Importance

Loading Importance Indicators...

Abstract

A magneto ignition system having inherent means for providing operating biases for components thereof at temperature extremes is disclosed. The disclosed ignition system includes an ignition coil (10) having primary and secondary coil (12, 14) a solid state or semiconductor switch (24) being connected across the primary coil (12) for switching the current therein, and drive and trigger coils (20, 34). The semiconductor switch (24) is driven toward a nonconductive state, to cause an ignition impulse in the secondary coil, by semiconductor latching device (32) which shunts the signal from the drive coil (20) to ground (38). The semiconductor latching device (32) is activated by a trigger coil (34), having a separate magnetic flux path. In order to provide reliable switching at extremes of ambient temperature, means (22) responsive to the common magnetic field of the primary coil, the secondary coil, and the drive coil are provided to effectively provide operating bias to the latching device (32). In the illustrated embodiment, the means responsive to the magnetic field are paths on a printed circuit board (52, 52a) interconnecting the coils and components of the magneto ignition system. When the magnetic field begins to collapse in response to a trigger pulse, this collapsing magnetic field generates a voltage to insure that the latching device (32) reliably changes to a conductive state, and that the switch device (24) reliably changes to a fully nonconductive state, either by decreasing the effective impedance of the electrical path through the latching device (32) or by increasing the effective impedance of the electrical path to the semiconductor switch device (24).

Loading the Abstract Image...

First Claim