Investigation into the performance of U.S.A. Bosch battery ignition condensers, noting capacity drop and leakage when heated.
| Identifier | ExFiles\Box 34\1\ Scan306 | |
| Date | 5th August 1921 | |
| x2572 To CY. from Hs. {Lord Ernest Hives - Chair} Hs {Lord Ernest Hives - Chair} 2/LG5.8.21. X.2512. U.S.A. BOSCH BATTERY IGNITION CONDENSER X.3916. We have been carrying out some investigations on Delco (Packard) Delco (Marmon) U.S.A. Bosch Condensers. I think you have EFC {E. Fowler Clarke - Electrical Engineer} 's standard tests for condensers. We found if we tested the paper condensers (Delco and Bosch) on this test that we could not break them down, but that the condensers got very hot and when they were in a hot state there was a considerable drop in the capacity of the condenser due to leakage. We have tried running an ignition set with the Bosch condenser all day working in the Bench, but there is no sign of the condenser getting hot. This proves, we think, that our specified tests for condensers may be wrong because it has not prevented us having condenser failures yet, it would condemn condensers such as the Delco. Although the condenser does not get hot from its normal working, the condenser on the Bosch set does get very hot from conducted heat; this is proved by the fact that the wax melts. We have made a test on a Bosch condenser measuring the capacity whilst the condenser was resting on a hot plate and we found a very considerable drop in capacity as the temperature was increased. We recommend that you take this matter up with the Bosch Co. and obtain from them the capacity of their condenser at different temperatures. We should also be interested to know why it is that the leakage takes place as soon as the condenser is warmed. We notice that the Delco people always fix their condenser on the outside so that they have a chance of being air-cooled. A mica condenser does not suffer in the same way when it is heated. We should also be very interested in knowing what is the test which American ignition manufacturers give condensers. The U.S.A. Bosch condenser is worse than the Delco for heating up when on our standard tests for condensers. Hs. {Lord Ernest Hives - Chair} | ||
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).