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).
Procedure for testing and comparing experimental coils.
| Identifier | ExFiles\Box 69\1\ scan0194 | |
| Date | 23th April 1929 | |
| X8710 23.4.29. COMPARISON OF EXPERIMENTAL COILS. X.8710. (1) First ascertain that the coil is in O.K. condition as regards continuity of windings. (2) Make suitable measurements of the resistances and inductances of the primary and secondary windings at ordinary atmospheric temperature, which temperature should be noted. (3) Ascertain that the coil will stand up to open circuit under standard conditions for 5 minutes at a supply voltage of 17.5 and for 10 mins. at 12 volts. Note. The term 'standard conditions' referred to here and elsewhere means running the coil with a standard ballast resistance in series, a contact breaker make ratio of .55 and at a contact breaker speed and distributor speed of 700 r.p.m. (4) Immediately after the O.C. run note the normal working current of the coil at 12 volts running as described in (3), and also the primary current when the secondary winding is short circuited. (5) Allow the coil to take current with the contact breaker stationary and on contact, for one hour, using the 12 volt supply. Immediately after which the secondary resistance shall be measured and the temperature of the coil calculated from the increase in resistance as compared with that at the ambient temperature, which temperature should be noted. The final primary current shall also be noted. Contd. | ||