Gene Harper Solid State Regulators

[DEEBS47Chief1991]

I also found this info about a model T generator that is similar to the circuit. The generator internal wires look like what you described.

model t 2 wire.jpg

[DEEBS47Chief1991]

This looks similar to an Indian cut-out type regulator circuit.

Model T 1 wire config.jpg

[PRG]

Howdy sir,

PODtronic: red-battery, black-ground to generator body and then frame/battery ground connection, yellow-armature brush, green-field coil (negative). Remove third brush assembly, attach one field coil wire to armature brush. To ensure proper direction of rotation, ie, your field coil wires connected correctly you’ll need to “motor” your generator before connecting regulator. Attach alligator clip wire from battery positive to armature wire, attach negative to green destined field coil wire and another ground to generator body. If it motors opposite direction of rotation when installed in machine, merely switch field coil wire connections. A “high output” Autolite is well within the operating limits of a POD, don’t think I’ve seen one put out more than 12 amps, and that was when cold,

[gharper]

Looks like you have the diagram correct, and matches what PRG is telling you. One note, the high output Autolite was rated at 18 amps, 7 volts, so just beware. I've seen a few that could do it, especially if rewound and converted to 2 brush. The safe thing to do is reduce your lighting loads by using LED's.

[DEEBS47Chief1991]

Thank you Gene and Peter for educating me. This is fascinating information. I have already installed LED bulbs and electronic ignition in my Chief so the amp draw is minimal.

However, I do have another question: Why does an Auto-lite High Output generator with a TC regulator still have a 3rd adjustable brush? The TC regulator regulates the voltage. Why would you need an adjustable third brush?

DSCN2829.JPG

[gharper]

The term "TC Regulator" is a misnomer, for sure! Accurate voltage regulation back in the day required a large, complicated and expensive mechanical regulating system. Larger cars and other big equipment used these, but most motorcycles did not. The evolution was first, a simple 3 brush generator. By setting the 3rd brush at a given location, that would limit the current output at a fixed amount, but there was no regulation of the voltage output. So, big batteries were installed which acted as a voltage regulator, burning up the higher voltage in the form of heat and gas.

A fixed charge rate was great if the load was constant. If you ran with lights on all the time, or never, it could be set to that load. Any deviation from that caused an under, or over charge condition. The next step was a 2 charge system, a high and low output setting that attempted to match loads when running with lights on or off. Harley did this beautifully with the 32E generator, starting in 1932. That system was quite efficient and simple. I'll save that explanation for a different topic. Starting in 1938 (as an option) Autolite had their solution, hence the TC, or Two Charge designation. The design was not as simple, efficient or clean as Harley and required much maintenance. In a nutshell, the Autolite system used the 3rd brush to control field voltage, for a fixed output. They then added a second relay that would close at high battery voltage and insert a large carbon resistor into the field circuit, burning up power in the form of heat and thus dropping field voltage and the charge rate. Again, no true voltage regulation, other than the battery.

So, to answer your question: Both the HD 32E and Autolite TC generator systems used the 3rd brush to set both the high and low charge rates at a fixed amount. Moving the 3rd brush would change both high and low rates at the same time. Again, a simple and cheaper system compared to the more complicated big regulators.

I'll say this again, HD was light years ahead with the 32E design. It didn't waste excess power, as did the Autolite and didn't have a second relay to mess with. The TC regulator was prone to breaking the carbon resistor, which resulted in a constant overcharge. Also, the mechanical relay required constant maintenance and adjustment.

[dukekleman]

Well put and nicely stated Gene!

Duke

[DEEBS47Chief1991]

Thank you Gene. That answered the question perfectly. Did anyone back in the day try to convert an Autolite to a 32E type regulator for better (automatic regulation) performance? Having that manual third brush is a pain if you like to run lights at night and no lights during the day.