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Alternator Regulator


Alternator Regulator

We now have a new range of Regulator/Rectifiers for use with Lucas type permanent magnet (RM) alternators. These units replace the traditional bridge rectifier we have had since the late 1950s and the Zener diode (12V usage). In some cases of high-output alternators you might have been using two Lucas Zeners (Norton Commando MKIII) or a matched pair of Zeners (3 phase) or a triple Zener unit (Triumph).

A-Reg 1, for 12V, 200W capability.
A-Reg 6, for 6V, 200W capability.
A-Reg 3, for 3 phase, 200W capability.

Polarity and Connections

These units can be wired Positive or Negative Earth to the motorcycle. It is essential that the Positive and Negative output of these units meets the battery Positive and Negative exactly the same.

Connections are similar in that the YELLOW wires go to the alternator while the battery wires are the traditional RED + and BLACK -

They can be used without a battery but it is advised to use a Capacitor, (We can supply) especially if you have coil/electronic ignition (not essential if using magneto ignition). Be aware that with a stalled engine you no longer have lights, horn or stop light.

Full instructions come with each unit.


All three units have the same dimensions is 60 X 66 X 25mm with 6mm fixing holes at 55mm. Unit is best fitted to a flat metal surface (can be painted) as a basic heat sink.


I have always advised that the minimum capacity should be 5Ahr for any Classic British Motorcycle using traditional Lead Acid. Modern AGM batteries would appear to be acceptable.

Cyclon cells of 5Ahr or more are also usable.

What is not suitable is the 'square' 'dryfit' type with spade terminals (often surplus from burglar alarms). These will overcharge in due course and dry out.