US3769550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage sensitive control device
Assignee: Lear Siegler Inc
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Filing: 1972-05-30
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Granted: 1973-10-30
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Expires: 1992-05-30
Abstract
Abstract A power supply monitor circuit which disconnects a load from the alternating current supply lines when the output voltage from the supply drops below a predetermined level for an interval of time exceeding a certain predetermined tolerable interval. The output voltage level of the supply is sensed by a voltage divider connected in parallel with the supply, and a Zener diode is used to establish a lower threshold at which a silicon controlled rectifier (SCR) can be fired. The SCR is connected in series with a load cut-out relay to thereby control the relay energization. A time delay circuit is associated with the gate electrode of the SCR to allow conduction thereof for a short time period following a drop in supply voltage, thus establishing the tolerable interval and permitting and accommodating momentary voltage drops.
Inventors
- 👤 I Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:12
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/24; H02H3/247
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
294 words
A power supply monitoring circuit for disconnecting a load device from a power supply in the event of a sustained drop in supply voltage, said circuit including: a. first and second lines adapted to be connected to a source of alternating current; b. a relay having a coil and a set of normally open contacts associated therewith; c. a first triggerable switching means having a pair of output electrodes and a control electrode; d. a second triggerable switching means having a pair of ouTput electrodes and a control electrode; e. means connecting said relay coil and the output electrodes of said first and second triggerable switching means in series between said first and second lines; f. a resistive voltage divider connected in parallel with the series combination of said first and second triggerable switching means and said relay coil; g. means including a voltage threshold establishing device connecting said voltage divider to the control electrode of said first triggerable switching means, such that said relay coil is maintained energized and said contacts are maintained closed so long as the voltage applied to said first control electrode exceeds said threshold; h. delay means connected to said first control electrode for maintaining a triggering signal thereon for at least a first predetermined time period following said drop in supply voltage, said delay means connected to said first control electrode including a resistor and a capacitor connected in parallel with each other and in series with said voltage threshold establishing device; i. timing means associated with the electrode of said second triggerable switching means, said timingmeans being operative upon triggering of said first triggerable switching means to apply triggering signals to said second control electrode a predetermined time following the triggering of said first triggerable switching means.
Claim 2
Dependent Claim
294 words
A power supply monitoring circuit for disconnecting a load device from a power supply in the event of a sustained drop in supply voltage, said circuit including: a. first and second lines adapted to be connected to a source of alternating current; b. a relay having a coil and a set of normally open contacts associated therewith; c. a first triggerable switching means having a pair of output electrodes and a control electrode; d. a second triggerable switching means having a pair of ouTput electrodes and a control electrode; e. means connecting said relay coil and the output electrodes of said first and second triggerable switching means in series between said first and second lines; f. a resistive voltage divider connected in parallel with the series combination of said first and second triggerable switching means and said relay coil; g. means including a voltage threshold establishing device connecting said voltage divider to the control electrode of said first triggerable switching means, such that said relay coil is maintained energized and said contacts are maintained closed so long as the voltage applied to said first control electrode exceeds said threshold; h. delay means connected to said first control electrode for maintaining a triggering signal thereon for at least a first predetermined time period following said drop in supply voltage, said delay means connected to said first control electrode including a resistor and a capacitor connected in parallel with each other and in series with said voltage threshold establishing device; i. timing means associated with the electrode of said second triggerable switching means, said timingmeans being operative upon triggering of said first triggerable switching means to apply triggering signals to said second control electrode a predetermined time following the triggering of said first triggerable switching means.
Claim 3
Dependent Claim
54 words
a uni-junction transistor having a pair of output electrodes and a control electrode, the control electrode of said uni-junction transistor being connected to the common point between said resistor and capacitor, and the pair of output electrodes of said uni-junction said transistor being coupled to the control electrode of said second triggerable switching means.
Claim 4
Dependent Claim
54 words
a uni-junction transistor having a pair of output electrodes and a control electrode, the control electrode of said uni-junction transistor being connected to the common point between said resistor and capacitor, and the pair of output electrodes of said uni-junction said transistor being coupled to the control electrode of said second triggerable switching means.
Claim 5
Dependent Claim
300 words
A power supply monitoring circuit for disconnecting a load device from a power supply in the event of a sustained drop in supply voltage, said circuit including: a. first and second lines adapted to be connected to a source of alternating current; b. a relay having a coil and a set of normally open contacts associated therewith; c. a first triggerable switching means having pair of output electrodes and a control electrode; d. a second triggerable switching means having a pair of output electrodes and a control electrode; e. means connecting said relay coil and the output electrodes of said first and second triggerable switching means in series between said first and second lines; f. a resistive voltage divider connected in parallel with the series combination of said first and second triggerable switching means and said relay coil; g. means including a voltage threshold establishing device connecting said voltage divider to the control electrode of said first triggerable switching means, such that said relay coil is maintained energized and said contacts are maintained closed so long as the voltage applied to said first control electrode exceeds said threshold; h. delay means connected to said first control electrode for maintaining a triggering signal thereon for at least a first predetermined time period following said drop in supply voltage, said delay means connected to said first control electrode including a resistor and a capacitor connected in parallel with each other and in series with said voltage threshold establishing device; i. timing means associated with the control electrode of said second triggerable switching means, said timing means being operative upon triggering of said first triggerable switching means to apply triggering signals to said second control electrode a predetermined time following the triggering of said first triggerable switching means; j. said timing means including:
Claim 6
Dependent Claim
300 words
A power supply monitoring circuit for disconnecting a load device from a power supply in the event of a sustained drop in supply voltage, said circuit including: a. first and second lines adapted to be connected to a source of alternating current; b. a relay having a coil and a set of normally open contacts associated therewith; c. a first triggerable switching means having pair of output electrodes and a control electrode; d. a second triggerable switching means having a pair of output electrodes and a control electrode; e. means connecting said relay coil and the output electrodes of said first and second triggerable switching means in series between said first and second lines; f. a resistive voltage divider connected in parallel with the series combination of said first and second triggerable switching means and said relay coil; g. means including a voltage threshold establishing device connecting said voltage divider to the control electrode of said first triggerable switching means, such that said relay coil is maintained energized and said contacts are maintained closed so long as the voltage applied to said first control electrode exceeds said threshold; h. delay means connected to said first control electrode for maintaining a triggering signal thereon for at least a first predetermined time period following said drop in supply voltage, said delay means connected to said first control electrode including a resistor and a capacitor connected in parallel with each other and in series with said voltage threshold establishing device; i. timing means associated with the control electrode of said second triggerable switching means, said timing means being operative upon triggering of said first triggerable switching means to apply triggering signals to said second control electrode a predetermined time following the triggering of said first triggerable switching means; j. said timing means including:
References Cited (Backward Citations)
FR1360312A
Cited
US3243796A
Cited
US3335325A
Cited
US3434011A
Cited
US3566198A
Cited
US3611050A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |