The Stovebolt Site Forums The Shop Area The Electrical Bay Generator/alternator tester

Some of our members have access to a lathe, and with a little creative tinkering, it's possible to rig up a pretty efficient way to drive a generator or alternator for testing. Just remove the lantern post tool holder, and fabricate a bracket that can be bolted onto the compound rest in its place. Then mount an old crankshaft damper or any other type of pulley into the chuck, add a belt, and you've got a variable-speed drive for a generator or alternator. Depending on how particular (or anal-retentive) you happen to be, a complete charging system can be simulated once the unit is spinning.
Jerry

Can you clarify what the reading on a multi-meter should be on the "A" and/or "F" terminals?

If the generator is polarized and spun without any wires connected, the "residual voltage" between the "F" terminal and the generator housing (ground) will be approximately 1/2 Volt DC. The "Arm" terminal will have approximately the same reading until the "F" terminal is grounded, then it will spike to 20 volts or more, depending on the speed of the armature. It's much better to use an analog meter with a sweep needle instead of a digital meter when working with a DC generator and a 3-unit magnetic regulator. Digital meters are too sensitive to voltage spikes and "noise", resulting in unintelligible gibberish instead of a good reading.

To get a good test, a battery, an ammeter, and a voltage regulator will need to be wired in to simulate a complete charging system.
Jerry