US 2008/0278884 A1 · METHOD AND APPARATUS TO REDUCE RING OUT IN AN IGNITION COIL TO ALLOW FOR ION SENSE PROCESSING

Abstract

An ignition apparatus includes a transformer having a central core, a primary winding disposed thereabout, a secondary winding disposed outwardly of the primary winding, and an outer core or shield disposed outwardly of the secondary winding. The central and outer cores and the primary and secondary windings define a magnetic circuit through which magnetic flux flows during various phases of operation. An end-of-spark natural ringing of the secondary voltage is suppressed and limited by a control winding disposed in relation in the magnetic circuit. The control winding has a pair of terminals across which is connected a diode. The diode is oriented so that during a spark event, it is reverse biased but after the spark event it becomes forward-biased when the secondary voltage is positive so as to selectively facilitate dissipation of any residual electrical charge. Ringing is further suppressed by a resistor connected across the primary winding, or selectively connected across the primary winding using a controlled switch.

Claims32

Dependent claims

An ignition apparatus comprising:

a central core having a longitudinal axis, said core comprising magnetically-permeable material;
primary and secondary windings outwardly of said core;
a shield outwardly of said primary and secondary windings, said shield comprising magnetically-permeable material wherein said core, said primary and secondary windings and said shield are included in a magnetic circuit, said secondary winding having a high-voltage end configured for connection to a spark plug on which a secondary voltage is produced;
and
a suppression mechanism operatively coupled to said magnetic circuit configured to suppress ringing in said secondary voltage after a spark event.

2 more elements

An ignition system comprising:

an ignition apparatus having an output configured for connection to a spark plug having a spark gap thereof proximate a combustion chamber of an internal combustion engine, said apparatus being responsive to an electronic spark timing signal to generate a spark voltage on said output so as to produce a spark across said spark gap for initiating combustion in said combustion chamber;
and
an ion sense detection system configured for connection to said spark plug to generate a bias voltage for measuring an ion current using said spark plug, said measured ion current corresponding to a level of combustion in said combustion chamber, wherein said ignition apparatus further includes:
a central core having a longitudinal axis, said core comprising magnetically-permeable material;
primary and secondary windings outwardly of said core;
a shield outwardly of said primary and secondary windings, said shield comprising magnetically-permeable material wherein said core, said primary and secondary windings and said shield are included in a magnetic circuit;
and
a suppression mechanism operatively coupled to said magnetic circuit configured to suppress ringing in said secondary voltage after a spark event.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus to reduce ring out in an ignition coil to allow for ion sense processing

Life of this patent

Method and apparatus to reduce ring out in an ignition coil to allow for ion sense processing

Life of this patent

Abstract

Claims32