US3876924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved gating circuit for thyristor power supply
Assignee: Environment One Corp
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Filing: 1973-03-12
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Granted: 1975-04-08
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Expires: 1993-03-12
Abstract
Abstract An improved gating control circuit for gate controlled thyristor power supplies comprising a programmable uni-junction transistor having an anode, an anode-gate and a cathode, a timing capacitor connected in parallel circuit relationship across the anodecathode of the programmable uni-junction transistor, and an output circuit coupled in series circuit relationship with the programmable uni-junction transistor for supplying a gating-on signal to the control gate of a gate controlled power thyristor. An adjustable charging resistor is connected in common to the anode of the programmable uni-junction transistor and to the timing capacitor and an anode-gate biasing resistor is connected across the series connected charging resistor and programmable uni-junction transistor with an intermediate point of the biasing resistor connected to the anode-gate of the programmable unijunction transistor. A power supply terminal is connected across the biasing resistor for supplying the gating control circuit with low voltage direct current excitation potential.
Inventors
- 👤 Jr Philip H Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:52
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/06; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/5157; H02M7/525
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
249 words
A gating circuit for a thyristor power supply system having high voltage power supply terminal means, means for deriving a low voltage unidirectional self-excitation potential from the high voltage power supply terminal means, timing circuit charging means supplied by said low voltage excitation potential, voltage responsive switching means, gate controlled semiconductor switching means connected intermediate said low voltage excitation potential and said timing circuit charging means for controlling application of said low voltage excitation potential to said timing circuit charging means, the control gate of said semiconductor switching means being coupled to and controlled by the voltage across the thyristor power supply for controlling supply of the low voltage excitation potential to the timing circuit charging means, said voltage responsive switching means being rendered conductive upon the voltage across said timing circuit charging means attaining a preset value, a constant current, high voltage gate controlled semiconductor switching means having a relatively flat current vs. voltage conducting characteristic having its load terminals connected to and supplied by said high voltage power supply terminals, the control gate of said constant current high voltage switching device being coupled to and controlled by said voltage responsive switching means, and gating signal output circuit means connected in series circuit relationship with the load terminals of said constant current high voltage semiconductor switching means, said gating signal output circuit means being adapted for connection to the control gate of a gate controlled thyristor of large power rating comprising a part of the thyristor power supply.
Claim 2
Dependent Claim
249 words
A gating circuit for a thyristor power supply system having high voltage power supply terminal means, means for deriving a low voltage unidirectional self-excitation potential from the high voltage power supply terminal means, timing circuit charging means supplied by said low voltage excitation potential, voltage responsive switching means, gate controlled semiconductor switching means connected intermediate said low voltage excitation potential and said timing circuit charging means for controlling application of said low voltage excitation potential to said timing circuit charging means, the control gate of said semiconductor switching means being coupled to and controlled by the voltage across the thyristor power supply for controlling supply of the low voltage excitation potential to the timing circuit charging means, said voltage responsive switching means being rendered conductive upon the voltage across said timing circuit charging means attaining a preset value, a constant current, high voltage gate controlled semiconductor switching means having a relatively flat current vs. voltage conducting characteristic having its load terminals connected to and supplied by said high voltage power supply terminals, the control gate of said constant current high voltage switching device being coupled to and controlled by said voltage responsive switching means, and gating signal output circuit means connected in series circuit relationship with the load terminals of said constant current high voltage semiconductor switching means, said gating signal output circuit means being adapted for connection to the control gate of a gate controlled thyristor of large power rating comprising a part of the thyristor power supply.
Claim 3
Dependent Claim
72 words
A gating circuit according to claim 1 wherein said constant current high voltage gate controlled semiconductor switching means comprises a high voltage switching transistor having a relatively flat current vs. voltage conducting characteristic with the emitter-collector of the transistor being connected in series with the gating signal output circuit means across the high voltage power supply terminal means and the base of the transistor being connected to the voltage responsive switching means.
Claim 4
Dependent Claim
35 words
A gating circuit according to claim 2 wherein the voltage responsive switching means comprises a programmable unijunction transistor device and further including means for varying the charging time constant of said timing circuit charging means.
Claim 5
Dependent Claim
35 words
A gating circuit according to claim 2 wherein the voltage responsive switching means comprises a silicon unilateral switch device and further including means for varying the charging time constant of said timing circuit charging means.
Claim 6
Dependent Claim
61 words
A gating circuit according to claim 2 wherein the gating signal output circuit means comprises an isolating transformer having its primary winding connected in the emitter-collector circuit of the high voltage switching transistor and having its secondary winding adapted to be connected to the control gate of a thyristor of large power rating comprising a part of the thyristor power supply.
Claim 7
Dependent Claim
131 words
A gating signal generator for gate controlled thyristors comprising a programmable uni-junction transistor having an anode, an anode-gate and a cathode, a timing capacitor connected in parallel circuit relationship across the anode-cathode of the programmable uni-junction transistor, output circuit means coupled in series circuit relationship with the programmable uni-junction transistor for supplying a gating-on signal to the control gate of a gate controlled thyristor, adjustable charging resistor means connected in common to the anode and to the timing capacitor, biasing resistor means connected across the series connected charging resistor and programmable uni-junction transistor and having an intermediate point connected to the anode-gate of the programmable uni-junction transistor, and supply terminal means connected across the biasing resistor means for supplying the gating signal generator with a low voltage direct current excitation potential.
Claim 8
Dependent Claim
131 words
A gating signal generator for gate controlled thyristors comprising a programmable uni-junction transistor having an anode, an anode-gate and a cathode, a timing capacitor connected in parallel circuit relationship across the anode-cathode of the programmable uni-junction transistor, output circuit means coupled in series circuit relationship with the programmable uni-junction transistor for supplying a gating-on signal to the control gate of a gate controlled thyristor, adjustable charging resistor means connected in common to the anode and to the timing capacitor, biasing resistor means connected across the series connected charging resistor and programmable uni-junction transistor and having an intermediate point connected to the anode-gate of the programmable uni-junction transistor, and supply terminal means connected across the biasing resistor means for supplying the gating signal generator with a low voltage direct current excitation potential.
Claim 9
Dependent Claim
42 words
A gating signal generator according to claim 6 further including enabling means connected in circuit relationship with said timing capacitor for initiating timing operation of said timing capacitor and load condition sampling means coupled to and controlling operation of said enabling means.
Claim 10
Dependent Claim
33 words
A gating signal generator according to claim 7 wherein said load condition sampling means includes differentiating circuit means for deriving a differentiated output electric control timing signal indicative of the load operating conditions.
Claim 11
Dependent Claim
55 words
A gating signal generator according to claim 8 wherein the enabling means comprises transistor means having its emitter-collector connected in series-circuit relationship with the parallel connected biasing resistor means and series connected charging resistor and timing capacitor and programmable uni-junction transistor, and having its base connected to the output from the load condition sampling means.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |