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).
Breakdown tests of a battery ignition distributor rotor.
| Identifier | ExFiles\Box 61b\2\ scan0104 | |
| Date | 12th April 1929 | |
| EFC. WD.{Mr Wood/Mr Whitehead}53. 12.4.29. BREAKDOWN TESTS OF BATTERY IGNITION DISTRIBUTOR ROTOR We have conducted tests at high voltages, obtained on our H.T. transformer, on five mushroom type rotors taken at random from production. The voltage was applied between the rotor finger and a cam fitted in its usual position on the inside taper hole. The first one tried broke down after half a minute sustained at 19100 volts R.M.S. As this test was considered too strenuous the voltage on the next one tested was raised to 15100 volts R.M.S. but this also broke down after two minutes. The third rotor was only subjected to 12100 volts R.M.S. which it withstood successfully for 10 mins. A fourth rotor also successfully withstood this voltage for 10 mins. but the fifth broke down at this voltage after 8 mins. The limiting voltage that these rotors will withstand therefore appears to be in the neighbourhood of 12000 volts R.M.S. We consider this to be insufficient and to cope with the possibility of flaws in manufacture the average breakdown figure should not be less than 15000 volts R.M.S. EFC/H.E.West. | ||