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 double circuit breaker from a Marmon car for chassis electrical circuits.
| Identifier | Morton\M1.7\ img005 | |
| Date | 3rd December 1921 | |
| To R & E.{Mr Elliott - Chief Engineer} from EFC c. CJ. & FN. c. Ev.{Ivan Evernden - coachwork} & KP. c. Rg.{Mr Rowledge} & Da.{Bernard Day - Chassis Design} c. R.R. of America Inc. ORIGINAL EFC/T3.12.21. RE CIRCUIT BREAKER FOR CHASSIS ELECTRICAL CIRCUITS. The double circuit breaker from the Marmon car is being sent to you for your information in connection with the Connawk electrical system. This consists of two units, one of which is a series operated buzzer between the battery on the one hand, and the dynamo and lights on the other. The other one is a series operated circuit breaker between the battery on the one hand and the tonneau light, then inspection light on the other, the only difference between this one and the first unit being that this latter has in addition a shunt coil across the contacts which allows the circuit breaker contacts to be held apart without buzzing when a ground occurs on any of the leads to these particular circuits. We cannot at the moment glean their reason for using two instruments. It would appear that one instrument should be sufficient. A current of 32 amperes through either series coil would provide sufficient magnetic attraction to cause the contacts to separate. In the case of the first instrument, the separation of the contacts of course breaks the circuit and the buzzer action ensues. After the circuit has been broken by 32 amperes, the current necessary to keep the contacts just dithering is only 24 amperes average. Contd. R.R. 886A 100 (T) (S.H. 798. 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2947 | ||