Patent ID: 7355300

Claim:
An exciter circuit for use with an igniter for creating a spark for igniting fuel in an engine; comprising: a charge pump circuit for selectively applying power to an input of a voltage conversion device having a first output, said device being configured to step-up a first voltage level applied to said input to a higher second voltage level at said voltage conversion device first output; a main energy store having positive and negative terminals, said positive terminal being connected in circuit to said first output for receiving energy from said charge pump circuit, said negative terminal being connected to the igniter via a ground loop circuit having a step-up pulse transformer therein; a semiconductor switch having an anode, a cathode and a gate for controlling the release of energy from said main energy store, said cathode being directly connected to ground and said anode being connected to said positive main energy store terminal; and, a trigger circuit connected to said charge pump circuit and to said gate and selectively applying a trigger signal to said gate for placing said switch into conduction thereby discharging said energy store directly to ground, said ground loop circuit producing negative current through said step-up pulse transformer to said negative terminal and thereby creating a high voltage negative pulse that is applied to the igniter for creating a spark.