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 comparing experimental coils.
| Identifier | ExFiles\Box 69\1\ scan0127 | |
| Date | 24th July 1928 | |
| X8710 24.7.28. 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 make and break running at 700 r.p.m. with a make ratio of .55 for 5 minutes at a supply voltage of 17.5 and for 10 mins. at 12 volts. (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. | ||