Rolls-Royce Archives
         « Prev  Box Series  Next »        

From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Description of the C.A.V. Dynamo Voltage Regulator for the 40/50 and Bentley Chassis.

Identifier  ExFiles\Box 60\3\  Scan252
Date  18th October 1933
  
86044
By/NHW. From Hs{Lord Ernest Hives - Chair}/Wst.
c.c. to Cx.{Major Len W. Cox - Advertising Manager}
Hs{Lord Ernest Hives - Chair}/Wst.1/MA.18.10.33.

C.A.V. DYNAMO VOLTAGE REGULATOR ON 40/50 AND BENTLEY
CHASSIS.

We attach herewith some notes on the above for your guidance in connection with the Instruction Books.

Description of regulator.

The regulator consists of a small circular unit mounted with a resistance on a common base on the dashboard. Its operation is on the vibrating contact principle. A rod or a plunger, carrying a contact point at each end, floats on two springs (one at each end) inside a solenoid. Normally it rests with the point at one end, in contact with a third point which screws into the cylindrical case, and is electrically connected to the negative terminal of the dynamo. The rod itself, is electrically connected to the case which forms the junction of the dynamo field winding and the field resistance. A fourth contact point similar to the third, screws into the opposite end of the unit and is electrically connected to the dynamo positive through the series winding of the regulator. The solenoid carries the usual two windings - shunt and series. As the dynamo terminal voltage rises, the plunger moves under the influence of the shunt winding thus opening the two contacts which are normally together and inserting resistance in the field circuit. This lowers the voltage, and the springs return the plunger to its former position. In this manner the plunger vibrates until a speed of the dynamo is reached where the contacts remain apart and the resistance remains in circuit. As higher speeds are reached the plunger moves further along and makes contact with the fourth point. A vibrating action occurs here also, so that the field winding is intermittently short circuited. The series winding assists the shunt when the dynamo is delivering current, and is adjusted to operate at the desired output.
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙