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).
Description of the general characteristics of a new type of magneto called the Magnetobloc.
| Identifier | ExFiles\Box 4\5\ 05-page218 | |
| Date | 12th October 1921 | |
| X.430. Typed October 12th, 1921. X.430. THE MAGNETOBLOC. GENERAL CHARACTERISTICS. The object of the inventors of these new magnetos may be summed up thus :- 1. To obtain by new methods an intensification of the magnetic field, inducing a higher voltage at the secondary terminals, to give stronger sparks at the slowest speeds, even with bad carburetion. 2. To simplify manufacture by the standardisation of the parts for the different types in order to reduce production costs and consequently the selling price. Magnetic Flux. The special form of the magnet permits the pole shoes and the screws which fasten them to the magnet to be deleted. It therefore avoids the eddy currents which are set up in all magnetos when magnetic metals are in contact with one another (cast iron, hardened steel, mild steel). This form thus concentrates the maximum number of lines of force through the armature. The coil, with the useful surface proportionately larger, is therefore adapted to take a greater number of turns, which results in a much higher voltage. The shape of the top of the magnet allows of its being fixed upon the magneto, without having recourse to any lateral intermediary, or fixing by screws, the magnet is simply encased for its whole height between two antimagnetic plates front and back, of which one is in a piece with the Contd. | ||