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).
Letter to Everett Edgcumbe & Co. Ltd clarifying an enquiry about the operational range of a Warren Motor.
| Identifier | ExFiles\Box 165\4\ img068 | |
| Date | 26th May 1930 | |
| X 6023. EFC3/AD. 26th May, 1930. Messrs. Everett Edgcumbe & Co. Ltd. 117, Victoria St.{Capt. P. R. Strong} London, S.W.1. Dear Sirs, Warren Motor. We are much obliged by yours of the 23rd inst. but feel that the writer has not appreciated that the enquiry was specifically as to the extent of the range of speed over which the motor would remain in step in the circumstances only in which the applied voltage and frequency remain definitely proportional. It appears to us that the limit of slow speed working would be controlled by the increasingly greater relative effect of the ohmic resistances in the windings becoming appreciable, while that at high speed by the increasing effect of induced eddy currents. There would appear to be a definite range of speed over which the motor would keep in step with a strictly proportional variation of voltage and frequency simultaneously, and it is the extent of this range which we are anxious to ascertain. Yours faithfully, A.M.I.E.E. FOR ROLLS-ROYCE LIMITED. | ||