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).
Letter to Joseph Lucas Ltd. regarding the testing and specifications of an LR7 regulator, model LT.1427.
| Identifier | ExFiles\Box 166\2\ img149 | |
| Date | 18th January 1938 | |
| Rm{William Robotham - Chief Engineer}/RO.{C. C. Rose - Export Manager}8/JH. 18th January, 1938. Messrs. Joseph Lucas Ltd., Great King Street, BIRMINGHAM. For the attention of Mr. Toulmin. Dear Sirs, With reference to the LR{Mr Ellor}7 regulator No.LT.1427 which you recently handed to us for test as a regulator embodying the latest ideas, we are pleased to say that this unit has given a satisfactory performance on the bench. Briefly, we obtained a difference between the cold and hot outputs at 15 volts, through terminal A1, of only about 1.5 amperes. In a similar manner a difference of about 2.5 amperes was obtained between the outputs at 15 volts through terminal A.{Mr Adams} The latter output (through A) still strikes us as being high, but we are prepared to see how it works out in service. In order to avoid confusion, we would like to record here the main features of this regulator as follows :- (1) Shunt winding of larger gauge wire, and less turns than previously requiring more current. Resistance about 7.5 ohms. (2) Larger capacity swamping resistance of 23 ohms value. (3) Ratio of swamping resistance to shunt winding resistance 3 : 1. (4) Contact points resistance of 63 ohms. (5) Bucking coil resistance of 38 ohms. (6) Contact points of tungsten. | ||