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).
Testing procedures for a dynamo and distribution box, detailing voltage, current, and resistance parameters.
| Identifier | ExFiles\Box 163\6\ img064 | |
| Date | 16th October 1931 guessed | |
| -2- dynamo, a 12 volt battery of suitable capacity, two ammeters A and B, and two voltmeters V and v, according to diagram herewith, the latter voltmeter having a loose lead suitable for touching on terminal A of the distribution box when required. (4) The distribution box being in a cold condition, the dynamo shall be driven at gradually increasing speed until the cutout is just operated. The instant of operation will be shewn by a movement of the needle of ammeter A.{Mr Adams} The readings of the voltmeter V and ammeter B, immediately preceding this instant, shall be noted. The former shall lie between the limits 12.2 and 12.8 volts, and the latter shall not exceed .20 amperes at 12.5 volts, i.e. shunt coil resistance must exceed 62.5 ohms. If the cold operating voltage does not fall within the specified limits, a slight adjustment of the control spring of the contact lever should be made. (5) The dynamo shall now be speeded up to allow a charging current of 15 amperes to flow into the battery for a period of 5 minutes. At the end of this time the loose lead of voltmeter V should be touched on terminal A when the reading must not exceed .35 volt and the points must show no sign of undue heating. | ||