Burner ignition system
First Claim
1. An ignition system for a burner comprising:
- a low voltage electrical energy storage device;
circuit means for supplying low voltage, periodic current from said energy storage device;
a step-up transformer for converting said low voltage periodic current to a higher voltage output, the transformer having a significant leakage reactance due to leakage flux which makes up a substantial portion of the total flux through the transformer;
a capacitor charged by the higher voltage output from the step-up transformer; and
an output circuit for applying the capacitor voltage to an electrical igniter.
12 Assignments
0 Petitions
Accused Products
Abstract
An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.
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Citations
14 Claims
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1. An ignition system for a burner comprising:
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a low voltage electrical energy storage device; circuit means for supplying low voltage, periodic current from said energy storage device; a step-up transformer for converting said low voltage periodic current to a higher voltage output, the transformer having a significant leakage reactance due to leakage flux which makes up a substantial portion of the total flux through the transformer; a capacitor charged by the higher voltage output from the step-up transformer; and an output circuit for applying the capacitor voltage to an electrical igniter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An ignition system for a burner comprising:
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a pilot nozzle; a low voltage electrical energy storage device; circuit means for supplying low voltage, periodic current from said energy storage device; a step-up transformer for converting said low voltage periodic current to a higher voltage output; an output circuit for applying the high voltage output to an electrical igniter adjacent to the pilot nozzle; a thermostatically controlled valve; a main gas valve; circuit means for sensing a pilot flame and controlling the main gas valve; a safety valve in series with the main gas valve and pilot nozzle, the safety valve being normally closed but being opened by pressure differentials established by the thermostatically controlled valve, the safety valve including means for venting the gas which holds the valve open through a time delay orifice until a flame is sensed such that the safety valve is closed after a predetermined delay if no flame is sensed. - View Dependent Claims (13, 14)
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Specification