摘要 |
A breakerless magneto ignition system for an internal combustion engine, having an inherent speed limiting feature is disclosed. The ignition system includes an ignition coil with primary and secondary windings, a drive winding and a trigger winding. A first solid state switch is placed in circuit with the primary winding for controlling current flow through the primary winding, the drive winding controlling the solid state switch to render it conductive to allow current flow through the primary winding, and the trigger winding and an associated switching circuit subsequently shunting the input to the first solid state switch to render it nonconductive, to block current flow through the primary coil and induce an ignition spark voltage in the secondary winding. The primary winding, secondary winding and drive winding are mounted on the same magnetic frame adjacent a magnet-containing flywheel, and the trigger coil is mounted on the lower edge of the secondary winding in close proximity to the flywheel. The primary winding current generates a field that interacts with the trigger winding to produce a premature pulse which increases in magnitude to prematurely activate the first solid state switch at a high engine RPM, at a point in the engine cycle at which there is insufficient current flow in the primary coil to produce an effective ignition spark voltage.
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