Fig. 17.—Remy Inductor.
Fig. 18.—Inductor Giving Six Waves.
In types of magnetos that have recently been produced, the winding is stationary and surrounds a moving core that is magnetized and demagnetized during its revolution between the poles of the field magnets. The Remy magneto is of this type, and Fig. 17 is a diagram of the revolving core, or inductor, with the coil surrounding it. As the inductor revolves, the magnetism flows from one pole of the field magnets into the wing of the inductor nearest to it, through the central cylindrical part, and by the second wing to the other pole, the central part of the inductor then being magnetized. The magnetism of this portion dies away when the wings are in such a position that they bridge across from one pole to the other, but reappears when the central cylindrical part again becomes the only path by which the magnetism may flow. The constant changes in the magnetic strength of the central part affect the coil, and currents are induced in it. These currents, which are of low voltage, are led to the primary winding of a secondary induction coil similar to that used in the Eisemann system, the secondary current flowing to the plugs through a distributer located on the magneto. In the Remy system, the interrupter does not short circuit the magneto winding, as is the case with the Eisemann, but the flow of current is from the magneto winding to the grounded side of the interrupter, to the insulated screw, to the primary winding of the coil, and back to the magneto. The interrupter is closed and the current flows in this circuit while the strength of the current is increasing, but when the current is at a maximum the interrupter breaks the circuit, the core of the coil loses its magnetism, and a secondary current is induced. The current reaches a maximum twice in each revolution.
In other magnetos, the form of the inductor is such that six or more waves of current are produced during each revolution. An inductor of this type is shown in Fig. 18. There are six arms radiating from the central cylindrical portion, three at each end, and equally spaced. The coil is usually made of flat copper ribbon instead of wire, and it surrounds the central cylindrical part between the two sets of arms. In the inductor shown, the magnetism of the central part will change strength six times to each revolution.
Magnetos of this type are used to replace batteries in jump spark systems using vibrator coils. They are driven by belt, or by friction against the fly wheel, and are given a speed at least three times that of the crank shaft. By this means the waves of current follow one another at such brief intervals that the flow is practically continuous, and it is therefore unnecessary to time the magneto to the engine. These magnetos have no interrupters, and the wiring consists of one wire leading to the switch on the coil box, the usual connections between the coil box and timer, and a wire from the second magneto terminal to ground.
MAGNETIC MAKE-AND-BREAK SYSTEM
Fig. 19.—Magnetic Igniter.