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).
Explanation of the ammeter's function and wiring in relation to the junction box and switchbox.
| Identifier | ExFiles\Box 26\2\ Scan048 | |
| Date | 16th October 1919 | |
| Contd. -13- EFC2/16.10.19. the junction box to the switchbox by means of two cores of a three core cable, the positive connection passes direct to the positive terminal on the switchbox, the negative connection is taken aside and made to pass through the weston ammeter on the instrument board before being connected to the negative terminal on the switchbox. the third core of the three core cable mentioned, leads back from that terminal of the ammeter connected to the negative terminal of the switchbox, to the main negative terminal of the junction box. thus it will be seen that all current used by the battery which is either taken from the switchbox or the junction box, must necessarily be indicated on the weston ammeter, also that the charging current to the battery mustalso be indicated by this instrument. If the ammeter needle moves over to the left, the battery is discharging; if it moves to the right, the battery is being charged, Exactly what current is charging or discharging from the battery is shewn by this ammeter at any moment. If the dynamo is running and no lights or auxiliary appratus are in use, the ammeter will indicate the out-put of the dynamo. If the dynamo is switched off and any lamps or other auxilliary appraatus are switch/on, the ammeter will indicate on the other side what amount of current these are drawing from the battery. if, dynamo, battery and lamps or other auxiliary appraatus are all on at the same time, the ammeter will indicate the difference between the supply current from the dynamo and the current demanded by the lamps or other apparatus, and will shew by the side to which Contd. | ||