Patent ID: 6126435
Filing Date: 2000-10-03
Classification: F23N,F23Q

Abstract:
An electronic ignition system (10) for igniting a plurality of gas burners (12, 16, 18) which comprises:a spark generating circuit (32) to produce sparks for igniting each of said plurality of gas burners;a plurality of electrodes (20, 22, 24, 26, 28, 30), each one of said plurality of electrodes being connected with said spark generating circuit by a separate connection (34), said separate connection conducting a portion of said sparks to one of said plurality of electrodes, each one of said plurality of electrodes being mounted adjacent to a different one of said plurality of gas burners than the remainder of said plurality of electrodes, said one of said plurality of electrodes emitting said portion of said sparks for the ignition of the one of said plurality of gas burners to which said one of said plurality of electrodes is mounted adjacent;and a flame sensor circuit (44) connected between the spark generating circuit and at least one of the plurality of electrodes, which in a first period and once the spark generating circuit has been activated for producing said sparks, said flame sensor circuit is operated to detect the absence of flame on any of at least one of said plurality of gas burners, each of said at least one of the plurality of electrodes being mounted adjacent to one of said at least one of said plurality of gas burners, by means of said least one of the plurality of electrodes, and in a second period and once each of said plurality of gas burners has been ignited, said at least one of the plurality of electrodes and said flame sensor circuit are operated for sensing the presence of flame on said at least one of said plurality of gas burners, said flame sensor circuit possessing a power source through which energy is provided to said flame sensor circuit, a positive line (60) and a neutral line (62) being connected to the power source to provide energy to said circuit, wherein the flame sensor circuit comprises a circuit for applying a voltage between at least another of the plurality of electrodes and the burner to which said another of the plurality of electrodes is mounted adjacent, said circuit for applying a voltage being connected with the spark generating circuit to send a representative current signal for detecting the absence or presence of flame on said at least one of said plurality of gas burners; said circuit for applying the voltage comprising:a first resistor (R1), said first resistor being connected by one end to a first sensing line (52) in order to increase an input impedance to the flame sensor circuit, said first sensing line being connected to the spark generating circuit;a second sensing line (50), said second sensing line being connected with said at least one of the plurality of electrodes, said first sensing line and said second sensing line being used to effectuate the flame detection between an electrode and a burner;a second resistor (R3) connected in series with the first resistor (R1);an uncoupling device connected between a third line (54) connected to a frame of a stove and a neutral line (62) of the flame sensor circuit, in order that the neutral line not be directly connected to the frame of the stove;a transistor (N1), a base of said transistor (N1) being connected with the second resistor (R3) in order to provoke a polarization to said transistor, said transistor being connected with the neutral line that is feeding energy to the flame sensor circuit;a third resistor (R5) directly connected with a collector of said transistor (N1) for feeding the voltage of said flame sensor circuit;a first capacitor (C3) connected with the transistor (N1) and with the neutral line (62);a fourth resistor (R4) connected in parallel with the first capacitor (C3), to aid the second resistor (R3) in the polarization of the transistor (N1); and,a second capacitor (C1) connected with the first resistor (R1);said first resistor (R1), said third resistor (R5), and said uncoupling device, having parameters selected in order to rectify a voltage signal and to generate a continuous voltage which is subtracted from a sine signal generated by said second capacitor (C1), by said first capacitor (C3), by said second resistor (R3) and by the fourth resistor (R4), provoking in this way an inverse polarization of the transistor (N1), so that, the flame sensor circuit can be put in a cut position when the presence of flame is detected each of said at least one of said plurality of gas burners or in a saturation position when absence of flame is detected on any of said at least one of said plurality of gas burners.