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: A gas burner control system utilizes an electrical resistance igniter to ignite a main burner. Electronic sensing means is located adjacent the burner and adjacent a portion of the igniter where opposite voltage polarity exists between the igniter and sensing means. Current flows from the igniter to the sensing means when the igniter is heated above ignition temperature. Circuit means is responsive to such current flow to de-energize the igniter and enable gas to flow for a timed trial ignition period, the igniter having sufficient mass to remain at or above ignition temperature for the trial ignition period. When ignition occurs, the circuit means is responsive to current flow through burner flame from the sensing means to the burner to maintain gas flow.

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 burner control system for a hot water boiler is responsive to both outlet water temperature and return water temperature to provide a relatively constant outlet water temperature regardless of variations in heat output requirements. A first thermistor responsive to return water temperature is effective to provide on-off control of gas flow to the burner. A second thermistor responsive to outlet water temperature is effective to vary the rate of gas flow to the burner so as to maintain a predetermined outlet water temperature. A timing circuit is effective each time the burner is turned on to delay a high rate of gas flow to the burner.

Abstract: An air flow responsive switching means controlling "on" and "off" operation of an electrostatic air cleaner comprises a controlled solid state switch having gating means including a thermistor arranged to be cooled by air flow. The thermistor is incorporated with the high voltage power supply circuit in a casing for convenient removal and replacement.

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 spark ignition circuit begins producing sparking pulses and a storage capacitor begins charging upon closure of a space thermostat. An electromagnetically operated valve controlling gas flow to a burner is energized sufficiently to open only upon discharge of the capacitor and a parallel holding circuit holds open the valve and prevents recharging of the capacitor.A counting circuit, including a first monostable multivibrator, responds to each sparking pulse to effect incremental charging of a capacitor. Circuit means, including a programmable unijunction transistor and a second monostable multivibrator, responds to each occurrence of a predetermined charge on the capacitor to produce an output pulse comprising negative and positive signal voltages occurring in that order. Switching means responding to the positive signal of the first occurring output pulse effects the discharge of the storage capacitor and completion of the holding circuit, whereby the valve is open.

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.