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).
Various tests and experiments performed on a Goshawk ignition coil.
| Identifier | ExFiles\Box 45\4\ Scan108 | |
| Date | 1st December 1922 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFG. c. CJ. & PN.{Mr Northey} c. By.{R.W. Bailey - Chief Engineer} & EP.{G. Eric Platford - Chief Quality Engineer} c. Rg.{Mr Rowledge} & Da.{Bernard Day - Chassis Design} X4079A EFC5/T1.12.22. X4079 - GOSHAWK IGNITION COIL EXPERIMENTS Attached please find copy of my assistant's report on various tests in connection with Goshawk ignition. Test 1. An endeavour was made to obtain the temperature of a coil on the engine by rising resistance of its secondary winding. By this method, however, the temperatures were lower than were expected and it is almost certain that the temperature of the bakelite material of the cases was higher than this. It would appear better to put an independent resistance possibly inside the coil case cover for this purpose. Test 2. An endeavour to estimate the insulation resistance and with A.C. leakage effects at high temperature was also made as described, but this, contrary to expectations, showed no appreciable reading of the voltages used, though the D.C. ammeter would easily have indicated 1/10 m.a. and the A.C. 1/2 m.a. Test 3. It will be seen that our bench tests do not indicate any irregularity in the ignition due to slow speed running. Test 4. As will be seen from the figures, the deletion of the hedgehogging of the core ends of the coil appreciably reduces the inductance and increases the running current accordingly, without apparently increasing the performance, at any rate at moderate speeds. At the high speed end, no doubt with the lower inductance missing would not occur Contd. | ||