Denso Corporation

Tsutomu Oosuka

Masamichi Shibata

Atsuya Mizutani

Yasuomi Imanaka

Yuji Kajita

An ignition apparatus is provided with a Zener diode as a limiter device, which limits a primary voltage of an ignition coil to be less than a Zener voltage, and a switching circuit, which prohibits a limiter function of the Zener diode at a start of discharge and switches the limiter device to perform the limiter function for a predetermined time period following the start of discharge. A secondary voltage is limited to be more than a secondary limit value. Even when blowout arises in discharging, re-discharging is avoided from arising immediately after the blowout and exhaustion of a spark plug caused by repetition of discharging is avoided.

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Gamagori, Japan

Tsutomu Oosuka