Self Power For Ignition Coil With Integrated Ion Sense Circuitry
AssigneeWoodward Governor Company
InventorJeffrey B. Barrett
Life of this patent
Estimating the term…
Abstract
A self power circuit for ion sense circuitry is provided. The self power circuit is configured to supply the voltages required to generate and measure an ion current flow in a combustion chamber of an engine. The power circuit stores power from the current flow in the ignition coil secondary circuit during at least a portion of a sparking period for use during the ion current measurement period between sparking events. Ion current generation voltage as well as positive and negative sensor circuit power supply voltages are generated in one embodiment.
Claims25
A self power circuit for generating a bias voltage to enable an ion sensor to generate an ion current flow in a combustion chamber of an engine after a spark has been generated by bi-directional current flow from an AC ignition coil, the self power circuit comprising a bias supply circuit having a series connected bias supply capacitor and diode coupled in series with the ignition coil and a spark plug, the diode oriented to allow current flow through the bias supply capacitor to increase a charge stored thereon during a half cycle of the bi-directional current flow from the ignition coil to the spark plug during the generation of the spark, the bias supply capacitor coupled to the ion sensor at a first node to supply the bias voltage thereto from the charge stored thereon to generate the ion current flow.
An ion current generation circuit, comprising:
- an ignition coil configured to generate a spark current for a spark duration;
- a spark plug coupled in series to the ignition coil for generating a spark across a spark gap in a combustion chamber of an engine to cause an ignition event therein;
- self power circuit coupled in series with the ignition coil and the spark plug for generating a bias voltage during the ignition event to enable an ion current flow across the spark gap in the combustion chamber of the engine immediately following the ignition event, the self power circuit comprising a bias supply circuit having a series connected bias supply capacitor and diode, the diode oriented to allow current flow through the bias supply capacitor to increase a charge stored thereon during a half cycle of the AC current flow from the ignition coil to the spark plug during the spark duration;
- and
- wherein the bias supply capacitor discharges across spark gap to cause the ion current flow immediately following the ignition event.
A sensor power circuit for generating a control voltage after a spark has been generated by bi-directional current flow from an AC ignition coil for an engine, comprising a first and a second power circuit capacitor coupled through anti-parallel diodes, respectively, oriented to allow current flow through the first and the second power circuit capacitors during opposite half cycles of the bi-directional current flow from the AC ignition coil during the generation of the spark to increase a first charge stored on the first power circuit capacitor and to increase a second charge stored on the second power circuit capacitor, the first charge and the second charge being opposite in polarity.
Dependencies are inferred from the claim text.