Abstract: A breakerless ignition system includes a resonant circuit whose oscillation is controlled by the relative position between a detector coil 2a embodied therein and a magnetically permeable rotor 1 driven by the engine, and a threshold detector 3 responsive to the oscillation signal envelope for controlling the supply of energy to an ignition coil 6 via a power switching transistor 5. To prevent false triggering of the detector due to spurious signals induced in the coil by the spark ignition firings, a monostable multivibrator 8 actuated by the trailing edge of the detector output holds the transistor deenergized for a predetermined period of time after it has been turned off. The multivibrator output may resistively ground the resonant circuit, or it may disable the transistor via an inverter 11 and AND gate 12.

Abstract: An ignition apparatus for an internal combustion engine which includes a signal rotor on a rotary shaft for being rotated in synchronism with a coil wound about a core, a metal heat sink, and a frame connected to the heat sink so as to form a casing. The frame has a recess opening to its interior and grooves extending into the recess. An integrated circuit is disposed on the heat sink. The integrated circuit includes a capacitor electrically connected to the core coil to form a resonance circuit, an oscillation energy supply circuit for supplying oscillation energy to the resonance circuit, an oscillation detector circuit for producing an output signal in response to the detection of the oscillation in the resonance circuit, an amplifier for amplifying the output signal, and a switch for interrupting the amplified signal. An ignition coil responds to interruption of the amplified signal by the switch for generating a high voltage.

Abstract: 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.

Abstract: A breakerless ignition system includes a resonant circuit whose oscillation is controlled by the relative position between a detector coil 2a embodied therein and a magnetically permeable rotor 1 driven by the engine, and a threshold detector 3 responsive to the oscillation signal envelope for controlling the supply of energy to an ignition coil 6 via a power switching transistor 5. To prevent false triggering of the detector due to spurious signals induced in the coil by the spark ignition firings, a monostable multivibrator 8 actuated by the trailing edge of the detector output holds the transistor deenergized for a predetermined period of time after it has been turned off. The multivibrator output may resistively ground the resonant circuit, or it may disable the transistor via an inverter 11 and AND gate 12.