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).
The position and testing of various electric clocks for cars.
| Identifier | Morton\M19\ img002 | |
| Date | 2nd December 1930 | |
| To R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. Hor. R.{Sir Henry Royce} c. Mr. Ev.{Ivan Evernden - coachwork} PN.{Mr Northey} ORIGINAL EFC/AD2.12.30. X.6026. ELECTRIC CLOCKS FOR R.R. CARS X.6022. The position of electric clocks on R.R. cars is now as follows :- ROYCE. The original pattern clock referred to in our EPC/AD2.7.30 is still going satisfactorily on the old experimental chassis 9-EX. We have had one clock made up suitable for the present standard instrument patch and this has been put on Eg's car 58-GN and is, so far as our knowledge goes at the time of writing, operating satisfactorily. Three further clocks of this make have been obtained, made suitable (slightly larger diameter) for the rearrangement of instrument patch. None of these instrument patches are, however, available at present either on production or experimental cars. Two of these clocks have operated satisfactorily on bench test and await the opportunity of being placed on experimental cars. The remaining clock of the three failed to operate after satisfactory operation for a considerable time and was duly passed back to the makers who reported that they could find nothing wrong with it. They are, at present making a thorough investigation. We have put forward to the clock makers the view, based on principles, that these clocks should be arranged to stop on contact with battery disconnected and be of sufficiently low resistance to disallow any stopping on contact with the lowest battery voltage that might be experienced. We have reasoned that owing to the clock action being fundamentally a motor action, a lower resistance does not necessarily mean more consumption, without here entering into the detail of the argument the only objection we see to the application of this principle is on the score of noisier operation. We are arranged, therefore, with the makers who were interested in our views, to have two of the three clocks arranged with resistance sufficiently low to enable the clock to operate on five volts whereas with the normal winding the clock would not operate below eight volts. Experimentally we shall ultimately arrive at the best arrangement. | ||