Electronic gas valve power interruption switch
AssigneeFasco Industries, Inc.
InventorsBryan L. Lakin, David B. Hyppio
Life of this patent
Estimating the term…
Abstract
An electronic safety circuit for a portable gas heater includes a transformer and half wave rectifier connected in parallel with a fan motor for charging a capacitor, and a solid state switching circuit, which may be either a pair of cascaded transistors, an SCR, or a Darlington switch, for applying a reverse polarity voltage across the solenoid of a solenoid operated gas valve to immediately turn off the gas valve in the event of loss of power to the combustion fan motor. The electronic safety circuit may be conveniently mounted on a PC board and enclosed in the combustion fan motor.
Claims26
In a gas appliance having a fan motor for supplying a quantity of air, a gas supply valve having a mechanically biased and electrically held actuator, and a thermocouple in circuit with said gas supply valve, said thermocouple having means for sensing the heat of combustion of said appliance and generating sufficient electrical power in response thereto to hold said electrical actuator in a closed position, the improvement comprising a solid state circuit having means for sensing an interruption of electrical power to said fan motor and means for applying a turn off signal directly to said electrical actuator in response thereto to thereby affirmatively turn off said gas supply valve.
A solid state safety circuit for applying a turn off signal to a solenoid operated gas supply valve upon interruption of electrical power to a fan motor, said circuit comprising means for sensing an interruption of electrical power to said fan motor, and means for applying a turn off signal to said gas supply valve in response thereto to thereby affirmatively turn off said gas supply valve.
A fan motor for a gas appliance, said gas appliance having a solenoid operated gas supply valve, said fan motor including a safety circuit mounted on a PC board, said PC board being mounted inside said fan motor, said safety circuit including means for applying a reverse polarity voltage to said valve upon interruption of power to said fan motor to thereby immediately turn said valve off.
Dependencies are inferred from the claim text.