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).
High and low speed sparking characteristics, resistance values, and milli-ampere readings.
| Identifier | ExFiles\Box 48\3\ Scan084 | |
| Date | 27th July 1930 | |
| -5- Contd. (15) High speed sparking characteristics :- Regular sparking takes place at all high speeds, for advance on 7.5mm gaps, central 7.5mm, and retard 6.5mm. With lever advanced, shorting any one gap does not affect other sparks, but at central and retard, the spark following the shorted gap is extinguished. This is the case at all high speeds, the sparks otherwise appearing quite equal. (16) Low speed sparking characteristics :- Speeds :- (a) 430 r.p.m. (b) 380 r.p.m. (c) 270 r.p.m. (17) Flinging of contact breaker at high speed :- (18) Primary resistance :- .51 w at 18°C. { Inst. 98. 1.5 volt range 1.5 amp. range (19) Secondary resistance :- 2,400 w at 19°C. { Inst. 98. 1.5 volt range. (20) Secondary milli-amperes :- Inst. 22596. m.a. range. Horizontal position :- 13.6. Vertical position :- 8.1. Contd. | ||