Primary gas furnace control

Patent · Tue Dec 02 04:00:00 EST 1986

OSTI ID:7027394

Geary, F J

This patent describes a primary control for gas furnaces, and comprising a low voltage circuit adapted to be connected to a source of low voltage AC current, the low voltage circuit having a thermostatic switch therein. It also comprises an electrically operable pilot gas valve therein, an electrically operable main gas valve therein, relay means therein for controlling the energization of the main gas valve when a coil of the relay means is energized by a main valve control circuit portion of the low voltage circuit, and flame sensing means therein and disposed so as to be in the path of gas emanating from the pilot gas valve and being subjected to the heat of the gas flame thereof when the gas has been ignited. The flame sensing means has means for controlling the main gas valve by effecting the energization of the coil of the relay means when the flame sensing means is sensing the presence of the gas flame. The improvement described here is wherein the main valve control circuit portion has discharge capacitor means controlling the energization of the coil and has sustaining capacitor means connected in parallel with the coil and effective to maintain energization of the coil during recharging of the discharge capacitor means.

• Assignee: Robertshaw Controls Co., Richmond, VA
• Patent Number(s): US 4626192
• OSTI ID: 7027394
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
421000* -- Engineering-- Combustion Systems
ALTERNATING CURRENT
CAPACITORS
COMBUSTION CONTROL
CONTROL
CONTROL EQUIPMENT
CONTROL SYSTEMS
CURRENTS
ELECTRIC COILS
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTRONIC CIRCUITS
EQUIPMENT
FLAME PROPAGATION
FLOW REGULATORS
FURNACES
GAS FURNACES
RELAYS
THERMOSTATS
VALVES