US3821564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit for a thyristor
Assignee: ABB Norden Holding AB
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Filing: 1973-01-29
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Granted: 1974-06-28
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Expires: 1993-01-29
Abstract
Abstract A control circuit for a thyristor includes a voltage divider connected in parallel with the thyristor for feeding the control circuit. The voltage divider includes a resistor nearest the anode of the thyristor and in series with the resistor a parallel connection of a capacitor, a Zener-diode and a varistor. The feeding circuit of the control circuit is connected over such parallel connection. The resistor is dimensioned with regard to the desired current in the voltage divider, while the parallel connection is dimensioned to store in the condensor the necessary feeding voltage over the control circuit.
Inventors
- 👤 K Olsson
- 👤 G Lindblom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:09
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/08; H02M1/088; H02M1/096
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
230 words
A thyristor circuit comprising two end terminals for connecting the circuit to an outer voltage source, a main thyristor (1) connected to said end terminals with its anode and cathode, respectively, a control circuit (12-18) for said main thyristor, and a voltage divider (4-11) connected in parallel with said thyristor between said end terminals for feeding the control circuit with a voltage from said outer voltage source, said control circuit having an input circuit (13-18) for connection to an outer control device, and an output circuit (12) connected to a control electrode of said thyristor, said control circuit including means to transmit and amplify through its input and its output circuit a control pulse from said outer control device to said control electrode, said voltage divider including means to prevent overvoltages from said outer voltage source from being transmitted to said control circuit, said means comprising a first resistor (4) nearest to the anode of the thyristor and, in series with said resistor, a parallel connection of a capacitor (7), a Zener-diode (8) and a varistor (6), the control circuit (12-18) being connected to and fed from said parallel connection, said first resistor (4) being dimensioned with regard to the desired current in the voltage divider, said parallel connection being dimensioned to store in the condenser a predetermined voltage over the control circuit independent of variations in said outer voltage.
Claim 2
Dependent Claim
230 words
A thyristor circuit comprising two end terminals for connecting the circuit to an outer voltage source, a main thyristor (1) connected to said end terminals with its anode and cathode, respectively, a control circuit (12-18) for said main thyristor, and a voltage divider (4-11) connected in parallel with said thyristor between said end terminals for feeding the control circuit with a voltage from said outer voltage source, said control circuit having an input circuit (13-18) for connection to an outer control device, and an output circuit (12) connected to a control electrode of said thyristor, said control circuit including means to transmit and amplify through its input and its output circuit a control pulse from said outer control device to said control electrode, said voltage divider including means to prevent overvoltages from said outer voltage source from being transmitted to said control circuit, said means comprising a first resistor (4) nearest to the anode of the thyristor and, in series with said resistor, a parallel connection of a capacitor (7), a Zener-diode (8) and a varistor (6), the control circuit (12-18) being connected to and fed from said parallel connection, said first resistor (4) being dimensioned with regard to the desired current in the voltage divider, said parallel connection being dimensioned to store in the condenser a predetermined voltage over the control circuit independent of variations in said outer voltage.
Claim 3
Dependent Claim
37 words
A thyristor circuit according to claim 1, in which said capacitor (7) and Zener-diode (8) are connected in series with a diode (10), the conducting direction of which corresponds to the conducting direction of the thyristor (1).
Claim 4
Dependent Claim
34 words
A thyristor circuit according to claim 2, in which said diode (10) is connected in series with a second resistor (11) and said first resistor (4) is connected in series with a capacitor (5).
Claim 5
Dependent Claim
54 words
A thyristor circuit according to claim 1, in which said input circuit comprises at least one transistor (14), and in which, in order to avoid disturbance signals at the input circuit due to overvoltages in said voltage divider, a voltage derivative member (15) is connected to the input circuit to remove such disturbance signals.
Claim 6
Dependent Claim
28 words
A thyristor circuit according to claim 4, in which said voltage derivative member comprises a capacitor (15) connected in parallel with a transistor (14) at the input circuit.
Claim 7
Dependent Claim
31 words
In a thyristor circuit according to claim 4, said voltage derivative member comprising another transistor (20), controlled by the current in a second capacitor (21) connected to remove said disturbance signals.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |