US3697782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-state zero-crossing detector
Assignee: Motors Liquidation Co
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Filing: 1971-09-20
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Granted: 1972-10-10
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Expires: 1991-09-20
Abstract
Abstract A comparator having two output states and two input connections is used to develop an indication of the polarity of an alternating voltage. The comparator output is coupled with one of two inputs of the comparator. Two voltage controlled switches including opposite conductivity type transistors and oppositely poled diodes are connected such that the voltage being sensed is applied to the second input to the comparator when it changes polarity, thereby changing the state of the comparator output. Control of the switches in accordance with the comparator output and the sensed voltage provides a disconnect feature whereby the detector draws power from the sensed voltage only during switching intervals; no power is drawn after a change in polarity by the sensed voltage until it again reverses its polarity.
Inventors
- 👤 Michael F Matouka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:32
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/08; H03K5/153; H03K5/1536
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polaRity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second voltage controlled switches, each of said switches being coupled with the output of said comparator and adapted to be connected with the voltage being sensed, each of said switches being responsive to the polarities of both the comparator output voltage and the sensed voltage, and each of said switches being conductive only on the occasion of a respective predetermined combination of the two voltage polarities connected with it; and means for coupling both of said switches with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, one of said switches conducts applying voltage to the second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
Claim 2
Dependent Claim
181 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polaRity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second voltage controlled switches, each of said switches being coupled with the output of said comparator and adapted to be connected with the voltage being sensed, each of said switches being responsive to the polarities of both the comparator output voltage and the sensed voltage, and each of said switches being conductive only on the occasion of a respective predetermined combination of the two voltage polarities connected with it; and means for coupling both of said switches with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, one of said switches conducts applying voltage to the second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
Claim 3
Dependent Claim
184 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polarity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second voltage controlled switches, each of said switches including a transistor coupled with and controlled by the output of said comparator and a diode adapted to be connected with the voltage being sensed, said switches having transistors of opposite conductivity types and diodes poled such that each of said switches is conductive only on the occasion of a respective predetermined combination of the two voltage polarities connected with its diode and transistor; and means for coupling both of said switches with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, one of said switches conducts applying voltage to the second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
Claim 4
Dependent Claim
184 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polarity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second voltage controlled switches, each of said switches including a transistor coupled with and controlled by the output of said comparator and a diode adapted to be connected with the voltage being sensed, said switches having transistors of opposite conductivity types and diodes poled such that each of said switches is conductive only on the occasion of a respective predetermined combination of the two voltage polarities connected with its diode and transistor; and means for coupling both of said switches with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, one of said switches conducts applying voltage to the second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
Claim 5
Dependent Claim
214 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polarity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second transistors of opposite conductivity types, each of said transistors having its base-emitter control circuit coupled with said comparator output such that conduction from collector to emitter for each transistor is controlled in accordance with the output of said comparator, one of said transistors being biased conductive in its collector-emitter circuit and the other nonconductive for each output polarity of said comparator; first and second diodes adapted for interconnecting said transistors with the voltage to be sensed, said diodes being poled such that one is forward biased and the other reverse biased for each input polarity; and means for coupling both of said transistors with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, the sensed voltage is connected through a respective diode and a respective transistor with said second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
Claim 6
Dependent Claim
214 words
A circuit for sensing voltage polarity changes and providing an indication thereof, comprising: a voltage comparator having first and second inputs and providing an output having a polarity determined by the relative polarity of the voltages connected at the inputs of said comparator; means coupling said output with said first input; first and second transistors of opposite conductivity types, each of said transistors having its base-emitter control circuit coupled with said comparator output such that conduction from collector to emitter for each transistor is controlled in accordance with the output of said comparator, one of said transistors being biased conductive in its collector-emitter circuit and the other nonconductive for each output polarity of said comparator; first and second diodes adapted for interconnecting said transistors with the voltage to be sensed, said diodes being poled such that one is forward biased and the other reverse biased for each input polarity; and means for coupling both of said transistors with said second input of said comparator such that on the occasion of each change in polarity by the voltage being sensed, the sensed voltage is connected through a respective diode and a respective transistor with said second input of said comparator reversing the polarity of the comparator output indicating a reversal of the sensed voltage polarity.
References Cited (Backward Citations)
US3509372A
Cited
US3571621A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |