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).
The setup and parameters for a temporary non-trembler ignition system on chassis 7 CA.
| Identifier | ExFiles\Box 34\1\ Scan027 | |
| Date | 10th December 1918 | |
| COPY To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Ry. c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EH. X-2512 EFC1/AT10.12.18. 1 X.3129 X.682.-RE TEMPORARY NON-TREMBLER IGNITION FOR 7 CA. We are rigging up on a chassis 7 CA a non-trembler ignition, making use of the usual R.R. chassis contact breaker and distributor. Normal Assuming the/speed of operation of the ignition to be 500 r.p.m. of the contact breaker, corresponding to 30 miles per hour of the car, we have worked to a magnetic field energy at break of our standard amount of .060 joule. We have found out experimentally the curve connecting the make ratio and the gap of the platinums of this particular contact breaker. We have then calculated the necessary inductances of coils corresponding to the different values of the make ratio, also the neces sary total resistance of the circuit including the ballast. It is possible, on the one hand, to use a coil of a low inductance and a circuit of a low resistance with a small make ratio or a big gap, and on the other hand to use a coil of high inductance and a circuit of larger resistance with a large make ratio and small gap. In each possible case, for the same energy of magnetic field at break, we consume the same average current from the battery. We tried on the bench four cases which are represented as No.1,2,3,4, on the accompanying sheet. No.1 is a (Contd). | ||