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 the switchbox, its components, connections, and operation.
| Identifier | ExFiles\Box 26\2\ Scan117 | |
| Date | 27th February 1920 guessed | |
| Contd. -3- SWITCHBOX. This is situated on the instrument board and contains the charging switch, lamp switches, dynamo field fuse, and automatic cut-out, also terminals for the dynamo, battery and lamp connections, and socket for an inspection lamp plug. One such plug is supplied with each chassis. The cover of this box is easily removable. The internal and external connections of the switchbox are given in the connection diagram (fig.57). The arrangement of lamp switches allows the use of the head and tail lamps without the side lamps, or the side and tail lamps without the head lamps, or all three sets of lamps, at will. The operation of the charging switch connects the field, control and negative leads of the dynamo together and to the fixed contact of the cut-out through the series winding of the cut-out. The movable contact is in connection through the ammeter with the negative terminal of the battery. The positive terminals of the dynamo and battery are permanently connected together in this box. In addition to the series winding which carries the main current, there is a shunt winding on the cut-out connected between the main positive and negative terminals of the dynamo. When the dynamo is run up with the charging switch on, current in this coil causes the automatic contact Contd. | ||