Ignition coil with controllable inductance and capacitance - has magnetic material round secondary to increase leakage reactance and isolated metal sheath to increase capacitance to earth

摘要

The ignition coil incorporates a magnetic and a metallic insert which effectively puts an inductance in series with, the spark discharge across a capacitor. The discharge wave shape and component are frequencies to give improved engine ignition. The primary coil (2) is wound in two series connected halves round the outer limbs of a three limb magnetic circuit (1) and the high voltage secondary coil (3) is wound round the centre limb of the magnetic circuit. A high magnetic permeability screen (5) is placed over the secondary coil to increase its leakage reactance, and an insulating cylinder (6) is placed over this screen. A thin metal screen (7) is placed over the insulating layer. It does not form a closed circuit and is connected to the outer metal case (10) of the oil filled (13) coil, to form the capacitance between the secondary and earth. A flexible capsule (15) absorbs expansion of the oil with temperature.