Solid State Voltage Regulators For 3 Brush Motorcycle Generators




Solid State Voltage Regulator for High Output Autolite GDE Model Generators


APPLICATION:  This solid state voltage regulator is designed specifically to fit high output three brush GDE model Autolite generators using a 6 volt negative ground system and external TC model regulators. This generator and regulator combination was standard equipment on all Indian motorcycles from 1948 through 1953 and available as an option from 1938 through 1947.


CONSTRUCTION:  The solid state regulating components are permanently mounted inside a powder coated aluminum housing which is CNC milled to look exactly like the original stamped cover. The housing also acts as a heat sink for the internal components.  The riveted ID tag is stamped with the correct model and year of manufacture to fit your specific machine. This housing is mounted on a cadmium plated reproduction of the original base.  Units can be supplied in either single or double terminal configurations depending on your application.  The end result is a reliable, maintenance free, modern electronic regulating system housed in an exact replica of the original TC style regulator.


OVERVIEW OF OPERATION: Installation will eliminate the often troublesome three brush regulating system and the mechanical cutout relay and regulator. It will be replaced with a solid state current and voltage regulator permanently mounted inside the unit. The solid state regulator will allow complete and accurate current and voltage regulation of the generator thereby maintaining proper battery charge at all times. Maximum output voltage will be limited to approximately 7.25 volts. Current output will vary automatically, based on demand, from approximately .75 amps up to the maximum allowed by the generator, approximately 20 amps.




  1. A properly functioning Autolite model GDE generator configured for Negative Ground Operation Only

  2. Elimination of the third brush inside the generator, converting it to a two brush system.



* 6 volts DC nominal, 7.25 volts maximum output

* 20 amps continuous, 25 amps max, intermittent use

* Negative system ground

* Negative field winding control

TESTING: This regulator has undergone extensive bench and field testing over the last 4 years.  Prototype units have been in service on Indian Chiefs and 4cylinder machines with excellent results reported. The battery ignition Indian 4 cylinder is the ideal application for this regulator. The battery ignition 4 cylinder generator turns only at engine speed, which limits adequate generator power output to high engine RPM conditions (3000 RPM and above). By controlling field voltage the regulator will allow maximum generator output at much lower engine RPM ranges (15 amps at approximately 1800 RPM was obtained during prolonged bench tests)

PURCHASE PRICE; U.S. $300.00 each (plus shipping).  Price includes one complete unit ready to install and detailed installation and operation instructions. ID tag will be stamped to represent the correct model and serial numbers for your specific application.

Please specify year and model of motorcycle and if equipped with either an ammeter or indicator light.

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