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).
Instruction sheet detailing the electrical properties and test results of a coil's primary and secondary windings.
| Identifier | ExFiles\Box 54\4\ Scan063 | |
| Date | 29th June 1920 | |
| RR 238 (150 BKS.) (SH37 29-6-20.) MP 224388 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. (2) Customer's No. Primary winding. Resistance 16°C = .662 ohms Impedance = 2.75 ohms Inductance = .0084 henry. Secondary winding. Resistance 16°C = 2705 ohms Impedance = 9320 ohms Inductance = 28.0 henries. When run in conjunction with our standard distributor at 700 rpm (make ratio .5) the coil successfully underwent an open circuit test at 12v for 5 mins the running current being 1.38 amperes. Also the coil functioned perfectly at 8 volts no misfiring being observed on 6.5 mm gaps the running current at 8v being 1.05 amps. Signed H.E.W. This Sheet must be filed on completion of the work. | ||