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).
The speed ranges of a Crypto D.C. variable speed motor under different regulator settings.
| Identifier | ExFiles\Box 61\2\ scan0042 | |
| Date | 13th November 1928 | |
| X.75 13.11.28. RANGES OF SPEED OBTAINED ON CRYPTO D.C. VARIABLE SPEED MOTOR Using series and shunt regulators on the control board, in conjunction with those supplied with the motor. --- Supply voltage at control board terminals = 120 volts. Motor light. Control with both regulators. Both series regulators in and both shunts out. (strong field). 1300 r.p.m. Control with board regulators only. Series regulator in (strong field). 1350 r.pm . " " out. " 1780 " " " out, and shunt in. (weak field). 2740 " Control with new regulators only. Series regulator in (strong field). 1700 r.p.m. " " out. " 1750 " " " out, and shunt in. (weak field). 3060 " --- EFC/CAP. | ||