Abstract: An ignition apparatus includes a secondary winding spool having a secondary winding wound thereon. The secondary winding includes a low voltage end and a high voltage end that is configured for connection to a spark plug. The secondary winding at the high voltage end is configured in accordance with a predetermined radial thickness profile taken in the direction from the high voltage end towards the low voltage end. The profile is determined as a function of (1) a reflected voltage associated with the spark gap breakdown of the spark plug and (2) an induced voltage due to magnetic flux coupled through a central core. The profile is determined so as to reduce layer-to-layer voltage levels in the secondary winding near the high voltage end. The profile can be wound or can be molded in the secondary spool itself.

Abstract: An ignition system for use with a spark plug in an internal combustion engine comprising an ignition apparatus for producing a breakdown voltage on a first output thereof configured to breakdown a spark gap of the spark plug a power source having a second output configured for connection to the spark plug, said source being further configured to sustain power to the spark gap during discharge and an impedance having first and second terminals coupled between the first and second outputs, the impedance having an electrical characteristic configured to allow application of the breakdown voltage and suppress high voltage transient.

Abstract: An electrical connection between a high voltage terminal and a spark plug head. A case contains a high voltage terminal connected to a high voltage source. A connector portion extends from a bottom portion of the case, which in turn is secured to an insulator boot for attachment to the spark plug. The high voltage terminal has a nipple extending within the connector portion. A barrel shaped coil spring is snapped over the nipple and positively retained thereto. The head of the spark plug is inserted within the connector portion and engages the barrel shaped coil spring. The barrel shape of the coil spring offers a smaller height with an increased working length thereby providing a larger tolerance between the high voltage terminal and the spark plug head.