
Eric