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).
Requirements for low-resistance chassis wiring to avoid voltage fluctuations.
| Identifier | ExFiles\Box 61\2\ scan0118 | |
| Date | 1st May 1919 | |
| To Ry. From EFC. c. to BH. c. to EY/HRO X.3374 EFC1/ATS.5.19. X.2778 - RE WIRING FOR CHASSIS. X.3374. We ought to make quite sure that a certain portion of the wiring in particular and the whole of the wiring in general, which, we understand, is to be supplied by Messrs. Lucas, should be of sufficiently low resistance. We refer in particular to the wiring connecting up the Switchboard and Distributor Board to the Battery. What we wish to avoid is too much change in the voltage of supply to the lamps etc., due to the Dynamo being switched on and off. Owing to the characteristic common to so called "constant current" machines by virtue of which the amperes delivered rise with the voltage of delivery (at dynamo terminals), the rise of voltage on the distributing terminals due to charging, is more than ever aggravated if there is any considerable resistance in general, and in particular between the battery and the point of junction of the dynamo and lamp connections to those of the battery. When the battery is fully charged and shows 13¾ volts on its terminals on open circuit and 15.75 on closed circuit (charging) we shall be delivering a current of 12¾ to 13¾ amperes in spite of the full state of charge, and this means that we may possibly have 16.25 volts or more at the board if only, say, one lamp is switched on. We should say half a volt difference ought to be the limit, which means that the particular conductors mentioned should have a (Contd). | ||