Abstract: A method and apparatus for hydrocarbon flame ignition and detection is disclosed utilizing a pair of flame-detecting electrodes positioned at the flame site in contact with the flame and in a spaced-apart relationship to accommodate, in the gap therebetween, essentially the flame's reaction zone. At least one of the electrodes may additionally serve as the ignition element and is, accordingly, sufficiently electrically resistive so as to undergo self-heating in response to current flow therethrough.A second aspect of the invention relates to the direct application of AC line voltage across the resistive electrode during the ignition phase and across the electrode gap during the detection phase.A third aspect of the invention concerns the thermal-heating of both electrodes by the flame to reduce both the ignition time and the "wall quenching" effect of the otherwise cool electrode surface on the high-conductivity plasma in the reaction zone.

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, 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 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: A fuel ignition system that uses a high voltage spark generator and a flame rectification detecting circuit is disclosed. The system utilizes a voltage clipping means in the form of a neon tube to prevent the high voltage of the ignition system from interferring with the operation of the flame detection system even though both systems use a common spark gap.

Abstract: A flame responsive control circuit means has been disclosed which responds to the flame in a burner. The response is to the sudden rate of change of the resistance or impedance of a photocell upon the loss of flame. The two embodiments disclosed both utilize a rate of change sensing means to determine that a loss of flame has occurred. If a loss occurs, ignition is reinstituted immediately and the system either operates normally or locks itself out in a safety shut down.

Abstract: An electronic control system for safely operating a pair of redundant solenoid type valves is disclosed. The system utilizes an alternating current potential for energizing the valves. The first valve is energized across the applied potential and then is placed in series with the second valve. The series combination is selected so that once the valves are energized they will stay energized in the series configuration.

Abstract: A safety ignition valve for a pilotless burner comprises a valve body having an inlet for connection to a fuel supply, an outlet for connection to the burner and a valve seat between the inlet and outlet. A valve member is movable between a closed position in which it is seated on the valve seat and an open position in which it is spaced from the valve seat. A spring acting on the valve member biases it toward closed position. A first solenoid which is energized by current produced by a thermocouple heated by the burner acts on the valve member to hold it in open position against the bias of the spring. A second spring solenoid located in a control box fixed to the valve body actuates a plunger for moving the valve member to open position when the second solenoid is energized.

Abstract: An igniter and flame sensor electrode assembly which is suitable for mounting in a conventional thermocouple bracket in close proximity to a fuel burner so that the assembly can be employed in an ignition system to ignite the burner and sense a flame due to its conductive and/or rectification properties. The assembly is shaped similar to a conventional thermocouple and includes a tubular shaped probe having an ignition port in which the igniter element is mounted and a sleeve therearound which forms the flame sensing electrode. The housing for the igniter and flame sensor electrode is formed in two halves and the electrical connections to the flame sensing electrode and igniter element are made by lead wires located in axial bores within the housing.

Abstract: This invention relates to a particularly safe electrical control device for a gas or oil-fired heating appliance comprising a plurality of sub-circuits each carrying out part of a start-up sequence for the appliance, and arranged so that should any sub-circuit fail, the start-up sequence ceases.Parts of the control device are similar to those shown in British Patent Specification No. 1,314,185. (U.S.Pat. No. 3,674,410).

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: A circuit arrangement for utilizing the "flame (or hot gas) rectification" effect in an air gap is provided in which the air gap is defined between electrodes one of which is connected to a source of A.C. and the other of which is connected to earth or other suitable potential. A non-linear resistance device is connected in series with the air gap and a voltage sensing is provided for detecting a voltage across the non-linear resistance device, the arrangement being such that when no flame or hot gas is present in the air gap the air gap and the non-linear resistance device are virtually open-circuited so that the A.C's alternated by filter means to zero volts D.C. with a small ripple, superimposed thereon at the input to the voltage sensing circuit, whereas when flame or hot gas is present in said air gap the non-linear resistance produces a negatively predominant signal which after filtering provides a negative D.C. voltage shift with a small percentage A.C.

Abstract: A control arrangement for a direct ignition type fuel ignition system including a timing circuit having a timing capacitor which charges in response to application of power to the system defining a trial for ignition interval during which a controlled switching device is enabled to operate a flame relay to energize a fuel valve to supply fuel to a burner for ignition by sparks provided by a spark generator, the controlled switching device being disabled, deenergizing the flame relay when the timing capacitor becomes fully charged before the fuel is ignited, and the controlled switching device being maintained enabled through the action of a flame sensing circuit which is coupled to the timing circuit only when a flame is established.

Abstract: A flame detection system responsive to an arc triggering voltage in a spark gap having at least a portion located in a flame is used to control spark generating equipment. A pulse generator used to trigger the arc is inhibited upon detection of a lowered spark triggering voltage resulting from ignition of a flame.

Abstract: A delay circuit includes a switching element for operatively switching between a first position and a second position. The switching element connects an input voltage to an electrically-operated device in the first position. A delay element is operatively connected to the switching element for maintaining the switching element in the first position when an input voltage interruption occurs which is less than a pre-determined time interval.

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: Burner control apparatus includes control devices for actuating an ignition control means, and a timing circuit for providing an ignition timing sequence of four precise intervals. The timing circuit is actuated in response to a request for burner operation and the control devices are energized in sequence and combination in response to the actuated timing circuit. Time sequential pilot flame and main flame stabilization intervals are provided. If a signal from the flame sensor is received before the end of the overlapping flame stabilization timing intervals, the control device is energized and if flame detection signal is lost a lockout circuit is energized.

Abstract: A control circuit for use with spark ignition system disposed in a gas burner comprising a high voltage pulse circuit for developing the spark which is gated by a flame sensor. That same flame sensor also controls a timing and latch circuit connected to initially open the gas flow to the burner and to close such gas flow if burning is not established within a predetermined interval of time. The timing and latch circuit also includes components which after an unsuccessful start-up preclude further starting cycles until manual intervention takes place and control all failure modes to a shut-down condition.

Abstract: An electronic control system monitors, in a gas burner, the four functions of (1) initial ignition of the gas, (2) continued combustion of the gas, (3) the average time rate at which the gas is burned, and (4) the maximum temperature of the combustion chamber. A first comparator is responsive to a first thermosensitive element for controlling the average burning rate (or energy output) and the maximum temperature limit; a second comparator is responsive to a second thermosensitive unit for monitoring the flame of the burner, to sense initial and continued ignition; a third comparator functions as a timedelay circuit in association with the second comparator during an initial ignition procedure; and a fourth comparator controls the source of gas in response to the condition of the first and second comparators, so that gas is supplied only when both safe and necessary.

Abstract: A control circuit for a fuel ignition system of the direct ignition type for providing an interlock on start-up to prevent the energization of a fuel supply valve of the system under certain failure conditions includes an interlock relay which is energized, after a predetermined delay, over normally closed contacts of a flame relay to control a timing network to cause a flame sensing circuit to enable the flame relay to energize the valve during a trial for ignition interval defined by the timing network, the flame sensing circuit maintaining the flame relay, and thus the valve, energized when a flame is provided during the trial for ignition interval, the energization of the valve and the interlock relay being prevented if the normally closed contacts of the flame relay are open on start-up, and the delayed operation of the interlock relay preventing lockout of the system following momentary loss of power.

Abstract: Burner control apparatus includes a control device for actuating an ignition control means, and a timing circuit for providing an ignition timing interval of precise duration. 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.

Abstract: A fuel burner sequencing means is disclosed which utilizes a bistable or alternate action switching means for safety checking. The bistable switching means is specifically disclosed as a bistable relay that operates at the start of the cycle, and at the end of the cycle to check the operability of the safety checking means. This same bistable relay means is used as a lockout means in the event of the failure of flame when a flame should exist in the burner, or when a flame is indicated and none should be present.

Abstract: A flame detecting apparatus in which a detecting electrode is disposed in a flame, the base of a transistor is connected to the detecting electrode and biased with a predetermined DC voltage derived from a biasing circuit, the biasing circuit including a resistor and the impedance of the flame, an AC signal is applied to the emitter of the transistor, and an amplified AC signal is derived from the collector of the transistor as an output signal; the output signal being used as a control signal for a fuel supply control and/or an indicator.

Abstract: There is disclosed a thermally responsive switch that is ideally suited for responding to the ignition and extinguishment of a flame. The switch is provided with two switch poles, one that is biased normally open and the other that is biased normally closed. The response of the switch to the presence of a flame is very sensitive and precise to open the normally closed contact within a few seconds after ignition of a flame and, shortly thereafter within another controlled time period, to close the normally open contact. Upon extinguishment of the flame, the switch reverses its movement, opening the normally open contact within a short time interval, and, thereafter, closing the normally closed contact. The switch mechanism employs a thermally responsive, tube-in-tube member with the inner tube connected to a push rod which resiliently carries a switch lever.

Abstract: A fail-safe energizing circuit for effecting the operation of a functional device, such as a relay, includes a resistor and a capacitor connected between outputs of an AC signal source which supplies an AC signal for charging the capacitor, a normally disabled silicon controlled rectifier connected in shunt with the capacitor and an operate coil of the relay and operable when enabled to provide a discharge path for the capacitor permitting the capacitor to discharge over the relay coil to operate the relay, and a control circuit operable to provide an enabling signal derived from the AC signal for enabling the silicon controlled rectifier. The energizing circuit is described with reference to an application in an automatic fuel ignition system for controlling the operation of a relay which energizes a fuel valve of the system.

Abstract: A system for trial period ignition of a fluid fuel burner having an oscillator with a gate in the feedback path thereof, the oscillator providing power to a burner fuel valve and to a spark generator, wherein oscillator operation is sustained after the period only upon flame detection which keeps the oscillator feedback path gate closed.

Abstract: Apparatus including an improved D.C. operated oscillator for an intermediate power source, a cooperating solenoid gas valve opening and safety shut-off circuit, and a spark igniter with automatic shut-down.

Abstract: Flame supervisory method and apparatus in which a cross-checking relay system is controlled jointly by time-delay factors and a two-state control signal derived from the flame and having respectively pre-flame and flame-responsive polarity characteristics produced by reflexive bias and regenerative amplification and conversion of the basic flame-detection current to a control signal determining either switch-over to full flame burner operation or lock out of the system under ignition failure conditions. The two control states of the converted flame-detection signal are of a self-locking character, the pre-flame state tending to inhibit false response of the relay system to spurious flame signals, and the converted control signal in general being highly discriminative owing to an abrupt, non-linear change in polarity differentiating it from the pre-flame state.

Abstract: Fuel flow to a gas oven burner is controlled by a manual rotary valve and a series flow arranged, electrically operated valve and is ignited by a ceramic glow igniter. The electrically operated valve and glow coil are series connected across a power source through a manual line switch and an adjustable temperature responsive switching means. A control knob, when rotated, rotates the manual rotary valve, actuates the line switch, and adjusts the temperature responsive switching means.

Abstract: A fully automatic regulating equipment for a heating device having an oil vaporizing burner, for instance for a central heating furnace, comprises a thermostat responsive to the output hot water temperature or to the room temperature and having a contact which is arranged in series with an electronic time delay relay by which an ignition member activated by a surface thermostat, the bi-metallic heating winding of an oil control regulator and the excitation winding of a solenoid operated valve arranged in the pipeline leading to the burner can be switched to the main voltage. The equipment further comprises a thermo-relay arranged in series with the contact of the time delay relay and parallel to the excitation winding of the ignition member. The thermo relay is operated to switch the bi-metallic heating winding of the oil control regulator and the excitation winding of the solenoid operated valve with time delay with respect to the winding of the ignition member, to the main voltage.

Abstract: A vaporizing type liquid fuel combustion keyboards is disclosed which is particularly suitable for heating individual rooms and which includes a fuel supply system capable of delivering very small volumes of fuel reliably and without the need for excessively complicated components. The apparatus includes an intermittently driven electric fuel pump which is controlled by a flame detector for the the fuel feed at a proper level. An adjustable damper is also provided in the combustion air supply system for regulating the air flow delivered to the combustion apparatus, and is coupled to the fuel feed system for coordinating control thereof.

Abstract: In an exhaust gas purifying apparatus which includes first and second reactors in the exhaust line of an internal combustion engine there is provided a heater burner to which there is delivered an air-fuel mixture and which heats the first reactor for rapidly bringing it to operating temperatures when the engine is started. In the air conduit through which combustion air for the air-fuel mixture is delivered to the burner there is provided a valve controlled in such a manner that the flow rate of combustion air remains constant and is thus independent of the counterpressure at the heating burner and the output delivery of the air pump driving the combustion air. Upon reaching operating temperatures the burner is extinquished and the combustion air is rerouted past the first reactor to the second reactor.

Abstract: A fuel ignition control arrangement for use in a fuel ignition system includes a control circuit responsive to a thermostatically-controlled circuit element for the fuel ignition system for causing a gaseous fuel to be supplied to burner apparatus of the system, a spark-producing circuit responsive to the thermostatically-controlled element for igniting the fuel supplied to the burner apparatus, a timing circuit responsive to the thermostatically-controlled element for de-energizing the control circuit after a predetermined timing interval, and a flame sensing circuit responsive to the ignition of the fuel supplied to the burner apparatus for maintaining the control circuit in fuel supplying condition.

Abstract: A system for igniting, by a spark, the main burner of a gas fired device without the use of a pilot light from, for example, 12 or 24 volts. A unique oscillator provides the spark power and voltage. The oscillator also supplies the power to open the gas valve. A capacitor momentarily opens the valve. The valve is maintained open when a flame is present at the main burner.

Abstract: A solid state stack switch control system for furnaces and the like including burner control means, means including solid state means effective to control said burner control means in response to thermally actuated, magnetically operated heat detection means, line voltage safety switch means, and means for interfacing between an isolated low voltage control circuit and said burner control means.

Abstract: Primary control means for furnaces and the like including burner control means, means including solid state means effective to control said burner control means in response to a flame detector signal, bimetallic safety switch means, and means for interfacing between an isolated low voltage control circuit and said burner control means.