Breakerless magneto ignition system

A breakerless magneto ignition system for an internal combustion engine wherein a flywheel containing a magnet assembly is rotated synchronously with the engine operation for the purpose of inducing a current in a primary coil and the coil is switched OFF at a particular time the engine cycle for the generation of an ignition spark on a secondary coil that is magnetically coupled to said primary coil, said breakerless magneto ignition system comprising:

• a primary winding;
• a second winding that is magnetically coupled to said primary winding;
• a solid state switch for controlling the primary winding current flow:
• first means for driving said switch into conduction in response to said rotating magnet assembly for turning the primary current ON at a first selected time;
• second means for driving said switch into nonconduction in response to said rotating magnet assembly for turning the primary current OFF at a second selected time during the engine cycle, said means driving the current OFF at a third selected time in response to the magnet assembly rotating at a predetermined rate;
• said means for driving said switch into nonconduction including a trigger coil, said primary winding and said secondary winding are wound on a magnetic frame, and said second means includes a trigger coil mounted adjacent to the lower edge of said secondary winding close to said primary winding and responsive in part to a magnetic field of said primary winding, in a distal relationship from said frame.

A magneto ignition system for an internal combustion engine wherein a rotor contains a magnet and adjacent pole shoes extending from the edge of the magnet to the edge of the rotor, the rotor is driven in synchronism with the engine operation to generate a current in a first winding, the current is stopped at a point in the engine cycle for the generation of an ignition spark on a second winding electromagnetically coupled to the first winding, the first and second windings are mounted on a stator having at least two legs extending to the edge of said flywheel to receive the field from said pole shoes, and a third coil is mounted on said stator for actuating a solid state switch in circuit with the primary to establish the current flow through the first winding, the improvement in said ignition system comprising:

• a trigger coil mounted adjacent to the lower edge of said second winding, close to said first winding and responsive in part to a magnetic field of said first winding, and responsive in part to said magnet of said rotor, and substantially magnetically isolated from the field in said stator product by the flywheel rotation, for producing a first signal in response to said magnetic field effective only when said engine is operated above a predetermined rate, and a second signal responsive to said magnet,
• a second solid state switch in circuit connection with the trigger coil and the first solid state switch and actuated by said second signal to render the first solid state switch nonconductive when there is first coil current through said switch, whereby a spark pulse is produced by the second coil,
• said first signal rendering said first solid state switch nonconductive when there is insufficient first coil current through said switch to produce said spark.

A breakerless magneto ignition system for an internal combustion engine wherein a flywheel containing a magnet assembly is rotated synchronously with the engine operation for the purpose of inducing a primary coil current and the current is switched OFF at a particular time in the engine cycle for the generation of an ignition spark on a secondary coil that is magnetically coupled to said primary coil, said breakerless magneto ignition system comprising:

• a primary winding;
• a secondary winding that is magnetically coupled to said primary winding;
• a solid state switch for controlling the primary winding current flow;
• means for driving said switch into conduction and nonconduction in response to said rotating magnet assembly for turning the primary current ON and OFF at first and second selected times during the engine cycle, said means driving the current OFF at a third selected time in response to the magnet assembly rotating at a predetermined rate;
• said means including a trigger coil adapted to produce first and second pulses in response to the flywheel movement;
• said first pulse rendering said solid state switch nonconductive when said engine is operated below said predetermined rate;
• said second pulse rendering said switch nonconductive at and above said predetermined rate and occurring at a time in the engine cycle at which there is insufficient primary winding current flow through said switch to generate an ignition spark;
• said pulses being in a substantially constant phase relationship with each other.