Injector Duty Monitor

[Chad Clendening]

What about making a SIMPLE PWM to DC converter for a DMM?  I figure this will
run about $2.00.  Maybee 3 if you have to go to a retail store.

Use a 10 volt regulator so the voltage is at a level most people can easily
divide in their heads.

Invert/ cleanup the PWM signal, using a bipolar setup as a common emitter, the
collector of that should have  ( near) 0 volts when the PWM is off, and near
10 volts when the PWM is on.  Connect this signal to the gates on both the
FET's. The drain leads of both fets are connected together in addition to a
filter resistor.  The source of the N channel is conntected to ground and the
source of the P is connected to +10.  The other lead of the filter resistor is
connected to a filtering capacitor ( this will also be the output of the
circuit) and the other side of the resistor is grounded.

The output of the circuit should be a 0 to 10 volt signal proportional to the
duty cycle x 10.  As long as the RC is correct ( big enough) , even a cheap
DMM should display the duty cycle OK

If this is too confusing I may be able to draw it in magic marker.

Chad