Low Voltage Power Supply for Spark Igniter and Flame Sense
First Claim
1. A power supply circuit for use with intermittent pilot and direct spark ignition systems for gas burners, comprising:
- a low voltage DC power source;
a resonant circuit coupled to the power source, the resonant circuit including as an inductive element thereof a primary coil of a transformer;
an electronic switching circuit coupled in series with the resonant circuit;
a control circuit operatively coupled to the switching circuit to control switching thereof, the control circuit utilizing a low duty cycle control signal to control switching of the switching circuit; and
wherein the transformer includes a first secondary coil coupled to a flame sense electrode and flame sense circuit; and
wherein the transformer includes a second secondary coil coupled through a voltage doubler circuit to a spark capacitor in parallel with a primary coil of a step-up transformer and trigger circuit, the secondary coil of the step-up transformer being coupled to a spark electrode.
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Accused Products
Abstract
A low voltage power supply circuit for intermittent pilot and/or direct spark ignition systems utilized in gas burning appliances is provided. The circuit utilizes a single transformer and a resonant circuit to supply power to both a flame sense circuit as well as the spark generation circuit. The resonant circuit allows the use of low power sources such as batteries or self-supplied voltage systems such as thermopiles or hydro generators. Recognizing that power draw from the low power source is high during a sparking event and recharging of a sparking capacitor, the flame sensing is suspended during the sparking event and for a short recharge time thereafter.
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Citations
21 Claims
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1. A power supply circuit for use with intermittent pilot and direct spark ignition systems for gas burners, comprising:
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a low voltage DC power source; a resonant circuit coupled to the power source, the resonant circuit including as an inductive element thereof a primary coil of a transformer; an electronic switching circuit coupled in series with the resonant circuit; a control circuit operatively coupled to the switching circuit to control switching thereof, the control circuit utilizing a low duty cycle control signal to control switching of the switching circuit; and wherein the transformer includes a first secondary coil coupled to a flame sense electrode and flame sense circuit; and wherein the transformer includes a second secondary coil coupled through a voltage doubler circuit to a spark capacitor in parallel with a primary coil of a step-up transformer and trigger circuit, the secondary coil of the step-up transformer being coupled to a spark electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A power supply circuit for use with intermittent pilot and direct spark ignition systems for gas burners powered from a low voltage DC power source, comprising:
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an input filter circuit adapted to receive low voltage DC; a transformer having coupled in parallel with a primary coil thereof a capacitor to form a resonant circuit; a switching circuit operatively coupled to the resonant circuit to induce resonance therein; wherein the transformer includes a first secondary coil configured to power a flame sense circuit utilizing flame rectification to detect the presence of flame; and wherein the transformer includes a second secondary coil coupled to a spark capacitor, the spark capacitor being coupled to a primary coil of a step-up transformer and trigger circuit, the secondary coil of the step-up transformer configured to drive a spark electrode of an intermittent pilot or direct spark ignition system. - View Dependent Claims (18, 19, 20)
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21. A power supply circuit for use with intermittent pilot and direct spark ignition systems for gas burners, comprising:
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a low voltage DC power source; a resonant circuit coupled to the power source, the resonant circuit including as an inductive element thereof a primary coil of a transformer; an electronic switching circuit coupled in series with the resonant circuit; a control circuit operatively coupled to the switching circuit to control switching thereof, the control circuit utilizing a low duty cycle control signal to control switching of the switching circuit; and wherein the transformer includes a secondary coil coupled to a flame sense electrode and flame sense circuit and through a voltage doubler circuit to a spark capacitor in parallel with a primary coil of a step-up transformer and trigger circuit, the secondary coil of the step-up transformer being coupled to a spark electrode.
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Specification