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).
Page two of a letter discussing performance issues and requirements for a dynamo voltage regulator.
| Identifier | ExFiles\Box 166\2\ img003 | |
| Date | 6th September 1935 guessed | |
| -2- In addition to the voltage characteristic being a rising one as indicated above it was also excessively irregular. This we think is a matter for better spring and magnetic circuit arrangement and adjustment. On reducing the speed of the dynamo it was found that the armature regulator locked [handwritten: lagged] on the return movment, i.e. it was prone to remain down after the voltage on the terminals was reduced just as though the residual magnetism in the circuit was excessive and the resultant tractive force was too strong for the spring to overcome With regard to the series winding of the regulator we require this to be so proportioned that with a terminal voltage of 13 it will regulate at a current of 24 amperes approximately. In conclusion we may say that we like the principle of progressively increasing resistances, but it was found, however, when made to work at 16 volts both the shunt winding and the resistance unit attained rather excessive temperatures. We have not tested the cutout as yet our attention being mainly devoted to the regulator performance. It is hoped, therefore that with the above information you will be able to produce a regulator more in accordance with our requirements. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||