Adaptive spark ignition and flame sensing signal generation system

• US 8,066,508 B2
• Filed: 05/12/2005
• Issued: 11/29/2011
• Est. Priority Date: 05/12/2005
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Chian, Brent, Nordberg, Timothy J.
• Primary Examiner(s): Denion; Thomas
• Assistant Examiner(s): BERNSTEIN, DANIEL A
• Application Number:
  US10/908,467
• Publication Number:
  US 20060257805A1
• Time in Patent Office: 2,392 Days
• Field of Search: 431/18, 431/75, 431 77- 78, 431 24- 26, 361/247, 361/253, 361/256, 361/257, 361/230, 361/232
• US Class Current: 431/75
• CPC Class Codes: F23N 2227/36 Spark ignition, e.g. by means of a high voltage
• CPC Class Codes: F23N 2229/00 Flame sensors
• CPC Class Codes: F23N 5/123 using electronic means
• CPC Class Codes: F23N 5/203 using electronic means
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A signal generation system for flame ignition and sensing. The ignition signal generation is adaptive for improving flame ignition while eliminating excess energy usage. High voltage signals for flame sensing may also be provided. If more energy or speed is needed for ignition signal generation, then the flame sensing signal generation portion may be disabled to increase the amount of available energy. Adaptation for ignition signal generation may be guided by the results of flame sensing. The flame sensing voltage may be regulated based on the flame current strength. The flame current may be controlled within an optimum range to reduce rod contamination rate and yet provide reliable flame sensing when the rod contamination built up. The adaptation may be algorithmic-based with the facilitation of a microcontroller. The system may provide the high voltage signals from a low voltage power supply, such as that of 24 VAC.

Claims

1. A signal generation system comprising:

a high voltage source;

a control circuit connected to the high voltage source;

a spark rod connected to the high voltage source; and

a sensing rod connected to the control circuit;

wherein;

a voltage from the high voltage source to the spark rod is adjustable for appropriate sparking at the spark rod to light a flame;

the voltage to the spark rod is increased until there is successful ignition;

the voltage to the spark rod is decreased to reduce electromagnetic interference;

a rate of voltage applications to the spark rod for sparking is adjustable;

the sensing rod feeds back a signal to the control circuit to indicate whether there is a successful sparking at the spark rod; and

the sensing rod is configured to be disabled to more quickly provide a voltage to the spark rod.

2. A signal generation system comprising:

a voltage source;

an ignition circuit connected to the voltage source, wherein the ignition circuit is configured to provide a spark voltage to a spark rod to ignite a gas, wherein ignition of the gas produces a flame;

a flame sensor, the flame sensor sensing a presence of the flame; and

a controller connected to the voltage source, the ignition circuit, and the flame sensor, wherein the controller selectively activates the ignition circuit when the voltage of the voltage source reaches a variable spark voltage, wherein if a flame is not sensed after a period of time, the controller increases the variable spark voltage;

wherein the controller includes a timer and, if an amount of time on the timer when the flame is sensed does not exceed the period of time, the variable spark voltage is reduced, and if the amount of time on the timer when the flame is sensed does exceed the period of time, then the variable spark voltage is not reduced.

3. The system of claim 2, wherein the controller includes a memory for storing the variable spark voltage.

4. A signal generation system comprising:

a direct current voltage source, wherein the direct current source is configured to receive an alternating current signal having a first voltage and convert the alternating current signal into a direct current signal having a second voltage that is higher than the first voltage;

a control circuit connected to the direct current voltage source, wherein the control circuit is configured to store a direct current voltage and to selectively discharge the stored direct current voltage; and

a spark rod connected to the voltage source, wherein the stored direct current voltage is selectively discharged by the control circuit when the stored direct current voltage reaches a variable spark voltage to energize the spark rod; and

wherein;

the stored direct current voltage from the direct current voltage source to the spark rod is adjustable for appropriate sparking at the spark rod to light a flame;

the variable spark voltage is increased until there is successful ignition; and

the variable spark voltage is decreased to reduce electromagnetic interference.

5. The system of claim 4, wherein a rate of voltage applications to the spark rod for sparking is adjustable.

6. The system of claim 5, further comprising:

a sensing rod connected to the control circuit; and

wherein the sensing rod feeds back a signal to the control circuit to indicate whether there is a successful sparking at the spark rod.

7. The system of claim 4, wherein the stored direct current voltage applied to the spark rod is adjusted by loading or unloading an output of the direct current voltage source.

8. A flame sensing system comprising:

a voltage source;

a flame sensor connected to the voltage source;

a controller connected to the voltage source and the flame sensor, wherein the controller increases a voltage to the flame sensor in response to a weak flame current to counter contamination of the flame sensor;

an ignition circuit connected to the controller and the voltage source; and

an adaptation mechanism for adjusting spark energy, duration and/or rate of a spark to be provided by the ignition circuit, according to at least one parameter; and

wherein the controller is configured to disconnect the flame sensor from the voltage source to facilitate the adjusting spark energy, duration and/or rate of a spark.