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 construction and features of an American Bosch Ignition Coil Type TC.30.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan087 | |
| Date | 5th November 1926 | |
| EFC. WB.{Mr Brazier/Mr Bell}109. 5.11.26. AMERICAN BOSCH IGNITION COIL TYPE TC.30 AS USED ON RR.CHASSIS IN U.S.A. The special feature of this coil, apparently is that the secondary is wound next to the core and the primary on the outside. The H.T. end of the secondary is connected to the core at one end of which is the H.T. terminal. This greatly simplifies the construction and assembly of the coil, obviating the necessity of an expensive insulated moulded case. The resistance of the primary is, however, increased for a given inductance owing to the greater length of wire. There is no ballast resistance with this coil, and the heating of the primary winding due to excessive current would probably be efficiently radiated, due to its close proximity to the cold metal case with its large radiating surface. The weight of the coil complete is 2 lbs. as compared with our standard which is 1.75 lbs. (For numerical details of coil see covering note EFC2/T8.11.26). It would be interesting and instructive, after this coil has been thoroughly tested, to open it up and examine the windings and methods of construction. EFC/H.E.West. | ||