Abstract: A method and apparatus for controlling the operation of a burner apparatus are provided via the flame intensity of combustion reaction mixtures of oxidant and fuel gas.

Abstract: A method and a system for igniting a gas burner of a gas stove is disclosed, which includes a spark generating circuit to produce sparks for igniting gas burners and a plurality of electrodes which are connected with the spark generating circuit for the ignition of the gas burners. A flame sensor circuit is operated in a first period for producing sparks, through of the electrodes, and in a second period and once the gas burner has been ignited, for sensing the presence of flame on each gas burner. A power source is connected for limiting the voltage to the flame sensor circuit.

Abstract: A method for substantially maintaining an average heating temperature over a period of time without the aid of a temperature sensor. The method provides an apparatus which has an ignition device that is adapted to ignite a fuel. The apparatus may be a cooking appliance or practically any other device that is adapted to heat something. The fuel may be natural gas, propane gas, or practically any other fuel that may be ignited to provide heat. Conveyance means are provided for receiving the fuel from a source of the fuel and conveying the fuel to the ignition device. A valve is interposed on the conveyance means between the ignition device and the source of fuel. In order to substantially maintain the average heating temperature over the period of time, the valve is opened and closed in a predetermined pattern such that at least a portion of the fuel conveyed to the ignition device is ignited.

Abstract: In an electronic ignition system for igniting a plurality of gas burners by means of a plurality of electrodes, each one being mounted adjacent with each burner for producing sparks for the ignition of each burner. A spark generating circuit connected with the electrodes in order to produce the sparks for igniting each burner. And a power source connected to the spark generating circuit. A flame sensor circuit is connected to the spark generating circuit and at least one electrode, which in a first period and once the spark generating circuit has been activated for igniting each electrode, the flame sensor circuit is operated to detect the absence of flame on the burner by means of said electrode, and once that the burner has been ignited, the electrode and flame sensor circuit are operated for sensing the presence of flame on the burner.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a voltage phase regulator circuit for applying rectified half-wave AC line voltage, full-wave rectified AC, or either half-wave or full-wave rectified AC line voltage to the ignitor to supply power thereto, and AC line voltage to a blower motor, an AC-to-DC converter, a DC voltage preregulator, and a DC voltage regulator for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at consistent ignition temperature for a predetermined ignition trial time period and a second time constant circuit for driving second and third motor drive circuits.

Abstract: A gas appliance is provided for producing an open flame. The gas appliance includes an elongated gas tube, a gas inlet, a nozzle, a flame sensor, a gas shut-off valve, and a protective member. The gas tube has a proximal end and a distal end. The gas inlet is located near the proximal end, for connection to a source of combustible gas. The nozzle is located at the distal end, for expelling the combustible gas to produce the open flame. The flame sensor detects the open flame and communicates its absence or presence to the gas shut-off valve. The gas shut-off valve has a valve inlet, a valve outlet, a control input, and the over-ride mechanism. The valve inlet is connected to the gas inlet. The valve outlet is connected to the proximal end of the elongated gas tube.

Abstract: Apparatus for limiting the temperature of a cooking location of a type having an electrically conductive burner housing forming a heating chamber, includes a temperature sensor including an outer tube and an inner rod received within the tube, a switch base carrying at least one contact which is actuated by the temperature sensor, an electrode at least partially positioned in the heating chamber and secured to at least one element selected from the group consisting of temperature sensor and switch base, and a current measuring device having a first terminal connected to the electrode and a second terminal connected to the burner housing.

Abstract: An apparatus for drying a moving substrate containing a multiplicity of infrared emitters and a detection emitter and a device for supplying a mixture of air and gas to these emitters. The detection emitter contains an emitter body with a diffuser for distributing a fuel-oxygen containing gas mixture, a primary radiator having a combustion surface integrally connected to the emitter body, a first detection electrode, and a second detection electrode; each of these detection electrodes sends a signal to a control means when it senses the presence of flame-induced ionization. If the control means receives a signal from one but not both of these detection electrodes, it will continue supplying the air/gas mixture to the emitters. However, only when the control means ceases receiving a signal from both of the detection electrodes will it ceases allowing the supply of the air/gas mixture to the emitters.

Abstract: Systems and methods are disclosed that optimize the combustion process in various reactors, furnaces, and internal combustion engines. Video cameras are used to evaluate the combustion flame grade. Depending on the desired form, standard or special video devices, or beam scanning devices, are used to image the combustion flame and by-products. The video device generates and outputs image signals during various phases of, and at various locations in, the combustion process. Other forms of sensors monitor and generate data signals defining selected parameters of the combustion process, such as air flow, fuel flow, turbulence, exhaust and inlet valve openings, etc. In a preferred form, a neural networks initially processes the image data and characterizes the combustion flame. A fuzzy logic controller and associated fuzzy logic rule base analyzes the image data from the neural network, along with other sensor information.

Abstract: A gas heater is provided with a combustion status sensor that provides heater performance data to a controller that controls the heater according to the sensor data and stored calibration parameters optimized for the particular heater.

Abstract: An apparatus and process for controlling the operation of a gas burner, by monitoring and controlling the stoichiometry of the air and fuel gas during the burning process.

Abstract: A flame ionization detector having a pair of spaced electrodes to which a DC voltage is applied and a flame produced between the electrodes by burning a gas whose composition is to be determined, thereby ions are produced which form an ion current between the electrodes which is representative of the gas composition to be measured. The flame detector is formed by a base plate having a first channel for inlet of the gas whose composition to be measured, a second channel for inlet of a combustion gas, a third channel connected to the first and second channels for conveying a mixture of the gases to an outlet communicating with a nozzle outlet in a ceramic plate on the base plate which faces an opening in a metal plate spaced at a predetermined distance from the ceramic plate such that the flame burns in the opening in the metal plate. An electrically conductive metal layer is disposed on the ceramic plate around the nozzle outlet therein.

Abstract: A direct spark ignition control system is provided for controlling for a gas fireplace burner. A solenoid is operatively controlled for supplying gas to the gas fireplace burner. A high voltage spark ignition circuit is operatively controlled for generating ignition sparks near the gas fireplace burner. A flame sensing circuit coupled to the gas fireplace burner provides a feedback signal to activate and deactivate the high voltage spark ignition circuit. A timing and control circuit provides a control signal to energize the solenoid and provides a control signal to deactivate the high voltage spark ignition circuit and a control signal to deenergize the solenoid after a set time period with the burner flame feedback signal activated.

Abstract: Roofing kettle apparatus for heating asphalt includes a wheeled chassis mounting a vat and a heating system for heating the vat. The heating system includes a solenoid operated valve for controlling the flow of fuel gas from a fuel gas source to each of a pair of burner nozzles and a igniter assembly having an outlet adjacent the outlet of a first combustion chamber. An igniter generates a spark to ignite gas discharging from the igniter assembly outlet. A flame sensor adjacent to the first combustion chamber outlet end senses the burning of fuel gas. The igniter assembly has a second outlet adjacent the second combustion chamber outlet end. The ignition of fuel gas discharging from the igniter assembly ignites the gas discharging through the combustion chamber outlets. The burners extend into the combustion chambers.

Abstract: A process for controlling a gas blower burner in which an ionization electrode sends an electrical variable derived from the combustion temperature or the lambda value to a control circuit, which compares this variable with a selected electrical set point and adjusts the gas-to-air ratio (lambda value) to a corresponding lambda set point. To compensate the effect of a condition-dependent change in the proportionality between the lambda value and the electrical measured variable derived from it on the control in such a way that the desired lambda set point will be maintained, a calibration cycle is run from time to time. The lambda value is reduced from a value of >1 during this cycle. The maximum obtained at lambda=1 is stored. The electrical set point is adjusted with this maximum.

Abstract: An atmospheric burner is associated with a flame presence sensor and an electrical-discharge ignition device. It is fed via a flow rate control device. Both the ignition device and the flow rate control device are controlled by a microcontroller. A user interface enables the user to select the desired power by sending to the microcontroller a request for altering the flow rate and hence for altering the minimum power deliverable by the burner.

Abstract: In a cross flow type burner apparatus, a burner is provided to which a gaseous fuel and air are supplied by a blower. An air reduction member is provided to reduce an amount of air supplied to specified flame holes of the burner wherein the reduced amount of air is less than the amount of air supplied to the other flame holes. A temperature sensor is provided to detect the burning condition of flames built up on the specified flame holes. A safety member is activated depending on an output generated from the temperature sensor.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a voltage phase regulator circuit for applying rectified half-wave AC line voltage, full-wave rectified AC, or either half-wave or full-wave rectified AC line voltage to the ignitor to supply power thereto, and AC line voltage to a blower motor, an AC-to-DC converter, a DC voltage preregulator, and a DC voltage regulator for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at consistent ignition temperature for a predetermined ignition trial time period and a second time constant circuit for driving second and third motor drive circuits.

Abstract: In a process for operating a gas blower burner, a control circuit detects an ionization signal Ui derived from an ionization electrode, and it adjusts the gas-to-air ratio to a lambda set point >1, to which a set point Uis of the ionization signal corresponds. To guarantee low-emission combustion in different operating states, a range of control of the ionization signal Ui is set, whose upper limit value Uio is smaller than the maximum of the ionization signal Ui, and whose lower limit value Uiu is above the value that guarantees low-emission operation. A switch-off signal is generated for the burner if the ionization signal Ui leaves the permissible range of control RB for longer than a preset period of time.

Abstract: A system for automatically admitting and regulating the flow-rate of an alkaline substance admitted to the combustion chamber (10) of a refuse incineration plant for the hot destruction of the acids contained in the combustion fumes, comprising sensors (22, 23, 24, 25, 51, 124, 140) for detecting the concentration of the acids in the fumes in the combustion chamber (10) and working conditions of the plant such as temperature, flow-rate and humidity of the fumes, and processing means (26, 27) connected to the sensors for identifying, in dependence on the concentration of acids and of the working conditions, a flow-rate of an alkaline substance to be admitted to the combustion chamber in order to achieve a destruction yield which reduces the concentration of acids in the fumes discharged from the plant to a predetermined value, and for operating flow-rate regulation members (40) for admitting to the combustion chamber the flow-rate of an alkaline substance thus identified.

Abstract: The cooking grill has a moisture-insensitive flame detector capable of accurately determining the presence or absence of flame in the presence of moisture disposed adjacent to the burner. It also provides a more reliable ignition device and will relight the grill if the flame is blown out. The cooking grill also has an automatic shut-off to protect against the user forgetting to turn off the gas. It provides a lock-out system which prevents unauthorized use by individuals, such as children. Finally, the temperature in a grill or other cooking device can be controlled by cycling the burner on and off through microprocessor commands.

Abstract: A gas combustion apparatus comprises a burner, a thermal electric power generation element that uses the burner's combustion to produce a thermoelectromotive force, a voltage boosting circuit that raises the voltage of the thermoelectromotive force by the oscillation of an oscillation unit and a storage battery that is charged by the voltage-increased thermoelectromotive force. The oscillation unit consists of free running multivibrators and oscillates in dependence on the resistance of a positive temperature coefficient thermistor. If the positive temperature coefficient thermistor reaches a prescribed temperature or shorts out and fails, its resistance value changes and the oscillator unit stops its oscillation, whereby in the voltage boosting circuit the voltage rise stops, and electromagnetic safety valve closes.

Abstract: A detection system includes flame sources at least two of which are independently controllable; photodetectors each having an independent view of the flame sources and being capable of producing a respective current signal in response to flames produced by the flame sources; and a device for analyzing the current signals to determine state values of a plurality of state variables and transform the state values into at least one parameter value. A number of the flame sources is at least as high as a number of the state variables, and a number of the photodetectors is at least as high as the number of the state variables. In one embodiment, the flame sources include gas burners in a gas combustion chamber, the photodetectors include silicon carbide photodiodes, and the parameter value is representative of fuel rate, temperature, acoustic dynamics, nitrogen oxide concentration, or carbon monoxide concentration.

Abstract: Gas control apparatus to regulate the flow of gas to a plurality of burners is disclosed. The apparatus permits a main gas solenoid valve to be actuated for a pre-determined period of time allowing the burners to be ignited. If the burners are not ignited within the pre-determined period of time, the main gas solenoid valve is deactuated. Even though a main gas solenoid valve is utilized, each burner can be separately ignited by means of a start signal applied thereto. After ignition, the main gas solenoid valve will remain actuated only if a flame is present at the ignited burner and a start signal is applied to the remaining burners.

Abstract: Method and apparatus are disclosed for checking the responsiveness of a circuit which senses the presence of a flame produced by a burner within a furnace. A programmed processor associated with the circuit measures the time the circuit takes to indicate the presence of a flame. A warning is generated when the measured time exceeds a predetermined allowable time. The allowable time is determined by taking into account the decreased responsiveness of an electrode that indicates the presence of the burner flame.

Abstract: A combusting apparatus of the present invention can easily recharge an incorporated storage battery that has been exhausted to or below a required minimum level. A burner (18) in the combusting apparatus is further provided with a thermoelectricity generating element (4), which receives the heat of combustion and generates a thermoelectric e.m.f. When a multi-contact switch (16) is activated to set the arrangement of plural capacitors (15) in parallel, the capacitors (15) having the parallel configuration are charged with a thermoelectric e.m.f. generated by the thermoelectricity generating element (4). When an operation of a switching button (20) activates the multi-contact switch (16) to change the arrangement of the capacitors (15) from the parallel configuration to the series configuration, the sum of the voltages of the capacitors (15) is applied to an oscillation circuit (9) included in a booster circuit (8) as well as a storage battery (12).

Abstract: An electronic control system for gaseous fuel burners, particularly suitable for ovens and employs a single push-to-turn user control knob for selecting BAKE, BROIL or SELF-CLEAN modes of operation and for setting the oven temperature desired in the BAKE mode, the control knob turns a potentiometer shaft which provides a signal indicative of the shaft position to a microprocessor which controls relays for selectively opening and closing electrically operated BAKE and BROIL burner valves.

Abstract: A combustion of the present invention has a burner, a combustion fan supplying air to the burner, revolution rate detection means for detecting a revolution rate of the fan, and an air-flow rate sensor for detecting an air-flow rate of the air. The combustion device further has a temperature sensor for detecting a temperature at the combustion device and diagnosis means for performing a self-diagnosis to determine a ventilation condition based on a relationship between the revolution rate and the air-flow rate. The diagnostic means correct the detected revolution rate or the air-flow rate based on the temperature of the combustion device in the process of performing the self-diagnosis. The diagnosis means perform the self-diagnosis after a predetermined time has passed until there is no temperature variance in the combustion device since a combustion halts.

Abstract: A circuit arrangement for flame detection for a transistor coil ignition system of a burner is disclosed. The transistor coil ignition system features a trigger stage which triggers a power transistor that is located in the power circuit of the primary winding of an ignition coil in order to charge the primary winding of the ignition coil with a charging current from a power supply. A circuit arrangement includes a switch having an ignition position and a flame detection position which in the flame detection position restricts the charging current flowing via the primary winding of the ignition coil to an intensity that lies below the charging current intensity needed to generate an ignition spark in the ignition position, so that ignition spark-over cannot take place without a flame.

Abstract: A combustion apparatus has a built-in storage battery and has circuitry which restores a sufficient amount of stored electrical energy in the storage battery when the amount of electrical energy stored in the storage battery is lowered below a required level. A thermoelectric generator element is heated by combustion heat produced by a burner to generate a thermal electromotive force. A manual operation of a slide button causes an associated multi-contact switch to repetitively turn ON and OFF, such that a coil in a booster circuit boosts a voltage generated by the thermoelectric generator element. The boosted voltage is applied to an oscillator circuit in the booster circuit, so that the booster circuit is driven to boost the voltage from the thermoelectric generator element as well as to start powering the oscillator circuit and a storage battery. Consequently, a sufficient amount of stored electrical energy is restored in the storage battery.

Abstract: Gas control apparatus to regulate the flow of gas to a plurality of burners is disclosed. The apparatus permits a main gas solenoid valve to be actuated for a pre-determined period of time allowing the burners to be ignited. If the burners are not ignited within the pre-determined period of time, the main gas solenoid valve is deactuated. Even though a main gas solenoid valve is utilized, each burner can be separately ignited by means of a start signal applied thereto. After ignition, the main gas solenoid valve will remain actuated only if a flame is present at the ignited burner and a start signal is applied to the remaining burners.

Abstract: A fuel control system, parts therefor and methods of making and operating the same are provided, the fuel control system comprising an ignition unit for igniting fuel issuing from a burner, and a flame detecting unit for detecting flame at the burner, the flame detecting unit comprising a sensing device for receiving an electrical signal caused by flame rectification at the burner, and an output device for cycling the signal to the sensing device in an on and off manner in each cycle of operation of the output device, the control system having a modulating unit for modulating the on time and the off time of the output device in each cycle of operation thereof.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a circuit for applying AC line voltage to the ignitor and to a blower motor, an AC-to-DC converter for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at an ignition temperature for a predetermined ignition trial period of time, a second time constant circuit for starting the blower motor and providing fuel to the combustion chamber for a predetermined time concurrent with the ignition trial period, and a third time constant circuit that either maintains the fan blower in its energized state if a flame of sufficient magnitude and frequency is detected and for de-energizing the blower motor if the flame is not detected in less than one second after the ignitor is de-energized.

Abstract: A standalone modular flame sensor containing a multi-function power supply having outputs for both a flame rod and an ultraviolet transducer. The module also contains interfaces for the ultraviolet transducer and for the flame rod transducer. The interfaces are brought together at a summing junction arranged so that the module will work with either a flame rod, an ultraviolet transducer, or both such transducers. Output circuitry provides not only a flame-on/flame-off indication (both visible via an LED and a switch contact closure), but also provides a continuously variable signal indicating the quality of the sensed flame. The module can be used standalone with either transducer type or incorporated in a more complex control system.

Abstract: An apparatus and method to qualify the condition of a flame body is disclosed, where such apparatus comprises a power source, an amplifier and sensor means, where said sensor means includes two or more probes disposed in spaced apart relation so as to conduct a current and said amplifier is designed to selectively amplify the signal generated between said probes so as to isolate a selected frequency consistent with ionization of a given fuel/air mixture.

Abstract: A cooking hob comprising at least one gas burner 17, 18, 19 disposed beneath a glass top 25, said burner including a heat resistant rod 46 extending across at least part of the burner 17, 18, 19 and a thermocouple element 47 connected to the rod 46 for sensing the temperature of the glass 25 (FIG. 1).

Abstract: There is disclosed a modification in the control circuitry of a gas furnace having a primary or main limit whereby the primary circuit subsumes the functions of a the secondary or manual reset limit circuit. The control circuit incorporates a microprocessor capable of sensing conditions in the furnace, enabling and disabling the various furnace components.

Abstract: A control system controls a combustion burner. The system has an ignition electrode to create a flame in a burner, and a first temperature sensor to sense the temperature of the flame. A control terminates the operation of the ignition electrode when a predetermined temperature is sensed by the temperature sensor.

Abstract: A multi-stage, fail-safe fuel control circuit monitors a flame which emits photons and is supplied with fuel through a valve to a burner. The fuel control circuit includes a flame scanner adjacent the valve for generating a count signal including pulses provided at a rate proportional to the energy of the flame adjacent the burner. A timer provides at least one timing signal which periodically shifts between a first and second state. A capacitive pulse-height discriminator is coupled to the flame scanner and to the timer and measures the rate of the pulses in the count signal during the first state of the timing signal and generates a discriminator signal if the pulses exceed a desired rate during the first state. A capacitor discharge oscillator is coupled to the frequency discriminator and the timer charges a capacitor during the first state and provides an oscillating signal powered by the capacitor at a first frequency if the count discriminator signal is generated during the first state.

Abstract: Apparatus and method for sensing the operating condition of a burner temperature as the indicating variable. When the operating status is stable, the flue temperature should be nearly identical to that when the system was known to be in proper condition. During a time when the system is known to be in proper operating condition, the flue temperature is recorded during stable operation for a number of different firing rates. When identical or similar firing rates occur at a later time and operation is stable, the operating flue temperature is compared with the current flue temperature, and if substantially different, an operation status signal is set to a state indicating this change in operating condition.

Abstract: In a pilot light igniter for a burner, an inner tube for receiving fuel gas is concentrically positioned within an outer tube for receiving air in the annular space between the inner tube and the outer tube. Apertures are formed in the inner tube to impart angular momentum to the fuel gas as it flows from the inner tube into the annular space so that the mixture of air and gas swirls as it flows to the open distal end of the outer tube. A spark disk is provided on the end of the inner tube and a flame rod extends axially from the spark disk. The air and fuel mixture is ignited by a spark produced by high voltage applied between the spark disk and the outer tube. A low voltage source applied between the flame rod and the outer tube causing current pulses provides an indication of the presence of a flame.

Abstract: A safety apparatus for use with a gas burner having a thermoelectrically activated on-off safety valve for controlling gas flow to the burner, a governor for maintaining constant gas pressure to the burner, a gas channel interconnecting safety valve and governor, and a thermocouple for generating a thermoelectromotive force in the presence of a flame to electrically maintain the safety valve in an open position, is disclosed. The safety apparatus includes a gas pressure operator for sensing a predetermined excessive pressure within the gas channel and which initiates a shut-off of the gas supply to the burner upon sensing the high pressure gas in the channel. A connecting device is electrically connected to a solenoid in the safety valve for controlling the on/off position of the safety valve and is electrically connected to the thermocouple.

Abstract: A process and apparatus for monitoring and ensuring safe operation of unvented kerosene heaters in indoor spaces detects the hazard of incomplete combustion and the concomitant reduced O.sub.2 and increased CO.sub.2 levels in the indoor air. CO.sub.2 level in the indoor air is monitored quickly and accurately, - regardless of the burner's flame height. This is achieved by sensing O.sub.2 level in the burner exhaust which is used as a measure for monitoring the CO.sub.2 level in the indoor air and as a control signal. During burner operation outside a predetermined flame height range, the O.sub.2 detection is used both for restoring a normal heating condition and for monitoring operation at minimum flame height and to generate a warning signal and a delayed automatic shut-down of the burner.

Abstract: Gas control apparatus to regulate the flow of gas to a plurality of burners is disclosed. The apparatus permits a main gas solenoid valve to be actuated for a pre-determined period of time allowing the burners to be ignited. If the burners are not ignited within the pre-determined period of time, the main gas solenoid valve is deactuated. Even though a main gas solenoid valve is utilized, each burner can be separately ignited by means of a start signal applied thereto. After ignition, the main gas solenoid valve will remain actuated only if a flame is present at the ignited burner and a start signal is applied to the remaining burners.

Abstract: There are arranged a mixing room (4) for mixing fuel with air, flame ports (5) disposed downstream of the mixing room, an ignition plug and a flame rod disposed near the flame ports, and a catalyst layer (8) disposed downstream of the flame ports and bored with a plurality of communicating holes (8a). The operation includes steps of activating the igniting means (6) for forming a flame at the flame ports (5), extinguishing the flame after a predetermined time length by once stopping the fuel supply, and starting a catalytic burning reaction on the surface of the catalyst layer (8) by supplying fuel again without activating the igniting means (6).

Abstract: A primary gas furnace control including a thermostatically controlled intermittent ignition system, the control being effective to monitor and control main gas valve action through use of flame rectification. The control features a slight delay on main valve dropout with flame failure and an extension of the ignition source into the main burner cycle to prevent nuisance recycling. If desired, the control may also include timed pilot valve, thermostat resettable, lockout as well as prepurge capability for use in applications requiring a furnace combustion chamber purge prior to an ignition cycle.

Abstract: A burner control system conditions opening of the fuel control valve on proper operation of a hot surface igniter for igniting the fuel. Current flow through and voltage across the hot surface igniter is constantly monitored, and if either is not proper, the valve closes. A pair of diodes provides half wave DC current of different polarity respectively for the hot surface igniter and the valve actuator.

Abstract: A gas valve control system including a microprocessor, a first relay, a second relay, flame sensor and a timer. The timer is connected to the switch which is connected in the power supply path of the second relay. The second relay is connected to the valve. Activation of the first relay causes activation of the second relay causing the valve to open. Also, activation of the first relay causes the timer to operate. The flame sensors then must sense flame or else the microprocessor will deactivate the first relay. If the microprocessor fails to deactivate the first relay, the timer causes the switch to open and break the power supply path to the second relay. This in turn causes the valve to close.

Abstract: An acoustically operated burner control system for optimally controlling a flow of air and fuel into a flame producing combustion burner throughout a range of firing rates is disclosed. The system includes separate valve assemblies for modulating the flow of air and fuel into a burner, a microphone for generating an electrical signal indicative of the intensity of all sounds generated by the combustion flame having a frequency in excess of about 10 Khz, and a controller including a programmable microprocessor electrically connected to both the air and fuel valve assemblies and the microphone. The system further includes a wave guide for remotely acoustically coupling the microphone to the combustion flame in order to isolate the microphone from both heat and corrosive combustion products. Prior to the operation of the system, empirically-derived sound intensities associated with optimum stoichiometric combustion and minimum pollution are entered into the memory of the microprocessor.

Abstract: In a heating appliance employing a radiant burner, a method and apparatus for setting the ratio of gaseous fuel to air supplied to the burner to a desired value. With the gaseous fuel flow rate held constant, the air flow rate is controlled to maintain the fuel-to-air ratio at the desired value. The invention uses a sensor that measures the intensity of radiation emitted by the burner. A control device compares the measured intensity to a reference intensity and regulates the air flow rate such that the measured intensity is equal to the reference intensity. The burner emits radiation equal to the reference radiation intensity when it is burning a combustible gas supply containing the desired fuel-to-air ratio, so that by regulating the air flow rate to cause the burner to emit the reference radiant intensity, the fuel-to-air ratio will be at the desired value.