Patent ID: 7475669

Claim:
An ignition control apparatus for an engine comprising: an electric power source; a first igniter plug in a combustion chamber, the first igniter plug being energized by the electric power source; a second igniter plug in a combustion chamber, the second igniter plug being energized by the electric power source; a voltage detector for detecting a voltage of the electric power source; and a controller configured to effect initial combustion by the first and second igniter plugs, to determine whether the voltage is lower than a prescribed threshold voltage, and to effect further combustion by using one of the igniter plugs when the voltage detected by the voltage detector is lower than the prescribed threshold voltage, the controller being further configured to detect a rate of reduction of the voltage, to determine whether the rate of reduction of the voltage is lower than a predetermined threshold rate, and to effect further combustion using one of the igniter plugs when the voltage is lower than the prescribed threshold voltage and the rate of reduction of the voltage is lower than the predetermined threshold rate.