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).
Specifications and availability of Phantom old type machines for use as generators and motors.
| Identifier | ExFiles\Box 34\4\ Scan185 | |
| Date | 23th September 1929 | |
| X2048 To R.{Sir Henry Royce} from EFC. EFC4/AD23.9.29. Your R2/M17.9.29. We already have in use, two Phantom old type size machines with no control brush, and main brushes set to approximate neutral. One of these, with altered field windings, runs as a plain shunt generator of output when warm of 13.6 amperes, plus .65 amperes field current, at 19.2 volts, being induction motor driven at 1450 r.p.m. The field coils are of 23 S.W.G. Another we use as a motor which, with a normal amount of independent field excitation (at 16 volts) runs light on 50 volts armature, with an armature current of 3.1 amperes at a speed of 1565. The armature resistance inclusive of brushes is about .45 ohm, so that the back E.M.F. is approximately 48.5 volts at this speed. This seems about O.K. The field loading for a reasonable normal excitation is about 25 watts, calling for about half an ampere at 50 volts, and would mean a field winding of 25 times the resistance of the standard winding of 19 S.W.G. This would call for .018" dia. wire or No.26 S.W.G. We are arranging one machine quickly in this way for rough brake trial. We have several quite good non-standard armatures that we can use, also one carcase is available. We can provide one extra terminal to keep field and armature distinct for convenience of reversal, if desired. I think we could get these machines so arranged within the three weeks suggested. EFC. | ||