US3573550A
Expired / Lapsed
US
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Automatically resetting transient protection device
Assignee: M&T Chemicals Inc
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Filing: 1969-03-07
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Granted: 1971-04-06
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Expires: 1989-03-07
Abstract
Abstract Apparatus for protecting electrical circuitry from voltage transients in a power supply or the like connected to the circuitry. A plurality of diodes and a silicon controlled rectifier are connected in series across the output of the power supply. The silicon controlled rectifier is triggered by a predetermined transient voltage level, and the output voltage of the power supply is clamped at the sum of the forward voltage drops of the diodes and controlled rectifier, the sum being set above the normal output voltage level of the power supply. The silicon controlled rectifier then commutates as soon as the transient ceases and the voltage level drops to normal. Various configurations are provided for DC or AC systems, as well as for remote sensing, and additional compensating circuits are employed for various applications.
Inventors
- 👤 Louis P Baker Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:58
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/04; H02H9/041; H02H3/00; H02H3/02; H02H3/06; H02H3/066; H02H9/005
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
84 words
A device for use in protecting electrical circuitry against voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a revErse biased triode thyristor, said thyristor including a gate electrode, and semiconductor device means for providing a biasing electrical potential connected in series with said thyristor when said thyristor is in a conducting state; and an energizing circuit having a predetermined voltage threshold of conduction, said energizing circuit being connected to said gate electrode.
Claim 2
Independent Claim
84 words
A device for use in protecting electrical circuitry against voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a revErse biased triode thyristor, said thyristor including a gate electrode, and semiconductor device means for providing a biasing electrical potential connected in series with said thyristor when said thyristor is in a conducting state; and an energizing circuit having a predetermined voltage threshold of conduction, said energizing circuit being connected to said gate electrode.
Claim 3
Dependent Claim
29 words
A device as defined in claim 1, wherein said means for providing a biasing electrical potential includes one or more diodes connected in series to define a diode string.
Claim 4
Dependent Claim
23 words
A device as defined in claim 2, wherein said energizing circuit is a series circuit including a resistance and a normally nonconductive element.
Claim 5
Independent Claim
80 words
A device for protecting electrical circuitry against voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a silicon controlled rectifier having anode, cathode and gate electrodes, and a plurality of diodes connected in series with the anode to cathode junction of said controlled rectifier; and a series circuit including a resistance and a unidirectional breakdown diode, said series circuit being connected to said gate electrode of said controlled rectifier.
Claim 6
Independent Claim
80 words
A device for protecting electrical circuitry against voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a silicon controlled rectifier having anode, cathode and gate electrodes, and a plurality of diodes connected in series with the anode to cathode junction of said controlled rectifier; and a series circuit including a resistance and a unidirectional breakdown diode, said series circuit being connected to said gate electrode of said controlled rectifier.
Claim 7
Dependent Claim
59 words
A device as defined in claim 4, wherein: said series circuit has a predetermined threshold voltage of conduction, said silicon controlled rectifier being triggered when said series circuit conducts; and the sum of the values of the forward voltage drops across said plurality of diodes and said silicon controlled rectifier is substantially equal to or below said threshold voltage.
Claim 8
Dependent Claim
13 words
A device as defined in claim 4, wherein said resistance is selectively variable.
Claim 9
Independent Claim
79 words
A device for protecting electrical circuitry from voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a plurality of diodes and a silicon controlled rectifier connected in series, said silicon controlled rectifier having a gate electrode; and a series circuit including a Zener diode and a resistance, said series circuit being connected to said gate electrode, said series circuit being further connected to a remote transient sense terminal.
Claim 10
Independent Claim
79 words
A device for protecting electrical circuitry from voltage transients, said device comprising: means for clamping the voltage across two terminals to a characteristic voltage when energized, including a plurality of diodes and a silicon controlled rectifier connected in series, said silicon controlled rectifier having a gate electrode; and a series circuit including a Zener diode and a resistance, said series circuit being connected to said gate electrode, said series circuit being further connected to a remote transient sense terminal.
Claim 11
Dependent Claim
22 words
A device as defined in claim 4, and further including capacitive enhancement means for aiding in turning on said silicon controlled rectifier.
Claim 12
Dependent Claim
20 words
A device as defined in claim 8, wherein said enhancement means includes a capacitor connected across said plurality of diodes.
Claim 13
Dependent Claim
26 words
A device as defined in claim 8, wherein said enhancement means includes a capacitor connected in parallel with at least one of said plurality of diodes.
Claim 14
Dependent Claim
30 words
A device as defined in claim 8, wherein said enhancement means includes a capacitor and a parallel resistor connected in parallel with at least one of said plurality of diodes.
Claim 15
Dependent Claim
24 words
A device as defined in claim 4 and further including stabilizing means for stabilizing the short rise-time transient response of said silicon controlled rectifier.
Claim 16
Dependent Claim
26 words
A device as defined in claim 12, wherein said stabilizing means includes a capacitor connected across the anode to cathode junction of said silicon controlled rectifier.
Claim 17
Dependent Claim
37 words
A device as defined in claim 4, and further including: a first capacitor connected in parallel across said plurality of diodes; and a second capacitor connected across the anode to cathode junction of said silicon controlled rectifier.
Claim 18
Dependent Claim
41 words
A device as defined in claim 4 and further including: a first capacitor connected in parallel with at least one of said plurality of diodes; and a second capacitor connected across the anode to cathode junction of said silicon controlled rectifier.
Claim 19
Independent Claim
53 words
A device for protecting electrical circuitry from voltage transients, said device comprising: at least one bidirectional breakdown diode connected in series with a bidirectional triode thyristor, said thYristor having a gate electrode; and a series circuit including a resistance and a bidirectional breakdown diode, said series circuit being connected to said gate electrode.
Claim 20
Independent Claim
53 words
A device for protecting electrical circuitry from voltage transients, said device comprising: at least one bidirectional breakdown diode connected in series with a bidirectional triode thyristor, said thYristor having a gate electrode; and a series circuit including a resistance and a bidirectional breakdown diode, said series circuit being connected to said gate electrode.
Claim 21
Independent Claim
115 words
A device for protecting electrical circuitry from voltage transients, said device comprising: a full-wave rectifying bridge; a plurality of diodes and a silicon controlled rectifier connected in series across the output terminals of said full-wave bridge, the sum of the forward voltage drops across said diodes and said silicon controlled rectifier being a predetermined clamp voltage level, said silicon controlled rectifier having a gate electrode; and a series circuit including a Zener diode and a resistance connected to said gate electrode with said Zener diode being back biased and the threshold voltage at which said Zener diode conducts to trigger said silicon controlled rectifier into conduction being substantially equal to or above said clamp voltage.
Claim 22
Independent Claim
115 words
A device for protecting electrical circuitry from voltage transients, said device comprising: a full-wave rectifying bridge; a plurality of diodes and a silicon controlled rectifier connected in series across the output terminals of said full-wave bridge, the sum of the forward voltage drops across said diodes and said silicon controlled rectifier being a predetermined clamp voltage level, said silicon controlled rectifier having a gate electrode; and a series circuit including a Zener diode and a resistance connected to said gate electrode with said Zener diode being back biased and the threshold voltage at which said Zener diode conducts to trigger said silicon controlled rectifier into conduction being substantially equal to or above said clamp 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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |