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).
Continued technical note explaining the effects of advancing and retarding brushes on motor and dynamo output.
| Identifier | ExFiles\Box 61b\3\ scan0152 | |
| Date | 18th February 1922 guessed | |
| -2- Contd. (1) If the control brush only be advanced, the output is reduced and vice versa, (because the span of the field winding is reduced thereby). (2) If the main brushes only be advanced, the output is increased thereby and vice versa, (because by this means, not only is the strength of the main field increased, but so also is the span of the field winding on the commutator). (3) If, however, all the brushes be advanced together, the net effect is to reduce the output, although the span of the field winding remains the same, because (1) brings about a greater reduction than (2) an increase. (4) Likewise "advancing" the commutator has precisely the same effect as advancing all the brushes. The above should enable us in future to avoid any ambiguity as regards the meaning of the terms "advance" and "retard" of the brushes and the commutator of motors and dynamos. EFC. | ||