Electronic device adapted to produce high voltage-pulses, especially for igniting a gas lighter

Claim 2

An electronic ignition device for igniting fuel in cigarette lighters, gas burners and other fuel-consuming apparatus of the type provided with a burner unit and a spark gap arranged in proximity to the burner unit, comprising, in combination, a D.C. voltage source; voltage raising means connected to said source and to said spark gap and operative for generating a spark voltage across said spark gap, said voltage raising means including oscillator means connected to said source and operative for converting the D.C. voltage of said source into an oscillating voltage having a maximum voltage value higher than the voltage value of said D.C. voltage; switch means having an activated condition and an unactivated condition, and being operative when activated for initiating operation of said oscillator means to cause said voltage raising means to generate a spark voltage across said spark gap; and terminating means operative when said switch means remains in activated condition for automatically terminating operation of said oscillator means upon elapse of a predetermined time interval following the initiation of operation of said oscillator means.

Claim 3

An arrangement as defined in claim 1, wherein said terminating means comprises pulse-generating means operative for generating a pulse upon elapse of said predetermined time interval, and bistable means operative when in a first state for permitting operation of said oscillator means and operative when in a second state for preventing operation of said oscillator means, means connecting said switch means to said bistable means for causing said bistable means to undergo a transition to said first state in response to transitions of said switch means from unactivated to activated conditIon, and means connecting said pulse-generating means to said bistable means for causing said bistable means to undergo a transition to said second state in response to receipt of said pulse and to remain in said second state until such time as a transition of said switch means from unactivated to activated condition again occurs, wherein said bistable means comprises a thyristor circuit stage comprised of a bistable thyristor element.

Claim 4

An arrangement as defined in claim 1, wherein said terminating means comprises pulse-generating means operative for generating a pulse upon elapse of said predetermined time interval, and bistable means operative when in a first state for permitting operation of said oscillator means and operative when in a second state for preventing operation of said oscillator means, means connecting said switch means to said bistable means for causing said bistable means to undergo a transition to said first state in response to transitions of said switch means from unactivated to activated condition, and means connecting said pulse-generating means to said bistable means for causing said bistable means to undergo a transition to said second state in response to receipt of said pulse and to remain in said second state until such time as a transition of said switch means from unactivated to activated condition again occurs, wherein said pulse-generating means comprises means operative in response to activation of said switch means for applying to said bistable means a pulse train having a period equal to said predetermined time interval to cause said bistable means to undergo a transition to said second state thereof.

Claim 5

An arrangement as defined in claim 1, wherein said terminating means comprises pulse-generating means operative for generating a pulse upon elapse of said predetermined time interval, and bistable means operative when in a first state for permitting operation of said oscillator means and operative when in a second state for preventing operation of said oscillator means, means connecting said switch means to said bistable means for causing said bistable means to undergo a transition to said first state in response to transitions of said switch means from unactivated to activated condition, and means connecting said pulse-generating means to said bistable means for causing said bistable means to undergo a transition to said second state in response to receipt of said pulse and to remain in said second state until such time as a transition of said switch means from unactivated to activated condition again occurs, wherein said pulse-generating means comprises means for generating a pulse each time a spark voltage is generated across said voltage gap so as to thereby generate a pulse train, and frequency-divider means having an input connected to receive said pulse train and having an output constituting the output of said pulse-generating means.

Claim 6

An arrangement as defined in claim 1, wherein said terminating means comprises means automatically operative for terminating operation of said oscillator means upon generation of said spark voltage across said spark gap.

Claim 7

An arrangement as defined in claim 1, wherein said terminating means comprises means automatically operative for terminating operation of said oscillator means in response to the generation of a predetermined number of successive spark voltages across said spark gap.

Claim 8

An arrangement as defined in claim 1., wherein said terminating means comprises pulse-generating means operative for generating a pulse upon elapse of said predetermined time interval, and bistable means operative when in a first state for permitting operation of said oscillator means and operative when in a second state for preventing operation of said oscillator means, means connecting said switch means to said bistable means for causing said bistable means to undergo a transition to said first state in response to transitions of said switch means from unactivated to activated condition, And means connecting said pulse-generating means to said bistable means for causing said bistable means to undergo a transition to said second state in response to receipt of said pulse and to remain in said second state until such time as a transition of said switch means from unactivated to activated condition again occurs, wherein said pulse-generating means comprises means for generating said pulse in response to the generation of a predetermined plurality of successive spark voltages across said spark gap.

Claim 9

An arrangement as defined in claim 1., wherein said terminating means includes a timing capacitor, and wherein said switch means comprises means operative when said switch means is in unactivated condition for connecting said timing capacitor to said D.C. voltage source to charge said capacitor, and means operative when said switch means is in activated condition for applying the voltage across said timing capacitor to said voltage-raising means to effect operation of said oscillator means until such time as the voltage across said capacitor falls below a predetermined value, and wherein said terminating means further comprises discharging means operative for discharging said timing capacitor when said switch means is in activated condition.

Claim 10

An arrangement as defined in claim 1., wherein said voltage-raising means comprises an inductance connected in the oscillator circuit and periodically energized by current controlled by said oscillator.

Claim 11

An arrangement as defined in claim 9., wherein said inductance is comprised of a ferrite core and a coil wound on said core.

Claim 12

An arrangement as defined in claim 9., wherein the overvoltage coefficient of said inductance is at least 100.

Claim 13

An arrangement as defined in claim 1., wherein said voltage-raising means comprises a transformer having a primary winding connected in the circuit of said oscillator means and periodically energized by oscillating current controlled by said oscillator means, so as to cause generation of said oscillating voltage across the secondary winding of the transformer, and means connecting said secondary winding to said spark gap.

Claim 14

An arrangement as defined in claim 1., wherein said voltage-raising means further comprises a transistor amplifier stage comprised of an amplifier transistor, and wherein said oscillator means comprises a transistor oscillator stage comprised of an oscillator transistor, and means connecting the output of said transistor amplifier stage to the base of said oscillator transistor, and wherein said switch means comprises means operative when said switch means is activated for applying to said transistor amplifier stage a signal which in amplified form is applied by the latter to said base to initiate operation of said oscillator means.

Claim 15

An arrangement as defined in claim 13, wherein said voltage-raising means further comprises a high-overvoltage-coefficient inductance connected in the collector circuit of said oscillator transistor and periodically energized by oscillating current.

Claim 16

An arrangement as defined in claim 13, wherein said terminating means includes a timing capacitor, and wherein said switch means comprises means operative when said switch means is in unactivated condition for connecting said timing capacitor to said D.C. voltage source to charge said capacitor, and means operative when said switch means is in activated condition for applying the voltage across said timing capacitor to the base of said amplifier transistor, and wherein said terminating means further comprises discharge resistance means in the circuit formed by said timing capacitor and said amplifier transistor.

Claim 17

An arrangement as defined in claim 14., wherein said voltage-raising means further includes another inductance having a lesser number of turns and connected in the base circuit of said oscillator transistor, the two inductances being wound around a common core.

Claim 18

An arrangement as defined in claim 8., wherein said discharging means comprises a field-effect transistor having a drain-gate current path connectable via said switch means to said timing capacitor to provide a path for timing capacitor discharge current, and wherein said voltage-raising means comprises an oscillator transistor and an amplifier transistor electrically interconnected with each other and an inductance in the output circuit of said oscillator transistor, and means connecting an output electrode of said field-effect transistor to an input electrode of said amplifier transistor for causing latter to apply a signal to the base of said oscillator transistor to render said oscillator means operative when said timing capacitor discharges through said drain-gate current path.

Claim 19

An arrangement as defined in claim 14., wherein said inductance constitutes the primary winding of a transformer, and wherein said voltage-raising means further includes a secondary winding cooperating with said primary winding, and a further winding connected in the base circuit of said oscillator transistor and inductively coupled with said secondary winding so as to act as an additional primary winding of said transformer.

Claim 20

An arrangement as defined in claim 1., wherein said voltage-raising means comprises a capacitor, charging means connected to receive said oscillating voltage and operative for applying a charging voltage to said capacitor to charge the latter, a transformer having a secondary winding connected across said spark gap and having a primary winding, an electronic switch connecting together said capacitor and said primary winding to form a capacitor discharge path when said electronic switch is conductive, and discharge-initiating means for automatically effecting capacitor discharge by rendering said electronic switch conductive after a build-up of charge on said capacitor.

Claim 21

An arrangement as defined in claim 19., wherein said terminating means comprises pulse-generating means operative for generating a pulse upon elapse of a time interval which is physically independent of the time interval required for said build-up of charge and for said discharge and which furthermore constitutes said predetermined time interval, and bistable means operative when in a first state for permitting operation of said oscillator means and operative when in a second state for preventing operation of said oscillator means, means connecting said switch means to said bistable means for causing said bistable means to undergo a transition to said first state in response to transitions of said switch means from unactivated to activated condition, and means connecting said pulse-generating means to said bistable means for causing said bistable means to undergo a transition to said second state in response to receipt of said pulse and to remain in said second state until such time as a transition of said switch means from unactivated to activated condition again occurs.

Claim 22

An arrangement as defined in claim 20, wherein said bistable means comprises a bistable circuit stage including two transistors of opposite conductivity types, each of the two transistors having a base connected to the collector of the other of the two transistors, and said transistors being connected to said oscillator means for permitting and preventing operation of said oscillator means in dependence upon the conductivity of said transistors.

Claim 23

An arrangement as defined in claim 19., wherein said predetermined time interval is a multiple of the time interval required for said build-up of charge and for said discharge, whereby a plurality of spark voltages are generated across said spark gap prior to termination of operation of said oscillator means.

Claim 24

An arrangement as defined in claim 19, wherein said predetermined time interval is greater than and physically independent of the time interval required for said build-up of charge and for said discharge.

Claim 25

An arrangement as defined in claim 19, wherein said charging means comprises a charging rectifier, and wheRein said electronic switch is a thyristor.

Claim 26

An arrangement as defined in claim 19., wherein said discharge-initiating means comprises means operative for rendering said electronic switch conductive when the voltage across said capacitor reaches a predetermined value.

Claim 27

An arrangement as defined in claim 19., wherein said electronic switch is a thyristor, and wherein said discharge-initiating means comprises means for automatically rendering said thyristor conductive when the voltage across said capacitor reaches a predetermined value, and including a Zener diode having a cathode connected to the anode of said thyristor and an anode connected to the gate of said thyristor, and a resistor connected between the gate of said thyristor and the cathode of said thyristor.

Claim 28

An arrangement as defined in claim 1., wherein said source of D.C. voltage is a battery.

Claim 29

An arrangement as defined in claim 1., wherein said source of D.C. voltage is a rechargeable accumulator.

Claim 30

An arrangement as defined in claim 28., and further including means for charging said accumulator.

Claim 31

An arrangement as defined in claim 2., wherein said bistable thyristor element is a tetrode thyristor.

Claim 32

An electronic ignition device for igniting fuel in cigarette lighters, gas burners and other fuel-consuming apparatus of the type provided with a burner unit and a spark gap arranged in proximity to the burner unit, comprising, in combination, a D.C. voltage source; voltage raising means connected to said source and to said spark gap and operative for generating a spark voltage across said spark gap, said voltage raising means including oscillator means connected to said source and operative for converting the D.C. voltage of said source into an oscillating voltage having a maximum voltage value higher than the voltage value of said D.C. voltage; switch means having an activated condition and an unactivated condition, and being operative when activated for initiating operation of said oscillator means to cause said voltage raising means to generate a spark voltage across said spark gap; and terminating means automatically operative for terminating operation of said oscillator means upon elapse of a predetermined time interval following the initiation of operation of said oscillator means.

Claim 33

An electronic ignition device for igniting fuel in cigarette lighters, gas burners and other fuel-consuming apparatus of the type provided with a burner unit and a spark gap arranged in proximity to the burner unit, comprising, in combination, a D.C. voltage source; voltage raising means connected to said source and to said spark gap and operative for generating a spark voltage across said spark gap, said voltage raising means including oscillator means connected to said source and operative for converting the D.C. voltage of said source into an oscillating voltage having a maximum voltage value higher than the voltage value of said D.C. voltage; switch means having an activated condition and an unactivated condition, and being operative when activated for initiating operation of said oscillator means to cause said voltage raising means to generate a spark voltage across said spark gap; and terminating means automatically operative for terminating operation of said oscillator means upon elapse of a predetermined time interval following the initiation of operation of said oscillator means.