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).
Requirements and comparative analysis of car dynamo systems.
| Identifier | Morton\M22\ img023 | |
| Date | 11th November 1918 | |
| To EFC. from R.{Sir Henry Royce} Copy to EH. " " BY.{R.W. Bailey - Chief Engineer} " " BJ. ORIGINAL 13 NOV 1918 RE CAR DYNAMO. 4 11th November, 1918 R12/G111118. X. 3231 X. 3014 X. 3374 (1) I do not think the system adopted by Rotax, Leitner, Lucas, and others, gives the lightest form of generator, because to get a system of regulation by windings, appears to require either an inefficient dynamo or certain parts within the dynamo which are not contributing towards effective output. (2) In the Bijur and similar systems where there is plain shunt winding and separate voltage regulator, the machine can be built on the most economical and efficient lines as regards weight, and can give maximum current at the lowest speed it will cut in, whereas with the Lucas and C.A.V. systems, only a small current is obtained at first, increasing with increased speed. (3) We must have enough current to maintain necessary lighting (and dynamo must cut in) at 15 miles per hour, i.e. 750 r.p.m. of dynamo (does Sales agree this is correct ?) (4) Find out from London what is the usual c.p. of the lighting of ordinary cars of R.R. 40/50 size, i.e. the watt required for efficient driving. (5) Cannot agree to fitting regularly a dynamo and regulator weighing more than 40 lbs. unless it is absolutely necessary. X. 3405. (6) Re system described in "Electrical Review", let us make an estimate of advantages of this new system before attempting to construct one. If it makes a heavy machine as suggested in (2) then I am not in favour. (Contd.) Mr Cowen C. | ||