Using the V-Reg dynamo regulator
with a 'Bosch' type dynamo
Use of the V-Reg Dynamo regulator on 'Bosch' type dynamo.
The V-Reg Dynamo regulator is designed to be used with
Dynamos having Lucas configured wiring ie E3L. This Lucas wiring has
the Field coil in the Dynamo connected to earth as opposed to the
'Bosch' system which has the Field wiring connected to the Armature or
D output terminal. This Bosch system is used on BMW, MZ, Urals and
Ducati and most Russian, Italian, Chinese machines. Another user
of the 'Bosch' system was the first electronic regulator from JG in the
1980s, this was a long grey cast alloy box with three wires and was the
first real attempt to get 12V from the E3L. The V-Reg regulator can be
used with most of these 'Bosch' dynamos provided certain criteria are
covered and the internal wiring of the Dynamo is changed to the 'Lucas'
configuration. (Harley Davison uses 'Bosch' BUT invariably they
generate more power than the V-Reg is designed for.)
To use the V-Reg on any other dynamo than a Lucas E3L type you must comply with this specification.
The Dynamo you are using is not capable of generating more power than
the V-Reg can control, for the standard V-Reg this is 100W (there is a
higher output [car] 150Watt regulator)
The Field winding in the Dynamo must not be less than 3 ohms.
The configuration within the Dynamo must be Lucas.
The fitting instructions with the V-Reg give a circuit diagram of the inside of a Lucas Dynamo, this is what you must achieve.
In most cases you are advised to move the Field
connections to obtain Lucas, but occasionally by inspection you can see
it would be easier to move the brush connections. It is the
relationship between these windings that is crucial.
Open the Dynamo end cap and locate the two Field wire
connections, they usually disappear inside the case. Disconnect
them and move BOTH the wires. The one that was on the output D (or D+)
terminal must become connected to the F terminal. The wire that WAS on
the F terminal should then be connected to EARTH within the dynamo.
You must move both Field wires to retain the relationship between the Field and the Armature.
Now please re-polarise the Dynamo and test for output (with a lamp) as
per the instructions with the V-Reg. If for some reason you do not
achieve an output then please check your work and perhaps resort to a
Multimeter to check resistances.
21 October, 2009