[Mike Betts]

Chuck,

The following is not perfect but you don't need a load sensor to do it...

In your motor/generator pair:

(1) Make both the motor and generator the same type of motor.

(2) Wire a power resistor across the generator's electrical "outputs". Be careful to size the resistor properly.

(3) Measure the voltage and current at the "input" and "output". Also measure the speed at the spindle/coupler.

(4) Adjust the input voltage to a known value (in our case it's almost always 12.0V). Note that you do not need a precision high current power supply... Just use an Exide SLA and let it slowly discharge as you run the MG and take your readings at 12V.

Note also that you can ignore (4) depending on exactly the type of data you are going for...

For a given load resistance, you will take your readings:

Input Power (W) = Input Voltage (V) * Input Current (A)
Output Power (W) = Output Voltage (V) * Output Current (A)
Mechanical Power at coupler (W) = [Input Power (W) + Output Power (W)] / 2
Torque at coupler (N*m) = Mechanical Power (W) / Spindle Speed (radians/sec)
Power Lost in Motor (W) = Input Power (W) - Mechanical Power at Coupler (W)

et cetera...

Hope this helps...

Mike