Method and apparatus to reduce ring out in an ignition coil to allow for ion sense processing
US7778002B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2007 |
| Grant date | Aug 17, 2010 |
| Priority date | — |
| Expiry date | Jan 8, 2029 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02P2017/125
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.