An ignition system includes a signal generator unit 1 comprising a sensor core/coil, and an electronic circuit unit 2 including various components mounted on a substrate board. Both units are accommodated within a unitary casing comprising a frame 5 and a heat sink 10 on which the board is mounted. The casing has an open end or face in which the core is mounted in proximity to an engine driven rotor. The interconnecting leads between the coil and substrate board include terminal plates 6 and short straps 7 to avoid spurious high frequency radiations and induced signals.

The control generator of an ignition distributor for a transistor-coil ignition comprises an annular coil (55), a rotor (54) and a stator, which is a riveted unit comprising a stator plate (18), a permanent magnet (17) and a pole disc (56). The rotor and the pole disc are molded elements of sintered iron or of a mixture of sintered iron powder and carbonyl iron powder having a binder of thermosetting resin. The rotor and the pole disc have cooperating pole teeth (59,51), which are directed parallel to the axis (60) and whose cross section is triangular, with the triangular tips oriented toward one another. These "pointed teeth" produce a more steeply inclined signal course, as a result of which a decreased inherent shifting of the inductive transducer, and thereby more reliable starting of the engine, are attained.

To eliminate frictional effects by stationary elements (17, 37, 47) with respect to a sleeve (16, 36, 46) which rotates with a shaft (11) of a distributor, but is adjustable with respect to the instantaneous position about the shaft by a centrifugal spark advance mechanism (15), the nonrotatable elements (17, 37, 47) are secured from a support plate (22, 32, 49) which is positioned intermediate the sleeve and the distributor rotor, the support plate being journalled by bearings (23, 33, 44, 45) directly on the shaft. A load-dependent vacuum chamber can be linked directly to the support plate for additional load-dependent spark timing adjustment.

A method of assembling a distributor (10) includes integrally mounting a magnetizable ring (14) directly to a camshaft (20) and establishing magnetic poles on the ring (14) when the engine is in a known position. A sensor (54) has a known position with respect to the poles on ring (14) and is used to generate information about engine rotation.

To provide a signal representative of angular crankshaft position from an ignition distributor, independently of change of ignition timing, the ignition distributor includes a further or additional rotating transducer system (8, 9, 10, 11), for example a rotating disk (8) positively coupled to the shaft (3) of the distributor. The disk (8) carries markers (10) which are picked up by an optic, magnetic (Hall generator) or inductive pick-up (9). To provide a reference marker output, for example a reference, e.g. TDC position of a reference piston, the rotating disk (8) can carry an additional reference marker (10a) picked up by a reference pick-up (9a) which can be similar to the other pick-ups used in the construction. The specific crankshaft position signals are especially suitable and desirable if the engine is coupled to an engine knock sensing and knock prevention system (KS).