Patent US3733498A successfully refreshed from Google Patents.
US3733498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual-voltage feedback comparator for simultaneously monitoring a positive and negative voltage
Assignee: Telex Computer Products Inc
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Filing: 1971-09-27
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Granted: 1973-05-15
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Expires: 1991-09-27
Abstract
Abstract In this invention a positive voltage V1 and a negative voltage V2 are simultaneously monitored by two voltage comparators, which compare voltages on two potentiometers with a standard reference voltage. The potentiometers are tied between constant current loops, each comprising a zener diode, a resistance, and a transistor. When either of the voltages changes the collector of the appropriate transistor takes up the voltage, and thus the potentiometers shift in their potential in accordance with the change of the monitored voltages. These changes in potential are transferred to the comparators which switch their output from a logical zero to a logical one whenever the voltages they are monitoring vary by more than a selected value from a preselected value.
Inventors
- 👤 M Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:01
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16566; G01R19/16576
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
160 words
A dual-voltage feedback comparator comprising: a. a first terminal connected to a positive voltage and a second terminal connected to a negative voltage; b. a first constant current circuit connected between said first and said second terminals comprising in series, a first zener diode, a first potentiometer, the collector of an NPN transistor, the emitter of which is connected through a first resistor to said second terminal; c. a second constant current circuit connected between said first and second terminals comprising, in series, a second resistor, the emitter of a PNP transistor, the collector of which is connected to a second potentiometer, and a second zener diode; d. the base of a said NPN transistor connected to the junction between said second potentiometer and said second diode, and the base of said PNP transistor connected to the junction between said first diode and said first potentiometer; and e. means to compare the voltages of said potentiometers to a reference voltage.
Claim 2
Dependent Claim
160 words
A dual-voltage feedback comparator comprising: a. a first terminal connected to a positive voltage and a second terminal connected to a negative voltage; b. a first constant current circuit connected between said first and said second terminals comprising in series, a first zener diode, a first potentiometer, the collector of an NPN transistor, the emitter of which is connected through a first resistor to said second terminal; c. a second constant current circuit connected between said first and second terminals comprising, in series, a second resistor, the emitter of a PNP transistor, the collector of which is connected to a second potentiometer, and a second zener diode; d. the base of a said NPN transistor connected to the junction between said second potentiometer and said second diode, and the base of said PNP transistor connected to the junction between said first diode and said first potentiometer; and e. means to compare the voltages of said potentiometers to a reference voltage.
Claim 3
Dependent Claim
62 words
The comparator as in claim 1 in which said means to compare comprises: a. a first voltage comparator with its negative input terminal connected to said first potentiometer and its positive potential connected to said reference voltage; and b. a second voltage comparator with its positive input terminal connected to said second potentiometer, and its negative terminal connected to said reference voltage.
Claim 4
Dependent Claim
23 words
The comparator as in claim 2 in which the lead from said first comparator is connected to the slider of said first potentiometer.
Claim 5
Dependent Claim
23 words
The comparator as in claim 2 in which the lead from said second comparator is connected to the slider of said second potentiometer.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |