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 description of the operation of the dynamo regulating range, cutout unit, and solenoid-operated starter motor.
| Identifier | WestWitteringFiles\J\December1922\ Scan91 | |
| Date | 30th December 1922 | |
| -2- Contd. of the carbon contacts. In the second stage of the regulating range which goes up to any speed at which the dynamo is driven, the field winding is momentarily connected in parallel with the series winding of the regulator and again disconnected in rapid sequence. The cutout has the usual shunt and series coils and an additional contact which allows the supply of current to the push button switch and lamp indicator on the switchbox only when the dynamo is not charging. this conn- ection of the cutout unit being labelled 59. The starter motor has housed in its end cover a solenoid operated main switch. The starter motor has two field windings, a main and an auxiliary. When the dynamo is not running and the starter push button is depressed a supply of current from the battery traverses the principal coil on the solenoid switch, auxiliary field and the motor armature, and causes the motor to turn slowly. In the meantime the magnetic drag is moving the whole armature axially so as to engage the driving pinion. At a certain point in this motion a catch is operated which allows the main switch to be drawn on by the solenoid and supply a full current to the motor field and armature. There is an auxiliary coil on the solenoid taking a small current in an opposing direction at the full voltage of the battery. This only produces sufficient ampere turns to allow the solenoid to let the main switch off when the speed of the starter motor | ||