Manufactures Part number: 111A

V-Reg II (Dynamo Voltage Regulator)

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This is a solid state encapsulated regulator for motorcycles using the Lucas E3 type dynamo. The NanoContols dynamo regulator is designed to replace the mechanical regulator with modern reliable semiconductors, and can handle up to 100W (requires good cool airflow) at 6V and even more for the 12V version, provided the dynamo is capable of delivering this power. The regulator must be used with a known good automotive battery (minimum 5Amp-hours) and is guaranteed, subject to correct fitting and use with a known good dynamo.

The V-Reg II is an upgraded version of the original V-Reg. New features include:

Voltage & Polarity

 WARNING Ensure you fit a regulator of correct voltage and polarity

As manufactured all regulators are set to operate at 6V. For 12V operation the small GREEN wire loop should be cut and sealed (with epoxy or silicone).

For 6V operation the GREEN link wire is intact
For 12V operation the GREEN link wire is cut and sealed


To maintain original appearances this unit may be fitted inside the original control box by first removing all of the contents (solenoids, points and resistors) or it may be mounted in any convenient corner, maybe in the top of a tool box, such that it has some protection from injury and weather. The unit is contained within a case 50mm x 42mm x 22mm.

Testing Dynamo & Polarising

To test the dynamo (before connecting new regulator) check internal wiring is as diagram A. Remove normal D & F bike connections and link D and F together, connect a 12V headlamp bulb from the linked point to ground. Run engine at fast idle, lamp should be bright. To ensure the correct polarity of your dynamo, for your bike, and the correct function of the regulator, it is advisable to polarise or 'splash' the dynamo. To do this disconnect the field (F) connection from the dynamo; take a wire from the live terminal of the battery and briefly touch the F terminal of the dynamo ensuring the battery is earthed (as per intended use). This establishes the fields' remnant magnetism which is required for correct start-up. Reconnect all circuits


New style regulator
-Earth +Earth


BROWN BROWN A: Ammeter (to battery)

The are multiple fixing options, M4 stainless steel hex screws may be placed in the 'T' slots on the case, these match the bobbin spacing within the original regulator box.

Old style regulator ...
-Earth +Earth


Old style regulator
RED BLACK A: Ammeter (to battery)

Fixing is via a stainless steel M5 stud which is not connected to the internal circuitry. An M5 self-locking stainless steel nut is provided, this requires an 8mm A/F spanner (2BA may be acceptable).

Internal Dynamo Connections

Internal dynamo connections Disconnect the battery before starting work. Ensure the dynamo internal connections are as diagram A. The four wires can be soldered to the original four terminals inside the control box if used in accordance with the adjacent wiring table or alternatively any suitable crimp connectors can be used to connect to the bikes' wiring. Taking into account proper practices to produce clean firm connections.



To check operation of the regulator measure the voltage across the battery, at rest the voltage will be around 6V or 12V depending on version, rising to around 7.2V or 14.5V once the dynamo is operating (2500 engine revs, headlight OFF). If the unit is fitted within the original regulator box the dynamo power handing is limited to less than the regulators maximum due to the restricted movement of cooling air, however it will comfortably handle the standard 60W dynamo. This unit is only guaranteed provided it is fitted and used as intended, any miss-connections can cause damage.

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Last modified: 13 March, 2017