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).
Request to prepare an experimental ignition coil with a tapped secondary winding for voltage measurement.
| Identifier | ExFiles\Box 69\1\ scan0300 | |
| Date | 16th January 1930 | |
| X8710 Sft{Mr Swift}/Mr.Brock from EFC. c. By.{R.W. Bailey - Chief Engineer} EFC3/AM16.1.30. X.8710. IGNITION COIL WITH TAPPED SECONDARY WINDING FOR VOLTAGE MEASURMENT. Will you please prepare for us an experimental coil to O/54733 with certain secondary layers looped out to enable us to get the necessary connections for measuring the maximum voltage available at each of these points. The first three loop outs should correspond to the first six layers, i.e. a loop out after every 2nd, 4th and 6th layer and these loop outs may be spaced 120° relatively to one another. For the next 12 layers it will be sufficient to loop out every 4th layer, and for the remainder of the winding every 8 layers. So that the total number of loop outs corresponding to a total of 54 layers will be 9 as described. There will be 12 final layers without a loop out. EFC. | ||