US3718839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Under-voltage protection device
Assignee: Individual
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Filing: 1971-07-30
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Granted: 1973-02-27
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Expires: 1991-07-30
Abstract
Abstract An under-voltage protection device including an A.C. source connected across a load; a series combination of a line switch and a control rectifier connected between the A.C. source and the load; and a series combination of a rectifier and voltage divider connected across the A.C. source; wherein the control electrode of the control rectifier is connected to an adjustable terminal of the voltage divider.
Inventors
- 👤 D Conti
- 👤 T Reilly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:35
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
An under-voltage protection dEvice, comprising: an A.C. voltage source having first and second terminals connected across a load; switching means connected in series with said source and said load for making and breaking an electrical connection therebetween; means rectifying said A.C. voltage; means filtering said rectified A.C. voltage; voltage dividing means connected to the output of said filter means; means actuated by a current passing therethrough for controlling said switching means; a control rectifier having an anode, a cathode and a control electrode; a series combination of said switch control means and said control rectifier connected between the output of said rectifying means and said A.C. voltage source; wherein said control electrode is connected to an adjustable terminal of said voltage divider.
Claim 2
Dependent Claim
122 words
An under-voltage protection dEvice, comprising: an A.C. voltage source having first and second terminals connected across a load; switching means connected in series with said source and said load for making and breaking an electrical connection therebetween; means rectifying said A.C. voltage; means filtering said rectified A.C. voltage; voltage dividing means connected to the output of said filter means; means actuated by a current passing therethrough for controlling said switching means; a control rectifier having an anode, a cathode and a control electrode; a series combination of said switch control means and said control rectifier connected between the output of said rectifying means and said A.C. voltage source; wherein said control electrode is connected to an adjustable terminal of said voltage divider.
Claim 3
Dependent Claim
71 words
An under-voltage protection device according to claim 1, wherein the input of said rectifying means is connected to said first terminal; said filtering means is connected between the output of said rectifying means and said second terminal; said voltage dividing means is connected between the output of said filtering means and said second terminal; and said series combination is connected between the output of said rectifying means and said second terminal.
Claim 4
Dependent Claim
42 words
An under-voltage protection device according to claim 1, wherein said series combination further comprises a resistance connected between said cathode and said A.C. source, said anode being connected to said A.C. voltage source through said switch control means and said rectifying means.
Claim 5
Dependent Claim
133 words
An under-voltage protection device according to claim 1, wherein said rectifying means comprises a diode, the anode of said diode being connected to said first terminal of said A.C. voltage source; said filtering means comprises a series combination of a resistor and capacitor connected between the cathode of said diode and said second terminal of said A.C. voltage source; said voltage divider is connected in parallel with said capacitor; said switch control means comprises a relay coil; a first terminal of said relay coil is connected to the cathode of said diode, a second terminal of said relay coil is connected in series with a resistor to the anode of said control rectifier and the cathode of said control rectifier is connected through a resistor to said second terminal of said A.C. source.
Claim 6
Dependent Claim
23 words
An under-voltage protection device according to claim 4, further comprising a capacitor connected across the series combination of said relay coil and resistance.
Claim 7
Dependent Claim
121 words
An under-voltage protection device, comprising: an A.C. voltage source having first and second terminals connected across a load; switching means connected in series with said source and said load for making and breaking an electrical connection therebetween; means rectifying said A.C. voltage; means filtering said rectified A.C. voltage; voltage dividing means connected to the output of said filter means; means actuated by a current passing therethrough for controlling said switching means; a control rectifier having an anode, a cathode and a control electrode; a series combination of said switch control means and said control rectifier connected between said first and second terminals of said A.C. voltage source; wherein said control electrode is connected to an adjustable terminal of said voltage divider.
Claim 8
Dependent Claim
121 words
An under-voltage protection device, comprising: an A.C. voltage source having first and second terminals connected across a load; switching means connected in series with said source and said load for making and breaking an electrical connection therebetween; means rectifying said A.C. voltage; means filtering said rectified A.C. voltage; voltage dividing means connected to the output of said filter means; means actuated by a current passing therethrough for controlling said switching means; a control rectifier having an anode, a cathode and a control electrode; a series combination of said switch control means and said control rectifier connected between said first and second terminals of said A.C. voltage source; wherein said control electrode is connected to an adjustable terminal of said voltage divider.
Claim 9
Dependent Claim
38 words
An under-voltage protection device according to claim 6, wherein said switching means comprises a bi-metallic element; and further comprising means for heating said bi-metallic element to make and break said electrical connection between said source and said load.
Claim 10
Dependent Claim
24 words
An under-voltage protection device according to claim 7, wherein said heating means comprises a first resistance connected between said anode and said A.C. source.
Claim 11
Dependent Claim
33 words
An under-voltage protection device according to claim 8, further comprising a second resistance connected in series with said first resistance; said bi-metallic element having at least one contact connected tO said second resistance.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |