Abstract: A microprocessor-based burner control apparatus includes an input stage adapted for controllably generating an input signal which is repetitively transitional between a first logic state and a second logic state. A synchronously controlled output stage includes a capacitor, a rectified source of alternating voltage and a microprocessor-switched transistor for controllably charging the capacitor during a half cycle of the alternating voltage having a first polarity. The capacitor is discharged during half cycles of the alternating voltage having a second polarity and the charging and discharging activity thereby actuates a load device. A programmable microprocessor is coupled to the input and output stages and is adapted to receive a synchronizing signal whereby the charging and discharging activity occurs in a predetermined relationship to the synchronizing signal. A method for controlling the operation of a combustible fuel burner is also disclosed.

Abstract: An improved system including a circuit for igniting a pilot burner each time heat is called for by a thermostat. The main burner is ignited by the standing pilot upon detection of pilot ignition. Trial ignition over a limited period of time is provided. Main and pilot oscillators each having only two transistors are employed to actuate respective main and pilot valves. Each oscillator is of a new type requiring few electronic components.

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.

Abstract: Apparatus mounted adjacent a gas burner comprising a tube attached to a high voltage electrode to form a spark gap of high voltage gas ignition and flame proving system wherein raw gas is supplied through the tube to enrich the gas mixture to a lower air to gas ratio around the spark gap to enhance ignition.

Abstract: The disclosure is directed to an improved catalytic combustion arrangement for use, for example, in a gas stove or the like, which has a heat insulation diffusion layer is provided in a catalytic mat layer for the improvement of combustion rate around the catalytic mat, and, through employment of two sets of thermo-couples, a heating burner for the catalytic mat is adapted to burn only during starting of combustion, and to be automatically extinguished upon arrival at a steady combustion state for continuous combustion only by the catalytic mat, with a simultaneous indication of such combustion.

Abstract: A burner control apparatus for use with a furnace installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, one or more devices for control of ignition and relay fuel flow, and a modulator controlling air and fuel flow to a main burner for varying heat output. The burner control apparatus comprises a lockout relay for shutting down the furnace, a control device for actuating the ignition and fuel control devices, and a timing circuit that provides several successive and partially overlapping timing intervals of precise relation, including a purge interval, a pilot ignition interval, and a main fuel ignition interval. The present invention includes circuitry for providing a purge interval with the modulator at a high air flow setting. After the purge interval, pilot flame ignition is prevented until the modulator has been moved to a low fire position.

Abstract: The invention relates to a control circuit for a semi-conductor power element, comprising a circuit generating a signal synchronous with the variable current supply signal of the semi-conductor power element, and a logic circuit with high input impedance to receive directly, on the one hand, the said synchronous signal and, on the other hand, the low strength detection signal and which is such that the delay circuit is combined to the high input impedance logic circuit to prevent the production of control pulses on the electrode controlling the semi-conductor or power element, if one of the components of the control circuit should become faulty.The invention finds an application in burner control and safety devices.

Abstract: A flame rod inserted in a flame created by the secondary air supplied to a burner is used to generate a flame signal voltage. This flame signal voltage fluctuates with the amount of secondary air available and with the fuel supplied. These fluctuations are relied upon by an integrated control system that utilizes a microprocessor or microcomputer to safely control an induced draft-type of furnace.

Abstract: Upon a call for heat, gas flows to a pilot burner, a spark generating circuit is energized to ignite the pilot burner, and an oscillator is energized. When flame appears, the output signal of the oscillator is effective, through flame responsive means including capacitor means and solid-state switch means, to enable energizing of the primary winding of a coupling transformer at the frequency of the oscillator signal. When so energized, sufficient power transfer occurs between the primary and secondary windings of the coupling transformer to enable energizing of a relay winding, which energizing terminates energizing of the spark generating circuit and allows gas to flow to the main burner.

Abstract: A hot wire type of gas ignition system uses a negative temperature coefficient resistor-ignitor element that is deenergized after ignition has occurred. The ignition and safety monitoring of the circuit is accomplished by a second flame detector means, and the flame responsive circuit that has been disclosed in a flame rectification circuit.

Abstract: A valve rod of a gas heating device actuates not only a microswitch, but also a disc valve. A pilot burner and a main burner are separately controlled by individual solenoid operated valve which is serially connected. The disc valve is provided at the upstream of the pilot burner, and between two solenoid operated valves for safeguarding against the erroneous on-state of the microswitch. A sensor will, according to the presence of the pilot flame, instruct an electric control board to continue or discontinue the sparkling of an igniter, to open or close the solenoid valve for supplying gas to the main burner. Thus, the adversity of toxication caused by either the misfunction of microswitch or failure of valve actuation is able to be prevented.

Abstract: A burner control apparatus for use with a fuel installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, and one or more devices for control of ignition and/or fuel flow. The burner control apparatus comprises lockout apparatus for de-energizing the control apparatus, a control device for actuating the ignition and/or fuel control devices, and a timing circuit that provides four successive and partially overlapping timing intervals of precise relation, including a purge timing interval, a pilot ignition interval, and a main fuel ignition interval. The present invention further includes a burner control system which verifies the proper operation of certain sensors in a burner or furnace including particularly the air flow sensor.

Abstract: A fuel burner control system that is fail safe and which controls three fuel burner functions is provided for. The system utilizes two different digital clock means that are separated in time from one another to ensure separate gating of the fuel burner output functions. The system further uses a negative power supply with respect to the circuit ground for control purposes while energizing the output switch means with a positive potential thereby eliminating inadvertent operation in the event of circuit component failures.

Abstract: A fuel burner control system that has a fail safe mode of operation utilizes a flame sensing means that controls two separate signal processing circuits that have two different threshold levels of operation. Each of the signal processing circuits controls a separate switch means and these switch means are interrelated to ensure that a pilot valve and main valve are opened in sequence and that a pilot flame is properly burning before the main valve is opened. If the flame sensing means for the device senses any abnormality, the interrelationship of the output circuits prevents the main valve from opening.

Abstract: There is disclosed a control system for a gas burner appliance having an interrupted pilot burner operation. The system employs serially-connected first and second (main) electromagnetic operated valves. The first valve has a dual coil construction with a hold coil which can retain the pilot valve open and a pick coil which, acting in concert with the hold coil, can move the first valve to its open position. The control system utilizes one double pole, double throw relay in circuit with a lockout switch, the voltage source, the thermostat switch, and the cold switch contact of the flame switch. The igniter and pick coil are in circuit to the normally open contact of the relay thus being deenergized after a flame is detected at the pilot burner. The coil of the main gas valve is in circuit with the voltage source, the thermostat switch, the normally closed contact of the relay and the hot contact of the flame switch.

Abstract: When a call for heat is established, a flame relay is actuated for a predetermined time by means of a cycling timer. Upon this initial actuation, the flame relay inhibits a checking relay and initializes a trial-for-ignition (or simply "ignition") timer. After the cycling timer times out and the flame relay has been completely cycled, which establishes operativeness of the flame relay and flame sensing circuitry, the checking relay is enabled and actuated for the ignition period. The checking relay then actuates the pilot valve and a spark generator to start a pilot flame. If a flame is sensed, before the ignition timer times out, the flame relay actuates the main valve and establishes a holding current for the ignition timer so that the checking relay continues to be energized. If a flame is not sensed during the trial period, the ignition timer disables the checking relay, thereby de-energizing the pilot valve before the main valve is opened.

Abstract: An electrical control circuit is disclosed for controlling the operation of a pilotless gas system including an igniter and a gas supply valve, wherein the gas supply valve is initially opened a predetermined time after the igniter is activated, and the igniter is subsequently deactivated a predetermined time after the gas supply valve is opened. Specifically, a control first signal is produced to activate the appliance, which control first signal is delivered to a first logic circuit for activating the igniter, and to a first delay circuit which produces a second signal delayed from the first signal by a first predetermined time period. The second signal is delivered to a gas supply valve control circuit to open the supply valve, whereupon a detector produces a third signal in response to opening of the valve.

Abstract: A fuel supply and ignition control system for controlling the operation of pilot and main valves in an intermittent pilot type system. At the start of an ignition cycle, the pilot valve is operated to supply fuel to a pilot outlet for ignition by sparks generated by a spark generating circuit. When the pilot fuel is ignited, the pilot flame bridges the spark gap, and a flame sensing network, which is connected in circuit with the spark electrodes, generates a flame signal which is applied to an enabling circuit which responsively effects operation of the main valve. The enabling circuit includes a controllable switching device which in one embodiment, is maintained disabled in the absence of a flame signal and is enabled to cause a flame relay to operate and energize the main valve when a flame signal is provided.

Abstract: A condition control system in the form of a fuel burner control means is disclosed. A group of relays and their associated contacts are used to control the burner means. The status of the relays and their contacts are continuously checked by a control logic means by having the voltage on key relay output contacts fed into the control logic means through isolated signal transmission means. All of the relays are capable of being deenergized in the event of the need for safety shut down as determined by the control logic means.

Abstract: In a direct ignition gas burner control system wherein two valves are connected fluidically in series with the burner, a make-before-break thermostatically actuated switch is effective, when a set of "cold" contacts are made, to energize an electrical resistance igniter and to open a first of the two valves which opening enables a pressure actuated switch to close its contacts. When the igniter is above a temperature sufficient to ignite gas, the thermostatically actuated switch makes a set of "hot" contacts while its "cold" contacts are still made. In this intermediate contact position, a second of the two valves is opened, allowing gas to flow to the burner. Continued energizing of the igniter causes the thermostatically actuated switch to break its "cold" contacts, effecting de-energizing of the igniter. When the "cold" contacts are open, the pressure actuated switch provides a hold-in circuit for the valves.

Abstract: A control arrangement for a fuel ignition system having pilot and main valves in which the energization of the operate windings of the pilot and main valves, which are connected in series, is controlled by a silicon controlled rectifier. The SCR is enabled at the start of each ignition cycle by trigger pulses provided by a pulse generating circuit and when enabled, the SCR provides a shunt circuit path around the main valve winding permitting the pilot valve winding to be energized at its operating level effecting pilot valve operation and preventing the main valve from operating. When a pilot flame is provided, a capacitor of a flame sensing network is charged by flame rectified current, generating an inhibit signal for the pulse generating circuit which causes the SCR to be cut off, interrupting the shunt path to allow the main valve winding to be energized, effecting main valve operation.

Abstract: There is disclosed a control system for ignition and operation of a combustible gas burner for heating appliances. The control system is intended for use with fuel burners having interrupted or discontinuous pilot burner operation. The control system utilizes the characteristic of a thermomechanical flame sensor such as a diastat, thermocouple, or bi-metallic strip to control the cycling of the system in the event of extinguishing of the burner flame by momentary gas or electrical interruption or air drafts.

Abstract: Burner control apparatus includes a control device for actuating an ignition control means, and a timing circuit for providing an ignition timing interval which extends beyond flame detection for a timed interval. The timing circuit is actuated in response to a request for burner operation and the control device is energized in response to the actuated timing circuit. The control device is maintained energized if a signal from the flame sensor is received before the end of the ignition timing interval, and the control device is deenergized and lockout circuitry is energized in the absence of a signal from the flame sensor. Main fuel supply is delayed for the timed interval to provide pilot flame stabilization.

Abstract: A gas burner control system wherein a burner is directly ignited by an electrical resistance igniter includes a pressure actuated switch effective to permit automatic re-cycle of the system in the event of an electrical power interruption or a gas pressure failure, and to prevent such automatic re-cycle in the event of an ignition failure.

Abstract: A fuel ignition control system including a control arrangement for operating pilot and main valves of the system the pilot valve being operated to permit a pilot flame to be established, and the main valve being operated by a pilot flame sensing circuit which includes a controlled switching device enabled in response to the charging of a capacitor to a given value to effect the operation of the main valve, the charging of the capacitor being controlled by a further controlled switching device which supplies AC current to the capacitor in the absence of a pilot flame, preventing the capacitor from charging to the given value, and which supplies DC current to the capacitor when a pilot flame is established, permitting the capacitor to charge to the given value.

Abstract: Upon a call for heat, gas flows to a pilot burner and a storage capacitor begins to charge. When sufficiently charged, the storage capacitor effects the opening of a valve controlling flow of gas to a main burner disposed in igniting relationship with the pilot burner. A hold-in circuit maintains the main burner valve open once it is opened. Circuit means connected in circuit with the storage capacitor and spark generating circuit means is responsive to the presence of charging current to the storage capacitor for preventing sparking until the storage capacitor is sufficiently charged to effect the pull-in of the main burner valve upon discharge, and is subsequently responsive to the presence of a hold-in current for terminating sparking.

Abstract: When a call for heat is established, a flame relay is actuated for a predetermined time by means of a cycling timer. Upon this initial actuation, the flame relay inhibits a checking relay and initializes a trial-for-ignition (or simply "ignition") timer. After the cycling timer times out and the flame relay has been completely cycled, which established operativeness of the flame relay and flame sensing circuitry, the checking relay is enabled and actuated for the ignition period. The checking relay then actuates the pilot valve and a spark generator to start a pilot flame. If a flame is sensed, before the ignition timer times out, the flame relay actuates the main valve and establishes a holding current for the ignition timer so that the checking relay continues to be energized. If a flame is not sensed during the trial period, the ignition timer disables the checking relay, thereby de-energizing the pilot valve before the main valve is opened.

Abstract: A control arrangement for a pilot ignition type fuel ignition system includes a first switch device which effects energization of a pilot valve at the start of an operating cycle to supply fuel to a pilot outlet for ignition to provide a pilot flame. The first switch device is enabled by a control circuit which in turn is enabled over a path provided by a second switch device. The second switch device is enabled by a flame sensing circuit when a pilot flame is established and operates to effect energization of a main valve and to interrupt the enabling path for the control circuit, and a further flame sensing circuit maintains the first switch device, and thus the pilot valve, operated following operation of the second switch device.

Abstract: A system for controlling the pilot and main burner gas valves of a gas furnace or the like, including a pilot spark ignitor and a pilot flame sensor. A main burner valve control circuit for energizing the spark ignitor until a pilot flame is sensed and then energizing the main burner valve solenoid to provide gas to the main burner. A pilot solenoid valve control circuit for controlling application of power to the ignitor circuit and the pilot and main solenoids. A safety turn on control circuit which permits operation of the pilot valve and ignitor circuit for only a limited period of time to provide a fail safe operation of the ignition system.

Abstract: A fuel burner safe starting system which utilizes a pilot valve and a main valve is disclosed. A flame detection system operates in conjunction with a relay which properly ignites and operates the fuel burner system. In the event of a failure which improperly energizes the relay, the safe starting system prevents the fuel valves from opening.

Abstract: A fuel ignition control system including a control arrangement for operating pilot and main valves of the system the pilot valve being operated to permit a pilot flame to be established, and the main valve being operated by a pilot flame sensing circuit which includes a controlled switching device enabled in response to the charging of a capacitor to a given value to effect the operation of the main valve, the charging of the capacitor being controlled by a further controlled switching device which supplies AC current to the capacitor in the absence of a pilot flame, preventing the capacitor from charging to the given value, and which supplies DC current to the capacitor when a pilot flame is established, permitting the capacitor to charge to the given value.

Abstract: An ignition system is disclosed which controls an electrically operated fuel valve and a spark generating apparatus to cause the fuel to be ignited at a fuel burning apparatus. The system also includes a flame sensing means which inhibits operation of an oscillator a predetermined time interval after operation is initiated in the event a flame at the fuel burning apparatus is not detected by the flame sensing means. The output of the oscillator is applied to a voltage converter which, in turn, controls valve actuation and spark generation. The invention can be used to light either a main burner directly, or indirectly through a pilot burner.

Abstract: A fuel ignition system of the pilot ignition type including a control circuit for operating pilot and main valves of a redundant valve assembly, the control circuit having control relays which provide an interlock on start-up to prevent the energization of the valves under certain failure conditions, the control circuit including a flame sensing circuit which is operable to prevent start-up of the system when a flame is provided as the result of a leak condition for the pilot valve, and to terminate an ignition cycle causing complete shut off of fuel whenever a flame is provided as the result of a leak condition for the main valve.

Abstract: A system including a circuit for igniting or reigniting a pilot burner in a gas fired device each time heat is called for by a thermostat or otherwise. The main burner is ignited by the ignited pilot upon detection of pilot ignition. A sequencing interlock is provided for trial ignition over a limited period of time. An output of a main valve control acting through the sequencing interlock causes sustained actuation of a pilot valve control if the main valve control is actuated.

Abstract: A self-checking fuel ignition system of the pilot ignition type including a sampling flame sensor which effects periodic testing of the operability of a spark generating circuit to provide ignition sparks, and an energizing circuit which operates independently of the spark generating circuit but under the control of the flame sensor, to control the operation of fuel valves of the system and to effect the shut down of the system for loss of flame or ignition spark.

Abstract: A gas burner control system including a main burner and a pilot burner for igniting the main burner wherein the pilot burner is ignited only when the thermostat is calling for heat and gas is permitted to flow to the main burner only after the existence of a pilot burner flame adequate to ignite the main burner has been proven. A pressure actuated switch is effective, following an electrical power interruption or a failure of or an appreciable reduction in gas pressure, to prevent the resumption of gas flow to the main burner until a pilot burner flame adequate to ignite the main burner has been re-established.

Abstract: There is disclosed an electrical control system for the ignition of a burner such as a burner for household appliances having an interrupted pilot burner operation. The pilot burner is supplied with fuel by the first control valve which is activated open by the switch of the thermostat in response to heating demand. A combustion detection switch is provided at the pilot burner to activate a second control valve in the gas line to the main burner in response to the presence of a pilot burner flame. This flame switch has hot and cold contacts which are in control circuits to relays that operate switches in circuit to the ignition circuit and to a time operated deactivating switch. The opperations of these relays insure the inhibition of the ignition circuit once the second controlled valve is opened and the complete deactivation of the control system in the event that a pilot burner flame is not established within a predetermined time.

Abstract: A gas burner control system including a main burner and a pilot burner for igniting the main burner wherein the pilot burner is ignited only when the thermostat is calling for heat and wherein a normally closed bimetal operated safety switch is effective to provide a trial ignition period for igniting the pilot burner. An electrical resistance heater for effecting opening of the safety switch is in the gate cicuit of a solid-state switch and is energized in the absence of pilot burner flame. The solid-state switch, when conducting, is effective to complete an electrical circuit through the safety switch to open a first valve and initiate gas flow to the pilot burner. When pilot burner flame exists, the resistance heater is de-energized, the first valve is held open by means including a switch responsive to gas pressure downstream from the first valve, and a second valve, fluidically in the series with the first valve and controlling the flow of gas to the main burner, is opened.

Abstract: A pilot gas conservation system for flare stacks is provided in which the activation and control of the pilot gas burners is determined by the wind conditions so that if no flare gas is flowing the pilot burners are shut down and with moderate and minor wind conditions the supply of pilot gas is maintained at a lower level than that required for higher wind velocities. A flow responsive switch is provided to determine the flow of waste combustible gas to the stack so that, if required, the effect of the wind speed determines the pilot gas flow.

Abstract: A control arrangement for a fuel ignition system including redundant pilot and main valves, includes a thermal heat sensor mounted on a heat exchanger or in an exhaust stack of main burner apparatus and having a heating element which is energized in response to operation of thermostatically controlled contacts to close associated contacts to effect energization of the pilot valve permitting fuel to be supplied to a pilot outlet and the main valve which is operated when a pilot flame is established, the heating element being deenergized when the main valve is operated and the heat sensor being responsive to heat from the main burner to maintain the contacts closed maintaining the pilot valve energized. The heat sensor responds to a flame out condition to deenergize the pilot valve, thereby interrupting fuel flow to main valve.

Abstract: An ignition system for heating appliances which burn gas or vaporous fuels. A spark igniter is programmed to ignite a pilot burner which in turn ignites a main burner. A flame rod is used to confirm to the control circuitry that pilot ignition has taken place before the main gas valve is opened. An initially closed timing control circuit opens the pilot gas valve but times out if ignition of the pilot does not occur within a predetermined time. Other circuit interlocking features are provided for overall fail-safe operation.

Abstract: A system for controlling the pilot and main burner gas valves of a gas furnace or the like, including a pilot spark ignitor and a pilot flame sensor. A system with both pilot and main burners normally off, with the pilot burner being turned on when the thermostat switch closes and with the main burner being turned on when the pilot flame is established, with the main burner being turned off whenever the pilot flame goes out. An electronic circuit with the flame sensor as an input for switching the main burner valve solenoid on and off, with the electronic circuit having a fail safe configuration such that failure of any component between the flame sensor and the relay controlling the main valve solenoid will result in the solenoid being unenergized.

Abstract: A fail-safe, self-checking ignition and control system for a gas burning apparatus having a pilot burner which is initially ignited by electric ignition means upon a need for operation of the apparatus and which in turn ignites a main burner after a flame is established at the pilot burner, the gas flow to the pilot burner being through a first valve and the gas flow to the main burner being through a second valve receiving its gas supply from the first valve. Energization of the ignition means and the two valves is controlled by circuit means of the system including a time delay device, two relays, and solid state flame detecting means. Each time the system is initially energized upon a need for operation of the gas burning apparatus, it tests the critical components of the system and acts to prevent operation of the apparatus if the failure of any such critical component is detected.

Abstract: A fuel ignition system including a control arrangement which provides an interlock on start-up to prevent the energization of fuel valves of the system under certain failure conditions, and an igniter which is enabled when the system is activated to provide ignition sparks for igniting fuel supplied to a fuel outlet, the igniter being disabled when a flame sensing relay operates and a timing circuit of the igniter permitting the igniter to provide ignition sparks for a predetermined time duration following the operation of the flame sensing relay.

Abstract: This invention relates to an apparatus for automatic gas ignition control for igniting an auxiliary fire nozzle and main fire nozzle in a water heater, to precisely, safely and automatically ignite the gas. The apparatus for automatic gas ignition control according to the present invention provides an alarm to give early warning if the unit is not being fed a sufficient amount of gas. Further, this invention provides a gas flow controller to control the flow rate of gas dependent upon the change of water level or pressure requirements. Also this invention provides an electric circuit for igniting the auxiliary fire and the main fire. If any component in the electric circuits is damaged, the circuit will cease to operate or function and no gas will flow. This provides an absolute protection avoiding accidents.

Abstract: A system for controlling the pilot and main burner gas valves of a gas furnace or the like, including a pilot spark igniter and a pilot flame sensor. A relay having a first standby mode providing power to the spark igniter circuit when the thermostat switch is closed and the pilot valve solenoid is energized, and a second operating mode disconnecting power from the spark igniter circuit and providing power to the main valve solenoid when a flame is sensed at the pilot burner. A fast responding, stable and failsafe circuit for operating the relay utilizing a 24 volt supply, with a 48 volt supply provided only for the flame sensor.

Abstract: An oven burner control system having a manual rotary valve controlling gas flow to main and pilot burners and a solenoid operated valve controlling flow to the main burner, control circuit means embodying spark ignition means to ignite the pilot, means responsive to conduction through pilot flame to cut off spark ignition and permit operation of the solenoid valve, and variable resistance means responsive to oven temperature effecting cyclic operation of the solenoid valve. A control knob rotating with the manual valve varies the control point of said temperature variable resistance means and actuates a line switch to connect and disconnect the control circuit with a power source.