Claims
- 1. A spark ignitor for a combustible fuel, said ignitor comprising: a first junction; a first switch for connection to a conductor having a positive potential to said first junction; first and second inductive means each having first and second leads; a charging resistor connected from said first junction to said first inductive means first lead; a second switch for closure after said first switch is connected in parallel with said charging resistor; a silicon-controlled rectifier (SCR) having an anode, a cathode and a gate, said anode being connected from said first inductive means second lead; a diode having an anode connected from said SCR cathode, and a cathode connected to said second inductive means first lead, said second inductive means second lead being adapted for connection to a conductor of a negative potential; a main capacitor connected from said first inductive means first lead to said diode anode; said diode cathode being connected to said SCR gate; a second junction connected from said first inductive means first lead; starting means and hold off connected from said second junction to said SCR gate to fire said SCR when said second switch is closed; and conductor means connected with said first inductive means to establish an arc when the energy stored in said main capacitor is transferred to said first inductive means, said starting and hold off means including first and second resistors, a unijunction transistor having an emitter and first and second bases, an auxiliary capacitor, and third, fourth and fifth junctions, said first resistor being connected between said second and third junctions, said second resistor being connected between said third and fourth junctions, said SCR anode being connected from said fourth junction, said transistor second base being connected from said third junction, said transistor emitter being connected from said fifth junction, said auxiliary capacitor being connected from said fifth junction to said SCR gate, said transistor first base being connected to said SCR gate, said first and second inductive means including first and second transformers, respectively, each said transformer having primary and secondary windings, said first transformer primary winding having first and second ends connected to said first and second leads of said first inductive means, respectively, said second transformer primary winding having first and second ends connected to said first and second leads of said second inductive means, respectively, each of said secondaries having first and second leads, said conductor means including first and second spaced conductive structures, said first transformer primary having said first and second leads thereof connected to said first and second spaced conductive structures, respectively, to establish an arc therebetween, a main fuel burner, a gas valve having a winding actuable to supply fuel to said burner, said structures being in proximity to said burner to ignite fuel emanating therefrom by said arc, and means connected from said second transformer primary for actuating said valve.
- 2. The invention as defined in claim 1, wherein one of said structures includes a ground for said main burner, first, second and third capacitors, first and second resistors, a flame rod supported over said main burner, first and second diodes, a differential amplifier having noninverting and inverting input leads, an output lead, and power input and output leads, first, second, third, fourth, fifth and sixth junctions, said second transformer secondary second lead being connected to said fifth, sixth and seventh junctions and to ground, said first capacitor being connected between said first and second junctions, said flame rod being connected from said second junction, said first resistor being connected between said second and third junctions, said second resistor being connected between said third and sixth junctions, said second capacitor being connected between said third and fourth junctions, said third capacitor being connected between said fourth and fifth junctions, said amplifier output lead being connected to said seventh junction, said inverting input lead being connected from said seventh junction, said noninverting input lead being connected from said fourth junction, said first diode and said gas valve winding being connected in series between said fifth and seventh junctions, said first diode being poled to be conductive toward said seventh junction, said second diode being connected between said first and fourth junctions and being poled to be conductive toward said first junction, said power input lead being connected from said fourth junction, said power output lead being grounded.
- 3. Apparatus for periodically producing first signal portions of a higher frequency and for periodically producing second signal portions alternately with said first signal portions, said second signal portions being of a frequency lower than said higher frequency, said apparatus comprising: means for providing a source of potential including first and second leads; a circuit connected between said first and second leads, said circuit including first, second and third junctions, first and second inductor means, a capacitor, a silicon-controlled rectifier (SCR) having an anode, a cathode and a gate, and a diode, said first lead being connected to said first junction, said first inductor means being connected from said first junction to said SCR anode, said capacitor being connected between said first and second junctions, said SCR cathode being connected to said second junction, said diode being connected between said second and third junctions and being poled to be conductive toward said third junction, said second inductor means being connected from said third junction to said second lead, said SCR gate being connected from said third junction; and utilization means coupled to said circuit, said utilization means including spark electrode means for ignition of a combustible fuel, said utilization means also including a burner, a valve connected to said burner to control the supply of said fuel thereto, said valve having a solenoid-type operator coupled to said circuit in a manner to open said valve when a predetermined voltage is supplied to said circuit over said first and second leads.
- 4. Apparatus for periodically producing first signal portions of a higher frequency and for periodically producing second signal portions alternately with said first signal portions, said second signal portions being of a frequency lower than said higher frequency, said apparatus comprising: means for providing a source of potential including first and second leads; a circuit connected between said first and second leads, said circuit including first, second and third junctions, first and second inductor means, a capacitor, a silicon-controlled rectifier (SCR) having an anode, a cathode and a gate, and a diode, said first lead being connected to said first junction, said first inductor means being connected from said first junction to said SCR anode, said capacitor being connected between said first and second junctions, said SCR cathode being connected to said second junction, said diode being connected between said second and third junctions and being poled to be conductive toward said third junction, said second inductor means being connected from said third junction to said second lead, said SCR gate being connected from said third junction; and utilization means coupled to said circuit, at least one of said inductor means including a first transformer having a primary winding connected in said circuit, and a secondary winding connected to said utilization means, the other of said inductor means including a second transformer having a primary winding connected in said circuit, and a secondary winding connected to said utilization means, said utilization means including spark electrode means for ignition of a combustible fuel connected from said first transformer secondary, said utilization means also including a burner, a valve connected to said burner to control the supply of said fuel thereto, said valve having a solenoid-type operator coupled to said circuit in a manner to open said valve when a predetermined voltage is supplied to said circuit over said first and second leads, said operator being connected from said second transformer secondary.
- 5. The invention as defined in claim 4, wherein said predetermined voltage is a D.C. voltage.
- 6. The invention as defined in claim 4, wherein said predetermined voltage is an A.C. voltage.
- 7. Fuel-burning apparatus comprising: a burner; first means actuable to admit fuel to said burner; a spark ignitor actuable to cause combustion of fuel at said burner; second means to supply a rectified output to said ignitor of an A.C. input voltage of a lower frequency, said ignitor including an oscillator adapted to oscillate at a fundamental frequency higher than said input voltage; third means responsive to an A.C. output voltage of said higher frequency to actuate said first means; and a transformer coupling said A.C. output voltage from said oscillator to said third means, said transformer having a ferrite core.
- 8. The invention as defined in claim 7, wherein said lower frequency is between about 50 Hz to 60 Hz, said higher frequency being much larger than said lower frequency.
- 9. The invention as defined in claim 8, wherein said higher frequency is about 1,000 Hz.
- 10. An electrical control system for supplying and igniting a combustible fuel, said system comprising: igniter means actuable to ignite the fuel; a burner; a fuel valve connected to said burner and having a winding actuable to allow fuel to enter said burner; first means connected from said igniter means to actuate said valve winding momentarily; a flame detector positioned adjacent said burner; and second means connected from said igniter means and said flame detector to actuate said valve winding continuously so long as said igniter means is in operation and a flame exists at said burner, said igniter means including an oscillator, said oscillator including a transformer having primary and secondary windings, said oscillator having a circuit including said primary winding, said secondary winding having first and second secondary leads, said first means including first and second capacitors connected across said secondary, a diode connected from the mutual junction of said first and second capacitors to one of said first and second secondary leads, and third means connecting one lead of one of said first and second capacitors other than that connected to said mutual junction to said valve winding.
- 11. An electrical control system for supplying and igniting a combustible fuel, said system comprising: igniter means actuable to ignite the fuel; a burner; a fuel valve connected to said burner and having a winding actuable to allow fuel to enter said burner; first means connected from said igniter means to actuate said valve winding momentarily; a flame detector positioned adjacent said burner; and second means connected from said igniter means and said flame detector to actuate said valve winding continuously so long as said igniter means is in operation and a flame exists at said burner, said igniter means including an oscillator, a junction being provided, said flame detector including a flame rod connected from said junction, said oscillator including a transformer having primary and secondary windings, said oscillator having a circuit including said primary winding, said secondary winding having first and second secondary leads, a capacitor connected between said first secondary lead and said junction, third means connecting said junction to said valve winding, and a resistor connected between said junction and said secondary lead.
- 12. The invention as defined in claim 10, wherein said flame detector includes a flame rod connected with one junction of said one lead of said one of said first and second capacitors other than said mutual junction thereof, and a resistor connected between said one junction and another junction with the other of said first and second capacitors other than said mutual junction thereof, and a third capacitor connected between one of said first and second secondary leads and said one junction.
Parent Case Info
This is a divisional application of copending application Ser. No. 447,889 filed Mar. 4, 1974 now U.S. Pat. No. 3,870,929. The benefit of the filing date of said copending application is, therefore, hereby claimed.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
Country |
Parent |
447889 |
Mar 1974 |
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