US3597580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled rectifier arc welding supply having improved positive firing characteristics
Assignee: Chemetron Corp
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Filing: 1969-04-25
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Granted: 1971-08-03
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Expires: 1989-04-25
Abstract
Abstract A three phase transformer and a full wave rectifier unit including silicon controlled power rectifiers. A feedback control system includes a pair of separate and cascaded summing differential amplifiers to control the firing circuits for the related pairs of rectifiers. Each firing circuit includes a unijunction transistor oscillator having a gate circuit including a small trim potentiometer for adjusting the pulse time. A capacitor in series with a resistor is connected in parallel with the oscillator to a bridge rectifier. A silicon controlled rectifier in series with a resistor is connected across the capacitor to form a firing pulse for the related pair of power rectifiers.
Inventors
- 👤 James B Stearns
- 👤 Robert W Wendelburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:42
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/06; B23K9/067; B23K9/0672; B23K9/0673; B23K9/10; B23K9/1006; B23K9/1043; B23K9/1056
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
151 words
A direct current arc power supply for establishing and maintaining an arc between a pair of electrode members, comprising a pair of electrode connecting terminals, a plurality of solid state triggered rectifier means connecting an alternating current input to a set of direct current output leads connected to said terminals for supplying the arc voltage and current to establish and maintain an arc, control means to establish a control signal for adjusting the arc current, a pulse forming means connected to said control means and establishing a train of time spaced pulses for controlling said rectifier means in accordance with the control signal, a discharge circuit including an energy storage means and a triggered electronic switch means, said triggered electronic switch means having an input means connected to said pulse forming means, and means connecting said triggered rectifier means to said discharge circuit to control the conduction of said rectifier means.
Claim 2
Dependent Claim
151 words
A direct current arc power supply for establishing and maintaining an arc between a pair of electrode members, comprising a pair of electrode connecting terminals, a plurality of solid state triggered rectifier means connecting an alternating current input to a set of direct current output leads connected to said terminals for supplying the arc voltage and current to establish and maintain an arc, control means to establish a control signal for adjusting the arc current, a pulse forming means connected to said control means and establishing a train of time spaced pulses for controlling said rectifier means in accordance with the control signal, a discharge circuit including an energy storage means and a triggered electronic switch means, said triggered electronic switch means having an input means connected to said pulse forming means, and means connecting said triggered rectifier means to said discharge circuit to control the conduction of said rectifier means.
Claim 3
Dependent Claim
91 words
The arc power supply of claim 1 wherein said rectifier means including a plurality of paralleled rectifying means and said pulse forming means includes a unijunction transistor connected in a pulse forming circuit, an amplifying means having an input control signal means and connected to the unijunction transistor to control the firing point thereof, said amplifying means including a transistor with a bias circuit including a fixed resistor in series with a small potentiometer for varying the firing point thereof and thereby balancing the current through the paralleled triggered rectifying means.
Claim 4
Dependent Claim
53 words
The direct current arc power supply of claim 1 wherein said pulse forming means includes a unijunction transisTor oscillator coupled to said alternating current input by a full wave rectifier means and a transformer means, said energy storage means being a capacitor connected in a charging circuit across said full wave rectifier means.
Claim 5
Dependent Claim
32 words
The direct current arc power supply of claim 3 having a voltage sensitive regulating device in parallel with the oscillator and a second voltage sensitive regulating device in parallel with the capacitor.
Claim 6
Dependent Claim
111 words
The arc power supply of claim 1 wherein said input includes a polyphase transformer means having a plurality of secondary phase windings, said triggered rectifier means including individual rectifying means connected one each in series with each phase winding and defining said pair of direct current output leads, said energy storage means including a storage capacitor means connected in parallel with the pulse forming means, said triggered electronic switch means being connected in series with a signal impedance in parallel with said capacitor means, a connection means connected to the input means of the triggered rectifier means and to the connection of said triggered electronic switch means and said signal impedance.
Claim 7
Dependent Claim
155 words
The direct current arc power supply of claim 1 wherein said rectifier means is a full wave three phase rectifier network having a pair of controlled rectifiers in each phase of the network, a three-phase input transformer connected to said rectifier network, said pulse forming means including three firing circuits one for each phase, each of said firing circuits including a related phase winding coupled to the corresponding primary phase of the input transformer and to a single phase full wave rectifier, a unijunction oscillator connected to said related phase winding and to said control circuit means, said energy storage means being a capacitor connected across the single phase full wave rectifier, said triggered electronic switch being a controlled rectifier and connected in series with an output resistor across said capacitor, the junction of said last named controlled rectifier and output resistor being connected to a pair of said controlled rectifiers in said rectifier network.
Claim 8
Dependent Claim
43 words
The direct current arc power supply of claim 6 having a Zener diode connected across the full wave rectifier to supply a regulated voltage to the oscillator, and a Zener diode connected across the capacitor to charge the capacitor to a selected voltage.
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |