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).
Methods for varying dynamo output, including manual control and bimetal thermostats.
| Identifier | ExFiles\Box 62\3\ scan0011 | |
| Date | 1st January 1930 guessed | |
| APC4/AD2.1.30 contd. -3- - dotted one is 14°. Such a pair of output curves would therefore be possible with twin control brushes in a twin holder, the adjacent tips of the brushes being separated by 3.1°. A possibility which has been suggested for varying output is manual control of the control brush advance and retard from the driver's seat. We recommend consideration of the possibility of bimetal thermostat control. We have been offered bimetal strips and hope to obtain samples. The forces involved to make or break contact are great and could be adapted to insert or take out field resistance within the carcase of the dynamo. The operating physical effect, namely dynamo temperature, and the apparatus to be operated upon viz. the field winding are together within the dynamo carcase. Alternatively the thermostatic force could be made to toggle over spring pressure from one to another of twin control brushes as described above. This would approach the ideal in giving more freedom in respect of the relative position of the two control brushes without danger of dynamo overheating on the major output. The writer possesses two examples of bimetal thermostats in connection with his domestic hot water system, one based on longitudinal differential expansion operating contacts in a relay circuit, the other on bimetal beam flexure differential expansion operating heavy (alternating) | ||