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).
Page detailing endurance and destructive testing procedures for an ignition coil.
| Identifier | ExFiles\Box 69\1\ scan0282 | |
| Date | 31th December 1929 guessed | |
| -4- on 5.5 mm. secondary gaps at supply voltages of 10 and 8, also of the maximum speeds at which the distributor can be run for each voltage to maintain regular sparking. (10) With the coil at atmospheric temperature, the secondary output shall be connected to a suitable sphere gap voltmeter and measurement of the maximum secondary voltage put up by the coil under standard conditions with the 12.0 volt supply thus obtained. (11) The coil shall now be placed in an oven and run otherwise normally but at 17.5 volts for 5 hours during which time the oven is heated up to 100°C. after this time the performance at 12.0 volts on a variable subsidiary secondary high tension gap in series with the six main 5.5 mm. secondary gaps shall be noted. (12) An endurance test of 500 hours total duration shall be carried out on the coil with a supply voltage of 17.5 under standard conditions, the coil being given a two hours period of rest every 24 hours. (13) Assuming that the ignition coils have satisfactorily withstood all the above tests, and in order to find out the greatest weakness of the coil after the above treatment, a repetition of test (7) should be made for an indefinite number of hours until breakdown occurs, breakdown being made to occur, if necessary, by progressively increasing the secondary and primary sparking gaps. (14) The coil shall then be removed from its case and unwound for examination. | ||