Direct ignition gas burner control system

In a gas burner control system,

• a burner;
• electrically operated valve means for controlling flow of gas to said burner;
• circuit means for controlling operation of said valve means;
• an electrical igniter positioned in close proximity to said burner;
• gate-controlled solid state switch means connecting said igniter across a power source;
• flame-detect circuit means for generating voltage values indicative of absence and presence of current flow through a burner flame;
• and
• a microcomputer connected to said circuit means for controlling operation of said valve means, to said switch means, and to said flame-detect circuit means,
• said microcomputer being effective to control conduction of said switch means so as to effect energizing of said igniter to gas ignition temperature, to subsequently effect energizing of said valve means so as to cause flow of gas to said burner and ignition thereof, and to detect, store, and compare said voltage values generated by said flame-detect circuit means so as to effect immediate de-energizing of said igniter when said current flow through a burner flame appears, and to enable continued flow of gas to said burner so long as said burner flame is sustained,
• said valve means including a valve,
• said circuit means for controlling operation of said valve means including an electrical winding, a capacitor, and first and second controlled solid state switches,
• said switches being controlled by signals from said microcomputer and from an oscillator circuit,
• said switches being connected in circuit so as to enable said capacitor to charge when both said switches are non-conductive and to discharge through said winding and said first switch when said first switch is conductive and said second switch is non-conductive,
• said discharging of said capacitor being effective to open said valve.