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).
Fuse systems for Lucas & Smith dynamos, discussing overheating (roasting) conditions.
| Identifier | ExFiles\Box 36\4\ scan 123 | |
| Date | 25th August 1920 | |
| X.3014b To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Bn.{W.O. Bentley / Mr Barrington} c. to Da.{Bernard Day - Chassis Design} EFC1/T25.8.20. X.2515. X.3014b. - FUSE SYSTEMS WITH LUCAS & SMITH DYNAMOS. X.295. X.3749. In answer to your telegram, there is no greater inherent tendency of the Smith dynamo, to roast than in the case of the Lucas; either machine will roast if the field be left on circuit so that the machine be allowed to run excited at a relatively high speeds, when not connected to a battery. Neither machine will roast sufficiently to harm itself under proper conditions. X.3957. On the standard arrangement of the Lucas system as going out on cars, there is a light field fuse only in the dynamo-battery system. This fuse is readily melted so as to dis-excite the dynamo if at any time it be run with the battery disconnected. There is no main fuse to cut off the battery from discharging through the dynamo, should the cutout stick on. Owing to the fact that Mr. Platford reported to me one or two cases in which the Lucas cutout had stuck on and allowed the battery to discharge, we arranged in the new experimental system, a main fuse in addition to the field fuse. Provided these fuses are of the correct size, there is still no possibility of the dynamo roasting itself. Should the main fuse be blown for any reason, the next time the dynamo is run up and switched on, the field fuse should Contd. | ||