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).
Comparison and complete specification of test and measurements for experimental non-trembler ignition coils.
| Identifier | ExFiles\Box 69\1\ scan0278 | |
| Date | 23th December 1929 | |
| X 8710 X.3445. COMPARISON OF R.R. EXPERIMENTAL NON-TREMBLER IGNITION COILS X.8710 X.4501. Complete Specification of Test and measurements of Ignition Coils not intended for running on chassis. (1) Check metallic 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 with open secondary circuit under standard conditions for 15 minutes with a closed circuit supply voltage of 17.5 (average). Note. The term "standard conditions" referred to here and elsewhere implies the use in series with the primary of the coil of (a) A standard R.R. ballast resistance. (b) An R.R. contact breaker carefully adjusted to a make ratio of .55, shunted by an R.R. standard paper condenser (i.e. capacity at 80°C. between .275 and .325) and run at a speed of 700 r.p.m. (4) Immediately after (3) note the final normal working average primary current of the coil with a closed circuit supply voltage of 12.0 (average) still running otherwise as described in (3). Also note the final primary current when the secondary winding is short circuited. (5) Now connect H.T. of coil to distributor (assumed already connected to suitable 5 mm. spark gaps), and run the coil for 5 hours under standard conditions at the voltage of 17.5. Measure the secondary resistance after the run and | ||