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).
Continued discussion on the design and differences of an auto switch compared to the Midgley patent.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 150 | |
| Date | 17th November 1927 | |
| Contd. -2- EFCl/T17.11.27. and tail lamps for a smaller time) before letting the auto switch back to put the dynamo on charge again, but that on the sudden application of the headlamp load the momentary drop of voltage would be sufficient at once to put the dynamo back on charge. We see favourable prospect of this being possible and we are now experimenting to prove the possibility. The elimination of the series coil Simplifies the auto switch considerably, It has then only two windings (one a resistance winding) and four terminals. The last element of similarity to the Midgley switch is eliminated. The auto switch now differs from the Midgley in five respects - (1) The use of a much larger resistance to bring about a much greater reduction in the charge, in fact practically to switch off the charge altogether. (2) The different connection at the negative end of the shunt coil of the auto switch. (3) The winding of the resistance itself on the core. (4) The use of two rigid contacts instead of one spring supported contact. (5) The elimination of the headlamp series coil. In this form it would appear to steer quite clear of any Midgley patent. Further,it would appear to lie rather to one side but roughly between the two extremes of Bijur type vibrator regulator on the one hand, and Midgley type auto switch on the other. It thus is of interest to | ||