Here you have a Brand new Boyer Bransden power box, this kit is designed for bikes with fitted with a single Phase Alternator, running on a 12 volt positive or negative earth set-up


Why fit a power box?

  • More stable voltage protecting from overcharging (with battery fitted), replacing the need for a Zennor Diode.
  • Works with Electronic or standard ignition set-ups
  • Easy 6 to 12 volt conversion 
  • Save weight
  • improve lighting
  • Delayed lighting start


Power Box is a self regulating rectifier with an internal current and voltage storing capacitor.

Connecting directly to the alternator, the output is approximately 15 volts with no current being drawn and 14.5 volts with some load. These values are just right for charging a 12 volt battery or running the electrics direct.

The unit has been designed using the latest power technology semi-conductors to provide stable, direct current from standard permanent magnet alternators.

Three types are available: Single phase, Bi phase and Three phase.
Some are available with a charging lamp control, or lighting delay circuit, which prevents the lights being turned on until after the engine is started.

Ensure you have the desired unit before fitting, Single phase and Bi phase units control 200 watts and three phase units control 300 watts.

As a rule of thumb Single phase power boxes are suitable for use with most British Bikes, pre 1975 with alternators two, or three wire. Bi phase are suitable for use with most Italian and French machines equipped with three wire alternators. Three phase will suit some British machines post 1975 with three wire alternators and the majority of Japanese three wire machines.


This item is made by Boyer Bransden electronics LTD.

Please direct any technical questions directly to them

We do combine postage, and will refund any large over payment (£5+) once the item has been dispatched.

This is due to the massive range of products we produce and sell, in all shapes, sizes and weights, its imposable for us to price accurately for all product combinations.

We can provide an exact price for a combination prior to purchase upon request.