Abstract: A water heater control system comprising an energy storage system electrically connected to a pilot valve operator and electrically isolated from a main valve operator. The energy storage system may be electrically connected to an ignition circuit. A thermoelectric device is in thermal communication with the pilot flame and electrically connected to a main valve operator. The water heater system may include a microcontroller configured to establish electrical communications between the device and the energy storage system, the pilot valve operator, and the main valve operator. The microcontroller may be configured to recognize a call for main burner operation, and may also be configured to check an available voltage of the energy storage system against a setpoint. The microcontroller may establish pilot flame operation with or without main burner operation, depending on whether a call for heat or recharging of the energy storage system is required.

Abstract: A heating device includes a combustion chamber, a housing in fluid communication with the combustion chamber, a burner disposed in the housing, a blower assembly connected to the housing for directing air into the interior of the housing, a valve assembly connected to the housing for controlling a flow of fuel into the burner, an optical color sensor for sensing a color profile of a surface of the burner, and a control unit configured to control the valve assembly in dependence upon the color profile of the surface of the burner.

Abstract: A system or apparatus that in one implementation includes an electromagnetic valve having an actuator rod with a first coil and a second coil positioned at different longitudinal locations on the actuator rod and being situated electrically parallel to one another in an electrical circuit. The electromagnetic valve is constructed to induce a first voltage in the second coil when the electromagnetic valve is in the open position and to induce in the second coil a second voltage lower than the first voltage when the electromagnetic valve is in the closed position. A switch changeable between a first position and a second position is located in the electrical circuit. When the switch is in the first position the electrical circuit is configured to allow current from a power source to be delivered to the second coil. When the switch is in the second position the electrical circuit is configured to not allow current from a power source to be delivered to the second coil.

Abstract: A control system for the ignition of a gas burner that include an electromagnetic valve having a first coil and a second coil, the activation of the first and second coils controlling the flow of gas through the electromagnetic valve. An ignition element which is designed to be heated until it reaches the gas combustion temperature of the gas delivered to the burner is disposed electrically in series with the first coil, the ignition element and first coil forming a branch. The control system also includes an auxiliary electromagnetic valve with a coil, the activation of the coil controlling the flow of gas through the auxiliary electromagnetic valve. The flow of gas towards the burner is allowed when both the electromagnetic valve and the auxiliary electromagnetic valve are open.

Abstract: A locally powered intermittent pilot combustion controller may include an igniter, a thermal electric and/or photoelectric device that produces an electrical signal having power when exposed to a flame, and a local power source for providing power when the thermal electric and/or photoelectric device is not exposed to a flame. In some cases, the intermittent pilot combustion controller may include a memory for storing information about an ignition sequence for igniting a pilot flame, and a controller coupled to the memory. The controller may be configured to initiate the ignition sequence of the pilot flame using information stored in the memory, determine whether the ignition was successful by monitoring the electrical signal produced by the thermal electric and/or photoelectric device, and adjust the information stored in the memory based on whether the ignition sequence completed successfully.

Abstract: Apparatus for sensing the presence of a flame issuing from the flow of fuel through an elongate oven burner comprises an electrical current sensor immersed in a flame having carbon atoms which support such current. The fuel is ignited by a spark igniter. Should no flame exist after a predetermined time interval, or if the flame is extinguished, the supply of fuel to such burner is terminated and the spark igniter is disabled.

Abstract: A control system for a fuel-fired appliance and methods of operating are disclosed. In an illustrative embodiment, when an electrical characteristic of an optical detector, such as a resistance, does not change by at least a predetermined amount during an ignition trial, and/or when a level of EMI or electrical noise detected by an antenna in a burner assembly of the fuel-fired appliance does not increase during the ignition trial, the control system may determine that the ignition assembly is not sparking properly. In some instances, the control system may also be programmed to activate an indicator that would indicate to a user or technician a potential problem with the ignition assembly (e.g. not sparking properly to ignite fuel).

Abstract: Disclosed herein is a method of controlling a gas type clothes dryer. The method control the dryer to continuously detect condition of a flame sensor even after ignition of the dryer, thereby preventing a drying operation from being performed when a flame has been extinguished due to insufficient gas supply caused by failure of a gas valve.

Abstract: Apparatus for sensing the presence of a flame issuing from the flow of fuel through an elongate oven burner comprises an electrical current sensor immersed in a flame having carbon atoms which support such current. The fuel is ignited by a spark igniter. Should no flame exist after a predetermined time interval, or if the flame is extinguished, the supply of fuel to such burner is terminated and the spark igniter is disabled.

Abstract: A system for generating a high DC voltage for a spark to ignite a flame in a combustion device, and a high AC voltage for a flame rod to sense a flame in the device, from a low voltage for combustion device control. The system may be an inexpensive mechanism.

Abstract: An ignition control device including a controller section and a remote control section for a gas appliance (e.g., a gas stove or a gas water heater) is disclosed. A signal communication between the controller mounted on a burner of the gas appliance and the remote control section held by the hand is done by transmitting and receiving RF waves therebetween. The invention can correctly ignite the gas appliance and audibly inform a user of any ignition failures or abnormal conditions.

Abstract: An apparatus is provided for controlling a fuel fired heating appliance, the apparatus comprising a first processor for controlling the ignition operation of the furnace and a second processor for controlling the operation of a variable speed blower motor, wherein the first processor sends communication signals to the second processor requesting a desired speed of the blower motor to provide air flow for combustion. The second processor responsively sends a signal to the first processor indicating the receipt of the requested speed for the blower motor. The apparatus further comprises at least one pressure switch, where the first processor senses an opening of the pressure switch and responds by successively sending incrementally higher speed request signals to the second processor until the first processor detects the closing of the at least one pressure switch.

Abstract: The system (1) for controlling the combustion (7) of a cooking oven burner (2), comprises in combination a thermostat valve (3) with a rotary hand knob (4) and a non-electric temperature sensor (6) for modulating the burner flame (7), and an electromagnetic safety valve kept open for ignition, and a electronic module (10) supplying in a first moment a DC power supply to the safety valve (8), which is then maintained open by a thermocouple (9) heated by the main flame (7). A common electrode (18) is provided both for electronic flame detection and ignition. During the burner pre-ignition step, the absence of flame detection signal (If) permits the gas flow (G) to be cut off after a short timed interval, irrespective of the thermocouple response. In the event of the AC power supply being cut off, the thermocouple (9) and the thermostat valve (3) keep the burner modulated independently.

Abstract: An apparatus for controlling gas valves in a gas drier is provided. The apparatus includes an igniter, a closed flame detection switch and a sustaining relay. The igniter, which starts a flame, connects to a first terminal which provides a power signal with respect to a neutral terminal. The closed flame detection switch is connected between the igniter and the neutral terminal thereby receiving the power signal via the igniter. The closed flame detection switch also detects a flame by opening. The sustaining relay provides an alternative path of conduction with respect to the closed flame detection switch.

Abstract: A gas furnace control arrangement includes a control unit control unit and an operating unit adapted to control the control unit, the control unit having a valve seat holding a set of solenoid valves, the solenoid valves including a main valve for fuel gas input control, a mother flame valve adapted to control a gas passage from the valve seat to a mother flame nozzle, a high flow rate valve and a medium flow rate valve and a low flow rate valve adapted to control a respective gas passage from the valve seat to a main flame nozzle, the operating unit including a power switch adapted to switch on/off an electronic igniter and to close/open the main valve and the mother flame valve, a strong flame switch adapted to close/open the high flow rate valve, a medium flame switch adapted to close/open the medium flow rate valve, and a weak flame switch linked to the strong flame and the medium flame switch and adapted to close/open the low flow rate valve.

Abstract: An oil burner control system is disclosed in which recycling between a loss of combustion to re-establishment of combustion is limited by counting the number of times recycling occurs and causing a the system to stop recycling and go to lockout after the count reaches a predetermined value.

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 gas oven comprises at least a first burner element disposed within an oven cavity of the gas oven. A first control valve is disposed within a gas line connected to the burner element and to a gas source. The control valve controls gas flow to the burner element. A first temperature sensor is positioned so as to detect temperature about the burner element. A controller is electrically coupled to the temperature sensor and to the control valve wherein the controller ensures successful ignition of the burner element by monitoring the temperature signals generated from the temperature sensor to determine if the temperature signals increase a rate that is greater than a predetermined.

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 gas oven comprises at least a first burner element disposed within an oven cavity of the gas oven. A first control valve is disposed within a gas line connected to the burner element and to a gas source. The control valve controls gas flow to the burner element. A first temperature sensor is positioned so as to detect temperature about the burner element. A controller is electrically coupled to the temperature sensor and to the control valve wherein the controller ensures successful ignition of the burner element by monitoring the temperature signals generated from the temperature sensor to determine if the temperature signals increase a rate that is greater than a predetermined.

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: An ignition/reignition circuit (10) for a gas burner (12) having separate flame sensing and ignition electrodes. The flame sensing electrode (25,30) trips a switch (Q1) upon transition from sensor output signals indicative of the sensed presence of a flame to a sensed absence. The switch is coupled to a spark generator circuit which includes a spark electrode (16) for reigniting the burner in the event of flame failure.

Abstract: A gas burning power supply section 10 for igniting gas includes a secondary battery and a solar battery for charging the secondary battery, and the operating voltage from the power supply section 10 is supplied to a gas ignition circuit 30, a flame detection circuit 50 for detecting the flame after the gas is ignited, and a solenoid valve-controlling timer circuit 60 for controlling the gas supply. A day/night discrimination circuit 100 is provided in association with the power supply section 10, and the ignition circuit 30, the flame detection circuit 50 and the timer circuit 60 are individually set in operation in accordance with a day/night discrimination output during the nighttime. In the event the flame of burning gas goes out halfway, the timer circuit 60 operates to perform a trial including reigniting operation, and if the reigniting fails during a trial period, the gas supply is automatically shut off.

Abstract: An electrically operated line valve has its outlet connected to the inlet of the manifold for supplying the user actuated individual gas burner valves and a user actuated line power switch is closed before opening of any of the burner valves. A valve position detector signals an electronic controller which supplies power to the line switch only if a burner valve has been opened after closing of the line switch. A user actuatable manual override cable enables the line valve to be manually opened during periods of electrical power outage.

Abstract: A heat exchanger system, a fuel control system therefor and methods of making the same are provided, the fuel control system having an electrical circuit means that comprises an ignition trial portion, a flame sensing control portion and a timer portion that comprises a counter having a plurality of outputs and a timer that clocks the output of the counter on each discharge of the timer, the timer portion also comprising a capacitor, a trial time resistor and a wait time resistor that are selectively placed in series with the capacitor by the counter when clocked to certain outputs by the timer to determine an ignition trial time period and a wait time period, and a transistor operatively interconnected to the capacitor to discharge the capacitor when flame is sensed by the flame sense portion.

Abstract: An ignition/reignition device for a gas burner which eliminates the isolation transformer of the prior art which includes a capacitive discharge curcuit which is connected to a high voltage transformer so as to provide ignition pulses to ignite a gas burner and which has a flame current amplifier and flame rectification sensors connected to the capacitive discharge circuit so as to control it so that spark discharges will occur if the burner has been turned on and such sparks will continue until ignition and wherein upon disappearance of the flame the sparks will again occur to reignite the burner.

Abstract: A heat exchanger system, a fuel control system therefor and methods of making the same are provided, the fuel control system having an electrical circuit means that comprises an ignition trial portion, a flame sensing control portion and a timer portion that comprises a counter having a plurality of outputs and a timer that clocks the output of the counter on each discharge of the timer, the timer portion also comprising a capacitor, a trial time resistor and a wait time resistor that are selectively placed in series with the capacitor by the counter when clocked to certain outputs by the timer to determine an ignition trial time period and a wait time period.

Abstract: Time-delay circuit for automatic shutdown of furnace systems has an induced draft blower motor and a first circuit for providing energy to the blower motor from an energy source. A second circuit for energizing the primary control system of the furnace, includes a thermostat and an electronic switching means. When the thermostat is "closed", the second circuit is completed to energize the electronic switching element which starts the blower. An airflow switch is provided to sense the start of the blower and to thereby energize a primary control which provides gas to a burner of the furnace. A timer set to a predetermined time interval has an output and two input terminal connections, one connected to the output of the thermostat and another to the output of the primary control system. When the thermostat is "closed" and the burner is operating, the timer is disabled.

Abstract: A spark ignition system for a heater-type ignitor is disclosed. Current through the ignitor is transformed into a voltage which is utilized to operate a timing circuit which, in turn, causes operation of a valve permitting the flow of fuel to a burner. Operation of the valve can occur only after the expiration of a predetermined period of time during which the voltage applied to the ignitor and the current passing therethrough are continuously monitored thus ensuring that the ignitor has reached the ignition temperature of the fuel before the valve is permitted to open.

Abstract: Electronic control system for an oil burner has a primary direct current power source controlled by a thermostat and a secondary direct current power source independent of the thermostat. A first relay is in circuit with the oil burner motor to energize the same and a second relay is in series with the first and with an alternating voltage source for energizing the ignitor of the furnace. An electronic circuit controls the first relay switch and includes a pair of silicon controlled rectifiers (SCR's) connected in series for energizing the first relay. A second electronic circuit includes a pair of interconnected NPN transistors for controlling the operation of the second relay switch. The first NPN transistor is conductive when the second relay switch is energized and the second NPN transistor is connected to the first to turn "OFF" the same in response to flame being sensed in the furnace.

Abstract: A hot surface ignition system for a gas furnace and method of making the same are provided, the system comprising a high voltage circuit for being connected to a source of high voltage AC current, the high voltage circuit having a hot surface igniter therein and disposed in the path of gas issuing from a burner that is adapted to be fed gas from a source thereof through an electrically operated gas valve, a low voltage circuit for being connected to a source of low voltage AC current, the low voltage circuit having the gas valve therein and having a thermostatic switch therein controlling the energization of the low voltage circuit with the low voltage AC current, a first relay unit having contacts in the high voltage circuit and controlling the energization of the igniter with the high voltage AC current, and another relay unit having contacts in the low voltage circuit and controlling the energization of the gas valve, the other relay unit comprising two separate relays respectively having contacts that are

Abstract: A direct spark ignition system is provided with an improved spark generator powered directly from a low voltage dc source through an inverter controlled by a gated oscillator. The inverter is comprised of a step-up transformer having its primary winding connected between the power source and a common-emitter transistor having its base electrode connected to an output of the oscillator. A rectifier couples the secondary winding to a storage capacitor, and a spark discharge timing means controls periodic discharge of the storage capacitor into a spark electrode. A diode between the collector of the switching transistor and the storage capacitor is poled to couple back EMF of the transformer primary winding into the capacitor, thereby not only protecting the collector of the transistor but adding the back EMF energy to the charge in the capacitor for higher efficiency. High spark rates (nominal 750 sparks per minute) are achieved.

Abstract: In an ignition device, a preheater in the wall of a carburetor is connectable to an ignition heater in series and the heaters are controlled by the switching operation of relay contacts. Both heaters are connectable in series during the ignition operation to limit current flowing to the ignition heater.

Abstract: An electrical ignition system for a burner in which a spark generation circuit is arranged to charge a capacitor in one sense, and in which a flame sensing device charges the capacitor in the opposite sense, a detector circuit being provided to monitor the presence and polarity of a charge on the capacitor.

Abstract: An oil burner primary control in an interrupted ignition burner control system includes a regulating circuit for regulating the voltage across a flame-responsive photo-conductive cell. The regulating circuit ensures that, in the event the cell becomes defective so as to exhibit abnormal resistance characteristics, the system will not permit fuel to flow unless a burner flame exists or unless the igniter and a safety circuit are energized.

Abstract: Improved automatic ignition system (10) for gas fired devices such as boilers, clothes dryers, ranges, and the like. The system (10) is of the type including a variable resistance ignition means (16) having a particular temperature characteristic disposed in proximity to the burner (14) for igniting gas flowing therethrough when the ignition means (16) is energized. The improved system includes detection means (12) for repeatedly measuring the resistance of the ignition means (16) and for comparing such measurements, and activating means (12) for activating the gas valve opening means (56) to open the valve (60) when the detection means (12) establishes that the ignition means (16) is in the portion of its temperature characteristic where the temperature thereof is sufficient to ignite gas.

Abstract: An ignitor assembly for oil stoves is disclosed which includes an ignitor plug held in alignment with an exposed portion of a wick for firing the wick through the utilization of discharge originated from the ignitor plug. A light-sensitive element is disposed at a predetermined distance from the ignitor plug and in alignment with the exposed portion of the wick.

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: A control system for fluid fuel burners, particularly for blue-flame oil burners, utilizes flame conduction to control energizing of the light emitting portion of an optical coupler. Circuit means including the light responsive portion of the optical coupler is effective, in the presence of a predetermined level of illumination from the light emitting portion which occurs in the absence of a burner flame, to enable flow of a combustible fuel-air mixture and energizing of ignition means, and, in the subsequent absence of the predetermined level of illumination when burner flame exists, to terminate energizing of the ignition means and to enable continued flow of the combustible mixture. The control system further includes means for reducing the rate and level of illumination of the light emitting portion so that it requires a predetermined time period for the light emitting portion to be energized to the predetermined level of illumination.

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 electronic safety device for a fluid, particularly gaseous fuel burner of the intermittent operating type.The current supply to the electromagnetic valve controlling the input of gas to the burner is controlled by means of a switching transistor itself under the control of a bistable circuit. The inputs to this circuit receive signals translating the presence or the absence of certain operating conditions. The hysteresis properties of the electromagnetic valve are also used by means of an overvoltage circuit.This device may be applied to all heating apparatus, particularly those whose power supply source has a reduced capacity.

Abstract: An ignition system for use with a source of dc (or full-wave-rectified) power without the need for an inverter includes a flame sensing relay and a checking relay interlocked to achieve lockout if the proper starting sequence or timing are not met or if a flame-out occurs during operation. The checking relay is energized in response to a call-for-heat signal to isolate the flame detection circuitry from its source and commence a trial-for-ignition period in the flame detection circuitry which includes a timing circuit. The timing circuit actuates the flame-sensing relay during the trial-for-ignition period. The flame sensing relay energizes the fuel valve and a spark generator to ignite the fuel. If a flame is detected during the trial-for-ignition period by a flame probe, the timing circuit is disabled and operation continues until the call for heat is terminated as long as the flame is sensed. Another circuit senses flame at the spark gap and disables the spark gap generator after a flame is established.

Abstract: A circuit for safely admitting fuel to a burner, igniting the fuel, detecting the presence of flame at the burner, and preventing the escape of unburned fuel from the burner if ignition is not accomplished or the flame is interrupted. An initiation circuit operates a control signal generator during a time delay period and a valve operating circuit opens a fuel valve to admit fuel to a burner. An igniter circuit is operated in response to energization of the valve operating circuit to produce sparks for ignition of the fuel. A flame detector circuit powered by the valve operating circuit detects the presence of flame and, in response, the operation of the control signal generator is maintained and the operation of the ignition circuit is interrupted. The operation is fail-safe, the detection of flame is reliable despite power supply variations, and no power supply transformer or valve operating relay is required.

Abstract: A primary oil burner safety control and intermittent ignition system for initiating and supervising the combustion of fuel oil in furnaces, the system including thermostatic switch means controlling the energization of a relay having contacts controlling the energization of an oil burner, means constantly monitoring the state of the relay contacts with respect to the state of the thermostatic switch means, and means to effect safety shutdown of the oil burner in the event the state of the relay contacts disagrees with the state of the thermostatic switch means.

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 oil burner primary control in an interrupted ignition burner control system includes a miniature coupling transformer for controlling operation of the igniter. The gate circuit of a flame responsive switch is effective, in the absence of a burner flame, to generate a plurality of gating pulses at a frequency substantially greater than line frequency. The flame responsive switch is cyclically gated on by the pulses for energizing a safety switch resistance heater. The primary winding of the coupling transformer is connected in the gate circuit of the flame responsive switch and is responsive to the gating pulses to induce voltage pulses in its secondary winding which is connected in the gate circuit of an ignition switch controlling the igniter. At least one of the pulses occurs sufficiently early in each half cycle of the sine wave alternating current appearing at the ignition switch so that the ignition switch conducts during essentially all of the sine wave, as long as there is no burner flame.

Abstract: An apparatus for fuel ignition comprising an electrical source for providing electrical current; an electrically operated fuel ignition means; a valve means which allows passage of fuel to the ignition means when the valve means is opened; a first valve control means which will open the valve upon application of an electrical current and a second valve control means which will retain the valve means in an open position but will not initially open the valve upon application of an electrical current; an activating switch electrically connected between the electrical source and the rest of the apparatus so that the apparatus will not operate unless the activating switch is closed; a time delay switch connected between the activating switch and the rest of the apparatus and connected to an ignition sensing switch means so that the time delay switch stops the flow of electrical current to the rest of the apparatus if the ignition sensing switch means does not sense ignition within the time delay; and an ignition s

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.