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).
Road tests of the electrical auto-switch and charging system for various chassis.
| Identifier | WestWitteringFiles\Q\February1927-March1927\ 92 | |
| Date | 15th March 1927 guessed | |
| -3- Contd. The reduced output continues in operation until a stop is made or the headlights are put on. If a stop is made with a subsequent start, the process is repeated. If, while on reduced charge the headlights are switched on, the opposing ampere turns of the series coil due to the headlamp current enable the auto-switch to go back on contact and full output is given. On switching off the headlights full output may continue for a short period, after which the auto-switch again operates. The reports of the actual tests on the road are as follows :- "On 20 HP. Chassis 9-GIII. Starting with the battery standing at 12.5 volts, open circuited, the car was run with dynamo charging at its maximum rate until the voltage (measured at the switchbox) reached a value of 16.0, the output being 10.0 amperes. At this point the controller operated reducing the figures at once to 14.8 volts, 5.0 amperes. After this the voltage rose to 15.1 in further running but did not exceed this amount. Ignition current has to be added to all the above ampere readings. These operating figures were repeated consistently two or three times, the engine being warm throughout. There were signs of slight uncertainty of contact before the device actually operated. The headlamp current was always sufficient to restore contact after operating. "On 40/50 HP. Chassis 8-EX. A voltmeter, connected to the inspection lamp terminals, read the voltage of the system, the ampere output being measured by the chassis ammeter. The results and the conditions under which obtained were as follows :- Contd. 2907 [Left Margin Text] ORIGINAL COPIES LOCKED P.A. | ||