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).
Description of the ignition switch operations and details on the ignition coil, ballast resistance, and distributor unit.
| Identifier | ExFiles\Box 26\2\ Scan046 | |
| Date | 1st October 1919 | |
| Contd. -11- EFC2/T6.10.19. The upper portion of the switch is included in the battery ignition circuit and therefore in this position neither the magneto or the battery ignition is on. in the "M" position, the magneto connection is insulated and the two upper terminals are still disconnected from one another, hence the magneto only is in operation. in the "B" position the magneto connection is earthed and connection between the two upper terminals is made, hence only the battery ignition is on. In the "M & B" position, the magneto is insulated and the two other terminals are connected together so that both are put on at the same time. (l) IGNITION COIL & BALLAST RESISTANCE. A small compound plain ignition coil and ballast resistance in series with its primary is fitted to the front of the dash. The ballast resistance being of nickel wire limits the short circuit current of the coil to a reasonable value should the ignition switch be left on, and the make and break happen to be in the "on" position. It also has the advantage of flattening out the currentconsumption curve of the ignition in relation to changes of speed of operation. (m) CONTACT BREAKER, DISTRIBUTOR AND CONDENSER UNIT. This unit is very much the same as on pre-war R-R chassis, except that it is so modified to suit the non-trembler ignition system now fitted, this necessitating the addition of a small mica plate condenser which is connected as near to the contact points as possible, for the best effect. Contd. | ||