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 an electro-magnetically operated relay switch for a dynamo-battery system.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan210 | |
| Date | 12th June 1926 | |
| EFCL/T12.6.26. -10- Contd. One other case only of a compromise between the two systems will here be referred to, but one which would appear to be an extremely satisfactory compromise between the two extremes. In this case also a dynamo of the usual so-called inherently controlled type is used and a resistance provided which again is inserted into the field excitation circuit, and which is automatically short circuited at appropriate times. It is in the method by which the alternate short circuiting and open circuiting of this switch is carried out that the difference lies. In this instance, the switch referred to is an electro-magnetically operated relay switch, the switch action taking place between contacts similar to cutout contacts, and between which contacts there is a definite switching "on" and "off" action and no suggestion of vibratory action. The arrangement of the switch is such as to be "on" until it is opened by electro-magnetic action. This relay switch is definitely arranged in such a way that it requires considerably more ampere turns of excitation to open the switch than the amount to which these ampere turns must be reduced again to allow the switch to close. There are two excitation coils on the magnetic core of this switch, one of which is a pure volt coil operating directly from the voltage of the system, and the other of which is a coil in series with the supply to the load on the dynamo-battery system, i.e. excluding load of battery itself on dynamo, and starter motor load, the ampere turns of which Contd. | ||