Electric igniter system

Claim 2

An electric ignition system for a fuel burner comprising input means adapted to be connected with an electrical power source, an electric ignitor coupled to said input means and adapted to be located within igniting proximity of the burner, said igniter having a negative temperature coefficient of resistance, a resistor having a positive temperature coefficient of resistance coupled in series with said igniter and adapted to be heated thereby, an electrically operated valve adapted to control a flow of fuel to the burner, and means coupled to said ignitor, said resistor, and said valve and responsive to the relative resistances of said ignitor and said resistor for enabling energization of said valve to establish a flow of fuel when said ignitor is above fuel igniting temperatures and for disabling said valve upon failure of said ignitor.

Claim 3

The invention as recited in claim 1 wherein said means includes an electric relay having an energization winding and a switch responsive thereto, said switch being coupled in series with said valve to form a series circuit.

Claim 4

The invention as recited in claim 2 wherein said series circuit is coupled in parallel with said resistor, and said energization winding is coupled in parallel with said ignitor.

Claim 5

The invention as recited in claim 2 wherein said series circuit is coupled in parallel with said igniter and said energization winding is coupled in parallel with said resistor.

Claim 6

The invention as recited in claim 2 wherein said series circuit is coupled in parallel with said igniter and said energization winding is coupled in series with said resistor and said ignitor.

Claim 7

The invention as recited in claim 5 further including thermally responsive switch means connected with said valve and said relay, said thermally responsive switch means including a bimetallic element and an electric heater located within heating proximity of said bimetallic element and coupled with said ignitor.

Claim 8

The invention as recited in claim 6 wherein said thermally responsive switch means further includes a normally closed switch coupled in series with said valve and said relay switch and adapted to be opened by said bimetallic element in response to energization of said electric heater, and wherein said relay further includes a normally closed switch connected in series with said electric heater, said relay being initially actuated by said bimetallic element and being maintained in its actuated position by said energization winding whenever said ignitor is above fuel igniting temperature.

Claim 9

In an electric ignition system for a fuel burner, the combination comprising input means adapted to be connected to an electrical power source, an electric ignitor adapted to be located adjacent the burner and coupled to said input means, said ignitor having a negative temperature coefficient of resistance thereby producing a temperature dependent voltage drop thereacross, an electrically operated valve adapted to control a flow of fuel to the burner and being electrically coupled with said electric ignitor and said input means for energization by said power source when said ignitor is above fuel ignition temperature, switch means connecting said electrically operated valve with said ignitor whereby said valve is deenergized to thereby inhibit fuel flow therethrough whenever said ignitor develops an electrical short circuit, and circuit means connected with said ignitor and said switch means for disabling said valve to thereby inhibit fuel flow therethrough when said ignitor develops an electrical open circuit.

Claim 10

In an electric ignition system for a fuel burner, the combination comprising input means adapted to be connected to an electrical power source, an electric ignitor adapted to be located adjacent the burner and coupled to said input means, said ignitor having a negative temperature coefficient of resistance thereby producing a temperature dependent voltage drop thereacross, an electrically operated valve adapted to control a flow of fuel to the burner and being electrically coupled with said electric ignitor and said input means for energization by said power source when said ignitor is above fuel ignition temperature, switch means connecting said electrically operated valve with said ignitor whereby said valve is deenergized to thereby inhibit fuel flow therethrough whenever said ignitor develops an electrical short circuit, and circuit means connected with said ignitor and said switch means for disabling said valve to thereby inhibit fuel flow therethrough when said ignitor develops an electrical open circuit.

Claim 11

The invention as recited in claim 8 wherein said switch means connects said electrically operated valve across said igniter and wherein said circuit means is connected in series circuit with said ignitor, said switch means and said circuit means cooperating to inhibit actuation of said valve until said ignitor reaches fuel ignition temperatures.

Claim 12

The invention as recited in claim 9 wherein said circuit means comprises a resistor having a positive temperature coefficient of resistance and an energization winding of an electric relay coupled to form an electrical parallel circuit, and wherein said switch means comprises a normally open switch adapted to be closed in response to energization of said winding, said switch being coupled in series with said electrically operated valve.

Claim 13

The invention as recited in claim 9 wherein said circuit means comprises a resistor having a positive temperature coefficient of resistance and an energization winding of an electric relay coupled to form a series circuit, and wherein said switch means comprises a normally open switch adapted to be closed upon energization of said winding, said switch being coupled in series with said electrically operated valve. 12 The invention as recited in claim 11 wherein said energization winding is a holding coil, and wherein said switch means further includes thermally responsive switching means connected with said electrically operated valve and said normally open switch, said thermally responsive switch means including a bimetallic element and an electric heater located within heating proximity of said bimetallic element and coupled with said ignitor.

Claim 14

The invention as recited in claim 12 wherein said thermally responsive switching means further includes a normally closed switch coupled in series with said electrically operated valve and said normally open switch and adapted to be opened by said bimetallic element in response to energization of said electric heater, and wherein said relay further includes a normally closed switch connected in series with said electric heater, said relay being initially actuated by said bimetallic element and being maintained in its actuated position by said holding coil whenever said ignitor is above fuel igniting temperatures.