Patent US3748536A successfully refreshed from Google Patents.
US3748536A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply
Assignee: Airco Inc
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Filing: 1972-09-05
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Granted: 1973-07-24
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Expires: 1992-09-05
Abstract
Abstract A power supply is described for an electron gun employed in an electron beam furnace system wherein the gun current is susceptible of rising upon the occurrence of an arc. Switching means including at least one transistor are coupled between the current source and the electron gun. The current through the transistor is sensed and control means operate to disable the transistor upon a rise in the current due to an arc.
Inventors
- 👤 S Andresen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:53
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/122; H02H7/1227; H01; H01J; H01J37/00; H01J37/02; H01J37/24; H01J37/241
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
120 words
A power supply for an electron gun employed in an electron beam furnace system wherein the gun current is susceptible of rising upon the occurrence of an arc, comprising, switching means adapted for connection to a source of alternating current, means coupled to said switching means for producing a direct current and for coupling same to the electron gun, said switching means including a pair of transistors and driving means for alternately rendering said transistors conductive, means for sensing the emitter-collector current of said transistors, and control means connected to said sensing means for shunting base current from said transistors upon a rise in the emitter-collector current of said transistors due to an arc, to thereby cut said transistors off.
Claim 2
Dependent Claim
120 words
A power supply for an electron gun employed in an electron beam furnace system wherein the gun current is susceptible of rising upon the occurrence of an arc, comprising, switching means adapted for connection to a source of alternating current, means coupled to said switching means for producing a direct current and for coupling same to the electron gun, said switching means including a pair of transistors and driving means for alternately rendering said transistors conductive, means for sensing the emitter-collector current of said transistors, and control means connected to said sensing means for shunting base current from said transistors upon a rise in the emitter-collector current of said transistors due to an arc, to thereby cut said transistors off.
Claim 3
Dependent Claim
15 words
A power supply according to claim 1 wherein said switching means comprise frequency increasing means.
Claim 4
Dependent Claim
30 words
A power supply according to claim 1 wherein said control means comprise a pair of silicon controlled rectifiers, each connected to the base of a respective one of said transistors.
Claim 5
Dependent Claim
29 words
A power supply according to claim 1 wherein said sensing means comprise a pair of emitter resistors, each connected in series with the emitter of one of said transistors.
Claim 6
Dependent Claim
51 words
A power supply according to claim 4 wherein said control means comprise a pair of silicon controlled rectifiers, each connected between the base and emitter of a respective one of said transistors, each of said silicon controlled rectifiers being connected with its gate and cathode across one of said emitter resistors.
Claim 7
Dependent Claim
102 words
A power supply for an electron gun employed in an electron beam furnace system wherein the gun current is susceptible of rising upon the occurrence of an arc, comprising, switching means adapted for connection to a source of alternating current, means coupled to said switching means for producing a direct current and for coupling same to the electron gun, said switching means including at least one transistor, means for sensing the emitter-collector current of said transistor, and control means connected to said sensing means for disabling said transistor upon a rise in the emitter current of said transistor due to an arc.
Claim 8
Dependent Claim
102 words
A power supply for an electron gun employed in an electron beam furnace system wherein the gun current is susceptible of rising upon the occurrence of an arc, comprising, switching means adapted for connection to a source of alternating current, means coupled to said switching means for producing a direct current and for coupling same to the electron gun, said switching means including at least one transistor, means for sensing the emitter-collector current of said transistor, and control means connected to said sensing means for disabling said transistor upon a rise in the emitter current of said transistor due to an arc.
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |