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).
Specification sheet detailing electrical resistance, point gaps, and contact breaker timings for a component.
| Identifier | ExFiles\Box 48\2\ Scan080 | |
| Date | 8th March 1921 guessed | |
| -6- Contd. (18) Primary resistance :- .318 w at 16.5°C Instrument 98 on 1.5 volt and ampere ranges (19) Secondary resistance :- 12000 w at 16.5°C Instrument 98 on 15 volt range (20) Secondary milli-amperes :- Instrument 22407 on m.a. range Horizontal Position :- 3.9 inch poles of magnet across armature Vertical position :- 1.9 (21) Platinum point gap :- .014" (22a) Platinum point gap :- .018" Contact breaker timing :- (Table 1) A. {Mr Adams} Make. 14° Break. 90.5° R. {Sir Henry Royce} Make. 66.5° Break. 141° (Table 2) Retarded. Advanced. Make. 67° 15° Break. 140° 90° Make. 244° 193° Break. 322° 269° Make ratio :- .425 (N.B. Automatic (32.5°) advance subtracted) Contd. | ||