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).
Bench testing an auto switch and noting unsatisfactory working conditions.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 49 | |
| Date | 27th October 1927 | |
| J.3 To R.{Sir Henry Royce} from EFC. c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. BJ. Wor.{Arthur Wormald - General Works Manager} c. PN.{Mr Northey} ORIGINAL EFC/T27.10.27. (Contd. from EFC/T25.10.27) AUTO SWITCH. X8780 X4008 When we first tried the auto switch on the bench we had the positive end of the shunt coil connected as shown in the diagram (full line) to distribution box terminal C and its negative end to distribution box terminal A - not as shown in diagram. With the auto switch set for a suitable voltage for normal running, we noted unsatisfactory working of three kinds :- (1) When accelerating the dynamo quickly, the auto switch (which breaks contact) would function (before travelling) before the cutout (which makes contact after travelling). Consequently there would be no period of full charge, but reduced charge would obtain from the start. N.B.1. This phenomenon would not take place on a slow rise of voltage, as a result of slowly accelerating the dynamo. N.B.2. Normal voltage holds auto switch off until charging switch is put off and voltage falls. (2) Upon switching the dynamo off and then on again, while running fairly fast, a similar phenomenon would take place - no period of full charge obtaining after re-making contact with the switch, though previously the system may have been running under the condition of full charge. Note:- It will be noted that these two effects are independent of the magnitude of the resistance R inserted in the field, until R is so large that the dynamo cannot maintain the cutout on contact, in which case a low frequency vibration (full travel) may take place. Contd. | ||