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).
Comparison of the primary inductance and construction of Remy 6 and Remy 12 coils.
| Identifier | ExFiles\Box 52\3\ Scan274 | |
| Date | 12th November 1917 guessed | |
| -3- Contd. The inductance of the primary of Remy 6 is greater than that of Remy 12 in a greater ratio than the rate of quantities. (No. of primary turns)² x cross sectional area of iron for the two coils. This may be accounted for by the fact that the iron wires constituting the core of Remy 6 are bent out at right angles at the top so as to go some way towards completing the magnetic circuit, whereas in Remy 12 they are not. This would seem to be an advantage when there is relatively plenty of time for the primary current rise, because it improves the coefficient of mutual inductance of primary and secondary by reducing leakage. A slight % increase in this coefficient means a much larger % increase in the effect produced in the secondary, and therefore a smaller coil. The feature, however, by increasing the self inductance of the primary, necessitates a longer interval of make, if the primary current at break is to be the same. EFC. {E. Fowler Clarke - Electrical Engineer} | ||