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).
Issues with production battery ignition condensers exceeding their capacity limits and proposing a new type of paraffin waxed paper condenser.
| Identifier | ExFiles\Box 165\5\ img022 | |
| Date | 24th September 1930 | |
| X7700 Ev.{Ivan Evernden - coachwork} from EFC. EFCL/AD24.9.30. X.7700. X.7701. BATTERY IGNITION CONDENSERS. Recently we have tested the capacities of seven production condensers and found everyone of these to be over the top limit of capacity given in our production specification of test. The percentage difference above the average figure given ranges from 17 in the lowest capacity condenser to 46% in the highest. It is very undesirable to have the condenser capacity over the limit given as this may lead to misfiring by reducing the available H.T. voltage at the sparking plugs. It is understood that a certain allowance has been made because of the tendency for the capacities to be reduced in service. We consider we should have been informed of any departure and also informed of any observation of decrease in capacity in service, as such decrease has not been definitely our experience. X6037. Further to the above we have recently arrived, from a number of tests, at the conclusion that the condition of the tungsten contact breaker points after considerable running remains a good deal better with a lower value condenser than with our present standard value, therefore, for this reason, we are all the more disappointed with the fact that condensers have been sent out with capacities above the limit. We may even shortly be recommending a lower range of capacity limits for the condenser. In regard to the use of paraffin waxed paper condensers, we ran a number of experimental condensers so made up and these behaved satisfactorily. This type of condenser shows a greater constancy of capacity with temperature variation than those made up with the varnished paper and they are also, we understand, cheaper to manufacture. We suggest that a batch of say 50 might be sent out on production, it being extremely unlikely that any condenser failure will arise with such action. Will you please say if you are in agreement. X and time EFC. | ||