IGNITION DEVICE AND ION CURRENT DETECTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an ignition device reducing noise included in ion current.SOLUTION: The ignition device 10 includes a discharge electrode 24 electrically connected to a secondary coil 13 and keeping a secondary gap 29 with a stem 34, and a diode element 25 connected between the secondary coil 13 and the stem 34 and connected in parallel with the second gap 29 so as to make ion current flow from the secondary coil 13 side to the stem 34 side. Electricity is discharged at the secondary gap 29 by applying plug discharge voltage generated at the secondary coil 13 side on the discharge electrode 24, and electricity is discharged at a first gap 36 by applying discharge voltage based on the discharge on the stem 34.