US3609290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric arc control system
Assignee: LA-MARK CORP
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Filing: 1968-12-13
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Granted: 1971-09-28
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Expires: 1988-12-13
Abstract
Abstract An all solid-state electric arc starting and control system which may be used for electric welding or cutting operations. The control system includes a three-stage amplification of the output of a unijunction transistor relaxation oscillator. This produces a high frequency control current which regulates the main heavy duty welding current, and will serve to automatically restart the electric arc should the main welding current fail.
Inventors
- 👤 Gerald A Lawrence
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:59
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/10; B23K9/1006; B23K9/06; B23K9/067; B23K9/0672; B23K9/0673
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
147 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; said generating means including a relaxation oscillator; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said circuit for producing an electric arc having a first predetermined frequency including at least two inductance elements which are connected in series to an electric arc torch; and only one of said inductance elements being directly connected to said torch and being the electrical component through which said signals of said second predetermined frequency are introduced into said circuit for producing the electric arc having said first predetermined frequency.
Claim 2
Dependent Claim
147 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; said generating means including a relaxation oscillator; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said circuit for producing an electric arc having a first predetermined frequency including at least two inductance elements which are connected in series to an electric arc torch; and only one of said inductance elements being directly connected to said torch and being the electrical component through which said signals of said second predetermined frequency are introduced into said circuit for producing the electric arc having said first predetermined frequency.
Claim 3
Dependent Claim
132 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said means for generating said signals of a second predetermined frequency which is greater than said first predetermined frequency including a multiamplified unijunction transistor relaxation oscillator; and a power supply for said unijunction transistor relaxation oscillator which is of the half-wave nonfiltered type so that at least one of said signals occurs every other half cycle when the voltage is sufficiently high.
Claim 4
Dependent Claim
132 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said means for generating said signals of a second predetermined frequency which is greater than said first predetermined frequency including a multiamplified unijunction transistor relaxation oscillator; and a power supply for said unijunction transistor relaxation oscillator which is of the half-wave nonfiltered type so that at least one of said signals occurs every other half cycle when the voltage is sufficiently high.
Claim 5
Dependent Claim
152 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said means for generating said signals of the second predetermined frequency including a unijunction transistor relaxation oscillator; an amplifier circuit for amplifying the output of said unijunction transistor relaxation oscillator; said circuit for producing an electric arc having a first predetermined frequency including a reactor choke element; and a circuit for connecting said reactor choke element to said amplifier signal circuit to terminate the generation of said signals of said predetermined frequency when a current is flowing through said reactor choke element.
Claim 6
Dependent Claim
152 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said means for generating said signals of the second predetermined frequency including a unijunction transistor relaxation oscillator; an amplifier circuit for amplifying the output of said unijunction transistor relaxation oscillator; said circuit for producing an electric arc having a first predetermined frequency including a reactor choke element; and a circuit for connecting said reactor choke element to said amplifier signal circuit to terminate the generation of said signals of said predetermined frequency when a current is flowing through said reactor choke element.
Claim 7
Dependent Claim
72 words
An electric arc control system according to claim 3, characterized in that said impedance means connecting said generating means to said electric arc producing circuit includes a transformer, the primary winding of said transformer receiving the amplified output of said unijunction transistor relaxation oscillator, and the secondary winding of said transformer constituting a component within said circuit for producing an electric arc and being connected in series with an electric arc torch.
Claim 8
Dependent Claim
46 words
An electric arc control system according to claim 4, characterized in that said amplifier circuit for said unijunction transistor relaxation oscillator is a three-stage amplifier including one transistor and two silicon controlled rectifiers, and said system comprises an all solid-state electric arc starting and control system.
Claim 9
Dependent Claim
44 words
An electric arc control system according to claim 4, characterized in that each of said two silicon controlled rectifiers has its associated anode electrode connected to a capacitance element which in turn is connected to the cathode electrode of the respective silicon controlled rectifier.
Claim 10
Dependent Claim
150 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; said generating means including a relaxation oscillator; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said relaxation oscillator including a unijunction transistor; and circuit means for sensing the flow of electric current in said circuit for producing an electric arc having said first predetermined frequency and for controlling the output of said unijunction transistor relaxation oscillator whereby said signals of said second predetermined frequency are transmitted to said circuit for producing an electric arc only when no current is flowing in said circuit for producing an electric arc.
Claim 11
Dependent Claim
150 words
An electric arc control system comprising, in combination: a circuit for producing an electric arc having a first predetermined frequency; means for generating electric signals of a second predetermined frequency which is greater than said first predetermined frequency; said generating means including a relaxation oscillator; impedance means connecting said generating means to said electric arc producing circuit to superimpose said greater second predetermined frequency on said first predetermined frequency for controlling the operation of said electric arc; said relaxation oscillator including a unijunction transistor; and circuit means for sensing the flow of electric current in said circuit for producing an electric arc having said first predetermined frequency and for controlling the output of said unijunction transistor relaxation oscillator whereby said signals of said second predetermined frequency are transmitted to said circuit for producing an electric arc only when no current is flowing in said circuit for producing an electric arc.
Claim 12
Dependent Claim
53 words
An electric arc control system according to claim 7, characterized in that said circuit means for sensing the flow of electric current in said circuit for producing an electric arc includes a reactor choke element which also forms a component of said circuit for producing an electric arc having said first predetermined frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |