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).
Report page detailing the operation of various generator and voltage regulator systems.
| Identifier | ExFiles\Box 31\1\ Scan050 | |
| Date | 31th December 1919 | |
| Gr{George Ratcliffe} 1K 12/31/19. 6. Contd. The generator used is a plain shunt wound machine, mounting a regulator of the vibrator type. The voltage is kept constant as the speed of the car changes, by inserting resistance in the shunt field of the generator varying in degree the exciting current. The voltage regulator consists essentially of a resistance, two contact points, each of which is connected to a terminal of the resistance; a magnet which is excited by current from the generator. The two contacts are held together by a spring so mounted on a lever of magnetic material, which is subject to the pull of the magnete. At all speeds below that which this generator develops the desired voltage the contacts remain closed. As the speed increases the voltage rises, and at a pre-determined setting the contacts open by the increased pull of the magnet, inserting resistance into the generator field. This immediately lowers the voltage and the magnet loses its strength, the contact lever returning to the closed position. As the voltage tends to rise again the whole action is repeated with a rapidity invisible to the eye. The regulation obtained is over a wide range of generator speeds The generator is usually designed to run at engine speed or higher. CONSTANT CURRENT GENERATOR: The constant current generator with vibrator regulator has some of the good features of the Constant Voltage and Third Brush Generator Systems, but differs somewhat in respect to charging rates when high speeds are maintained, having a characteristic curve with maximum charging rate, reached and maintained above a certain speed, whereas the Third Brush and Constant Voltage machines can be designed to decrease the charging rates at higher speeds. This system is very little used. CONSTANT VOLTAGE AND CONSTANT CURRENT SYSTEM: A system as above so far has only reached the experimental stage, and as mentioned earlier in this report, is under consideration by the Pierce-Arrow Co. Buffalo. I do not see any series difficulties to perfect such a system which from a theoretical point of view is an advance towards the ideal system. The apparatus under test for the Pierce-Arrow Co., comprises the plain shunt wound generator, vibrator coil inserted and suitably connected in both the voltage and current circuits. Gr.{George Ratcliffe} | ||