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).
The theory of operation for the T. & M. Dynamo.
| Identifier | ExFiles\Box 3\5\ 05-page007 | |
| Date | 1st October 1911 guessed | |
| Theory of the T. & M.{Mr Moon / Mr Moore} Dynamo. In order to clearly follow the action of the machine the various connections and arrangement of pole-pieces and brushes are shown diagrammatically in Fig. 1. The main brushes are shown in the neutral position at A and B, each being connected respectively to an auxiliary brush half a pole pitch or 90° in advance, i.e., at A' and B' by means of resistances R and R'. As the armature C begins to revolve between the poles D and D', due to residual magnetism an E.M.F is set up between the brushes A and B, which has the effect of sending a current through the shunt winding S S' thus building up the shunt field, and it also causes currents to flow in the resistances between the main brushes and the auxiliary brushes and in the armature conductors lying between the brushes A A' and B B'. These currents produce a magnetic flux in the armature parallel to a line connecting a main and auxiliary brush, and its effect is to strengthen the main field. This state of affairs continues until the armature is revolving at a sufficiently high speed to generate the line voltage between the main brushes, which represents the cutting-in speed of the machine. 1 | ||