US3600634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective control circuit against transient voltages
Assignee: Wind River Systems Inc
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Filing: 1969-12-16
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Granted: 1971-08-17
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Expires: 1989-12-16
Abstract
Abstract A load protective circuit using a pair of solid state gate controlled AC switches, each connected from one side of a transmission line to ground in order to shunt the load terminals of the load from overvoltages. In the first embodiment, a firing control resistor connected between the gate terminal of the triac and ground determines the firing voltage to be presented to the gate terminal when a transient occurs on the transmission line and thereby renders the triac conductive if the firing voltage exceeds the triac threshold voltage. In the second embodiment, the firing control resistor is a variable potentiometer by which the firing voltage applied to the gate terminal of the triacs may be varied to vary the overall protection firing voltage.
Inventors
- 👤 Charles A Muench Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:32
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/04; H02H9/041
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
176 words
An overvoltage protective circuit having a load to be protected which is connected across a pair of transmission line leads comprising: a first solid-state gate controlled AC switch connected in shunt relation relative to the load from a first transmission line lead to ground, a second solid-state gate controlled AC switch connected in shunt relation relative to the load from a second transmission line lead to ground, each switch having a first power terminal connected to the respective transmission line and a second power terminal connected to ground, each switch further having a firing control circuit connected from the gate to the second power terminal for determining times at which the switch will be rendered conductive based upon the magnitude of the overvoltage on the transmission line appearing across the power terminals of the switch, whereby when an overvoltage is present on at least one of the transmission lines the firing control circuit of the respective switch senses the overvoltage and renders the respective switch conductive upon the predetermined firing voltage of the switch being exceeded.
Claim 2
Dependent Claim
176 words
An overvoltage protective circuit having a load to be protected which is connected across a pair of transmission line leads comprising: a first solid-state gate controlled AC switch connected in shunt relation relative to the load from a first transmission line lead to ground, a second solid-state gate controlled AC switch connected in shunt relation relative to the load from a second transmission line lead to ground, each switch having a first power terminal connected to the respective transmission line and a second power terminal connected to ground, each switch further having a firing control circuit connected from the gate to the second power terminal for determining times at which the switch will be rendered conductive based upon the magnitude of the overvoltage on the transmission line appearing across the power terminals of the switch, whereby when an overvoltage is present on at least one of the transmission lines the firing control circuit of the respective switch senses the overvoltage and renders the respective switch conductive upon the predetermined firing voltage of the switch being exceeded.
Claim 3
Dependent Claim
27 words
The overvoltage protective circuit of claim 1 wherein the firing control circuit comprises a sensing element to sense the presence of an overvoltage on the transmission line.
Claim 4
Dependent Claim
61 words
The overvoltage protective circuit of claim 2 wherein the sensing element upon sensing an overvoltage is adapted to cause a biasing control signal to be applied to the gate of the switch, the value of the biasing control signal relative to the magnitude of the overvoltage to thereby render the switch conductive upon the firing voltage of the switch being exceeded.
Claim 5
Dependent Claim
14 words
The overvoltage protective circuit of claim 3 wherein the sensing element is a resistance.
Claim 6
Dependent Claim
15 words
The overvoltage protective circuit of claim 3 wherein the sensing element is a variable resistance.
Claim 7
Dependent Claim
147 words
An overvoltage protective circuit having a load to be protected which is connected across at least one transmission line lead and ground comprising a solid-state gate conTrolled AC switch connected in shunt relation relative to the load from the transmission line lead to ground, the switch having a first power terminal connected to the respective transmission line and a second power terminal connected to ground, the switch further having a firing control circuit connected from the gate to the second power terminal for determining times at which the switch will be rendered conductive based upon the magnitude of the overvoltage on the transmission line appearing across the power terminals of the switch, whereby when an overvoltage is present on the transmission line the firing control circuit of the switch senses the overvoltage and renders the switch conductive upon the predetermined firing voltage of the switch being exceeded.
Claim 8
Dependent Claim
147 words
An overvoltage protective circuit having a load to be protected which is connected across at least one transmission line lead and ground comprising a solid-state gate conTrolled AC switch connected in shunt relation relative to the load from the transmission line lead to ground, the switch having a first power terminal connected to the respective transmission line and a second power terminal connected to ground, the switch further having a firing control circuit connected from the gate to the second power terminal for determining times at which the switch will be rendered conductive based upon the magnitude of the overvoltage on the transmission line appearing across the power terminals of the switch, whereby when an overvoltage is present on the transmission line the firing control circuit of the switch senses the overvoltage and renders the switch conductive upon the predetermined firing voltage of the switch being exceeded.
Claim 9
Dependent Claim
27 words
The overvoltage protective circuit of claim 6 wherein the firing control circuit comprises a sensing element to sense the presence of an overvoltage on the transmission line.
Claim 10
Dependent Claim
62 words
The overvoltage protective circuit of claim 7 wherein the sensing element upon sensing an overvoltage is adapted to cause a biasing control signal to be applied to the gate of the switch, the value of the biasing control signal being relative to the magnitude of the overvoltage to thereby render the switch conductive upon the firing voltage of the switch being exceeded.
Claim 11
Dependent Claim
14 words
The overvoltage protective circuit of claim 8 wherein the sensing element is a resistance.
Claim 12
Dependent Claim
15 words
The overvoltage protective circuit of claim 8 wherein the sensing element is a variable resistance.
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) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |