Patent US3564294A successfully refreshed from Google Patents.
US3564294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse welding circuits
Assignee: Welding Institute England
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Filing: 1968-06-07
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Granted: 1971-02-16
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Expires: 1988-06-07
Abstract
Abstract In a pulses current power supply utilizing a thyristor to supply current to a load and a commutating thyristor and capacitor for switching off the load-current thyristor, a transistor is pulsed in timed relation to triggering pulses applied to the two thyristors and is so connected in the commutating thyristor circuit that if the commutating thyristor is on when the transistor conducts the transistor switches the commutating thyristor off. This overcomes the problem of miscommutation, when an arc load is first applied, for example, which would otherwise leave both thyristors conducting.
Inventors
- 👤 Nigel C Balchin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:53
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/09; B23K9/091; H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/72; H03K17/73; H03K3/00; H03K3/02; H03K3/35; H03K3/352
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
159 words
A pulsed current power supply comprising: a first load current thyristor having anode, cathode and gate electrodes; a circuit branch connected across the anode-cathode electrodes of said thyristor and including a capacitor and a commutating thyristor having anode, cathode and gate electrodes, said capacitor being connected in series with the anode-cathode electrodes of said commutating thyristor; means for applying triggering pulses alternately to the gate electrodes of said two thyristors; a transistor connected in shunt with the anode-cathode electrodes of said commutating thyristor; and means for applying to said transistor a periodic control signal in timed relation to the triggering pulses to cause said transistor to conduct and thereby to reduce the potential across the anode-cathode electrodes of said commutating thyristor to a value below that necessary to maintain conduction, the said periodic control signals being applied to the transistor after the commutating thyristor has been triggered into conduction and before the next triggering pulse to the commutating thyristor.
Claim 2
Dependent Claim
159 words
A pulsed current power supply comprising: a first load current thyristor having anode, cathode and gate electrodes; a circuit branch connected across the anode-cathode electrodes of said thyristor and including a capacitor and a commutating thyristor having anode, cathode and gate electrodes, said capacitor being connected in series with the anode-cathode electrodes of said commutating thyristor; means for applying triggering pulses alternately to the gate electrodes of said two thyristors; a transistor connected in shunt with the anode-cathode electrodes of said commutating thyristor; and means for applying to said transistor a periodic control signal in timed relation to the triggering pulses to cause said transistor to conduct and thereby to reduce the potential across the anode-cathode electrodes of said commutating thyristor to a value below that necessary to maintain conduction, the said periodic control signals being applied to the transistor after the commutating thyristor has been triggered into conduction and before the next triggering pulse to the commutating thyristor.
Claim 3
Dependent Claim
37 words
A power supply in accordance with claim 1, including a first power supply connected to said first thyristor and further including an auxiliary power supply connected across said commutating thyristor and said transistor to charge said capacitor.
Claim 4
Dependent Claim
74 words
A power supply in accordance with claim 2, comprising a further transistor connected between said auxiliary supply, on the one hand, and said commutating thyristor and first transistor, on the other hand, and means for applying periodic control signals to said further transistor in timed relation with the triggering signals to render said further transistor nonconducting when said first transistor is conducting and thereby to increase the speed of switching off said commutating thyristor.
Claim 5
Dependent Claim
160 words
A pulsed current power supply comprising: a first thyristor having anode, cathode and gate electrodes; a circuit branch connected across the anode-cathode electrodes of said first thyristor and including a capacitor and a commutating thyristor having anode-cathode and gate electrodes, said capacitor being connected in series with the anode-cathode electrodes of said commutating thyristor; means for applying triggering pulses alternately to the gate electrodes of said thyristors; a power supply circuit for said commutating thyristor, said circuit including a power supply and a transistor, the emitter-collector path of said transistor being connected in series between said commutating thyristor and said power supply; and means for applying to said transistor periodic control signals in timed relation to the triggering pulses to render said transistor nonconducting and thereby to switch ofF said commutating thyristor, the periodic control signals being applied to said transistor after said commutating thyristor has been triggered into conduction and before the next triggering pulse to said commutating thyristor.
Claim 6
Dependent Claim
160 words
A pulsed current power supply comprising: a first thyristor having anode, cathode and gate electrodes; a circuit branch connected across the anode-cathode electrodes of said first thyristor and including a capacitor and a commutating thyristor having anode-cathode and gate electrodes, said capacitor being connected in series with the anode-cathode electrodes of said commutating thyristor; means for applying triggering pulses alternately to the gate electrodes of said thyristors; a power supply circuit for said commutating thyristor, said circuit including a power supply and a transistor, the emitter-collector path of said transistor being connected in series between said commutating thyristor and said power supply; and means for applying to said transistor periodic control signals in timed relation to the triggering pulses to render said transistor nonconducting and thereby to switch ofF said commutating thyristor, the periodic control signals being applied to said transistor after said commutating thyristor has been triggered into conduction and before the next triggering pulse to said commutating thyristor.
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) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |