Safe start check circuit

Claim 1

A safe start check circuit for a fuel burner, including: flame response means adapted to sense a flame at a fuel burner and to provide an output signal upon the presence of a flame; gated solid state switch means responsive to said output signal; said solid state switch means connected in a series circuit with flame relay means to a source of electric potential with said relay means having a normally open contact and a normally closed contact; a first control circuit including said normally closed relay contact in series with a diode, and a capacitor which are connected across said source to provide a time delay; control relay means responsive to a charge stored in said capacitor and including a normally open contact and a normally closed contact; a control relay holding circuit comprising said normally open relay contacts, a second diode, and said control relay connected across the said source; terminal means connected to said second diode and said control relay with said terminal means adapted to connect said source to valve means for said fuel burner through both said normally open relay contacts; and said normally closed contact of said control relay means including connection means to effectively short circuit said gated solid state switch means through said valve means until said control relay means is energized to thereby assure that a safe condition exists before said flame relay means normally open contact can close to energize said valve means.