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).
Test procedure for the comparison of experimental coils.
| Identifier | ExFiles\Box 69\1\ scan0077 | |
| Date | 15th February 1928 | |
| X8710 15.2.28. 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 but otherwise normal running by operating it in series with a standard ballast resistance with a standard distributor running at 700 r.p.m. with a make ratio of .5, for 15 minutes, at the supply voltage of 12. (4) Note the normal working current of the coil 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, and using the same supply voltage as before, immediately after which the secondary resistance shall be measured and the temperature of the coil calculated from the increase in resistance. (6) With the make ratio of the distributor altered to .55 the coil shall be run for 5 hours at a voltage of 17.5 under similar standard conditions as before, and the secondary resistance again measured immediately after the run, and the temperature of the coil calculated as in (5) above. Cont.d | ||