The project is a tachometer for a watercraft using a MSD total loss ignition. The MSD
provides a wire to drive a tachometer. The signal from the MSD is a 12v, 20% duty cycle.
The project is nearly complete, except I am not sure how to connect the Propeller to the
tachometer wire. I have been thinking of using a voltage divider, or possibly a voltage
divider with a 1k resistor before the propeller pin.
My first problem is the watercraft is 250 miles away. I am trying to build it, and then let
my friend install it. I have thought about trying to simulate the MSD signal with a pnp
transistor controlled by a Propeller. There is simulation software available in the obex
that I should be able to modify to use a transistor, but frankly I am worried that my
idea of a circuit may be to simple? and endanger the Propeller.
Any help is greatly appreciated.