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).
Description of a voltage regulator circuit and its components for controlling dynamo output and battery charging.
| Identifier | ExFiles\Box 61\2\ scan0176 | |
| Date | 16th December 1920 | |
| R.R. 825a (100 T) S.H. 798. 16-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2947 -4- Contd. is to reduce the number of demagnetising series turns, and, as a result, to increase the output of the dynamo. The actual results obtained from a machine are well shown in Fig.3. The arrangement of the circuit is shown in Fig.4. A close examination of the diagram will show that the Voltage Regulator has two fixed contacts. In the normal position of the vibrating armature, the shunt resistance is, of course, short circuited. When the regulator commences to act, this resis- tance is intermittently inserted in the shunt field winding. If the voltage continues to rise, the armature makes connection with the lower contact, thereby placing the series and shunt field windings in parallel. This is practically equivalent to short circuiting the shunt, and reduces the magnetisation of the field sufficiently to keep the voltage within the required limits under the worst condition. The arrangement also reduces the sparking at the contacts to an insignificant amount. The Volt Regulator, a section of which is shown in Fig.5 is mounted on the commutator end bracket, as also is the cut-out. Both will be seen in Fig.1. The cut-out is the standard "Bleriot- Phi" compensated type, which was described in "THE ELECTRICIAN" of 1920, October 29th. A section of the instrument is given in Fig.6. The arrangement of the circuits, and the method of control adopted fulfils the following requirements. 1. The charging current is governed by the state of the battery at any moment, and overcharging cannot occur as the current is automatically reduced when the battery voltage exceeds | ||