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 3 of a testing procedure for an ignition coil, detailing high voltage and endurance tests.
| Identifier | ExFiles\Box 69\1\ scan0280 | |
| Date | 8th January 1930 guessed | |
| -3- conditions allowed thus to remain for a period of 16 hours, following this the temperature of the coil shall again be arrived at from the measurement of the secondary resistance. (7) The coil shall now be removed from association with the contact breaker and distributor and subjected to an intensive test utilising a high voltage 50 cycle supply. In this test a 5,000 volt .30 microfarad condenser is charged through a 15,000 ohm resistance by a 50 frequency voltage of approximately 1500. The primary of the ignition coil is connected to the terminals of the condenser via a .005" parallel faced gap and the H.T. terminals of the coil are connected to a single secondary gap of adjustable value. Each time the condenser charges up by current supplied through the resistance to the spark over voltage of the .005" gap an oscillatory discharge takes place between the condenser and the primary of the coil and a secondary spark results. The voltage loading of the ignition coil can be regulated by the length of the secondary gap. The secondary gap shall be set to the maximum which will avoid secondary discharge flashing over the edges of the secondary insulating layers and the coil shall be run under these conditions for 5 hours. (8) Now check the final normal working current of the coil at 12 volts as previously observed in (4), and also the value of this current at one or two lower and higher speeds of the contact breaker, thus obtaining the consumption speed curve. (9) Observation shall be made of the coil performance | ||