Patent US3750146A successfully refreshed from Google Patents.
US3750146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitively coupled reference signal and associated circuitry particularly for analog to digital, digital to analog converters and the like
Assignee: Gordon Engineering Co
•
Filing: 1971-12-13
•
Granted: 1973-07-31
•
Expires: 1991-12-13
Abstract
Abstract A reference source is AC coupled to a converter for selectively providing both positive and negative reference signals to the converter. A reference signal potential is selectively applied to a first side of a first capacitor via a sequence of switches and a second side of the first capacitor is selectively connected to a common signal through a return switch. A first signal is presented at the second side of the first capacitor when a first switch of the sequence of switches and the return switch are closed. A second signal is presented at the second side of the first capacitor when the first and return switches are opened and a second switch of the sequence of switches is closed. The second signal presented at the second side of the first is the reference signal having a given polarity with respect to the common signal. Automatic zeroing of an offset voltage generated by an integrator and a comparator of the analog to digital converter is provided by a second capacitor serially connected between an input terminal of the integrator and the common signal, the integrator and comparator being connected in a closed loop configuration. A voltage ratio measurement by the analog to digital converter, the ratio of the voltage across a first resistor having a known resistance to the voltage across a second resistor having an unknown resistance, represents the resistance value of the second resistor.
Inventors
- 👤 P Lucas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:50
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/50; H03M1/52
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
206 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. capacitor means having first and second terminal means; b. first switch means having first and second switching states, said first switch means operatively connected to said first terminal means for selectively and independently applying at least first and second signals to said first terminal means; and c. second switch means having opened and closed switching states, said second switch means operatively connected to said second terminal means for selectively applying a return signal to said second terminal means; d. said first signal applied to said first terminal means and coupled to said second terminal means through said capacitor means when said first switch means is in said first switching state and said second switch means is in said closed switching state, said second signal applied to said first terminal means when said first switch means is in said second switching state and said second switch means is in said opened state, a reference signal presented at said second terminal means when said second signal is applied to said first terminal means, said reference signal being the difference between said first and second signals with respect to said return signal.
Claim 2
Independent Claim
206 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. capacitor means having first and second terminal means; b. first switch means having first and second switching states, said first switch means operatively connected to said first terminal means for selectively and independently applying at least first and second signals to said first terminal means; and c. second switch means having opened and closed switching states, said second switch means operatively connected to said second terminal means for selectively applying a return signal to said second terminal means; d. said first signal applied to said first terminal means and coupled to said second terminal means through said capacitor means when said first switch means is in said first switching state and said second switch means is in said closed switching state, said second signal applied to said first terminal means when said first switch means is in said second switching state and said second switch means is in said opened state, a reference signal presented at said second terminal means when said second signal is applied to said first terminal means, said reference signal being the difference between said first and second signals with respect to said return signal.
Claim 3
Independent Claim
231 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. first switch means having first and second terminal means, said first terminal means adapted for reception of a first signal; b. second switch means having third and fourth terminal means, said third terminal means adapted for reception of a second signal, said second and fourth terminal means connected at a first junction; c. capacitor means having fifth and sixth terminal means, said fifth terminal means connected to said first junction; and d. third switch means having seventh and eighth terminal means, said sixth and seventh terminal means connected at a second junction, said eighth terminal means adapted for reception of a return signal; e. said first signal applied to said first junction and coupled to said second junction through said capacitor means when said first and third switch means are closed and said second switch means is opened, said return signal applied to said second junction when said third switch means is closed; f. said second signal applied to said first junction when said first and third switch means are opened and said second switch means is closed, a reference signal presented at said second junction when said second signal is applied to said first junction, said reference signal being the difference between said first and second signals with respect to said return signal.
Claim 4
Independent Claim
231 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. first switch means having first and second terminal means, said first terminal means adapted for reception of a first signal; b. second switch means having third and fourth terminal means, said third terminal means adapted for reception of a second signal, said second and fourth terminal means connected at a first junction; c. capacitor means having fifth and sixth terminal means, said fifth terminal means connected to said first junction; and d. third switch means having seventh and eighth terminal means, said sixth and seventh terminal means connected at a second junction, said eighth terminal means adapted for reception of a return signal; e. said first signal applied to said first junction and coupled to said second junction through said capacitor means when said first and third switch means are closed and said second switch means is opened, said return signal applied to said second junction when said third switch means is closed; f. said second signal applied to said first junction when said first and third switch means are opened and said second switch means is closed, a reference signal presented at said second junction when said second signal is applied to said first junction, said reference signal being the difference between said first and second signals with respect to said return signal.
Claim 5
Independent Claim
284 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. first switch means having first and second terminal means, said first terminal means adapted for reception of a first signal; b. second switch means having third and fourth terminal means, said third terminal means adapted for reception of a second signal; c. third switch means having fifth and sixth terminal means, said fifth terminal means adapted for reception of a third signal; d. said second, fourth and sixth terminal means connected at a first junction; e. capacitor means having seventh and eighth terminal means, said seventh terminal means connected to said first junction; f. fourth switch means having ninth and tenth terminal means, said eighth and ninth terminal means connected at a second junction, said tenth terminal means adapted for reception of a return signal; g. said second signal applied to said first junction and coupled to said second junction through said capacitor means when said second and fourth switch means are closed and said first and third switch means are opened, said return signal applied to said second junction when said fourth switch means is closed; h. a first reference signal presented at said second junction when said second and fourth switch means are opened and said first switch means is closed and a second reference signal presented at said second junction when said second and fourth switch means are opened and said third switch means is closed, said first reference signal being the difference between said first and second signals with respect to said return signal, said second reference signal being the difference between said second and third signals with respect to said return signal.
Claim 6
Independent Claim
284 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. first switch means having first and second terminal means, said first terminal means adapted for reception of a first signal; b. second switch means having third and fourth terminal means, said third terminal means adapted for reception of a second signal; c. third switch means having fifth and sixth terminal means, said fifth terminal means adapted for reception of a third signal; d. said second, fourth and sixth terminal means connected at a first junction; e. capacitor means having seventh and eighth terminal means, said seventh terminal means connected to said first junction; f. fourth switch means having ninth and tenth terminal means, said eighth and ninth terminal means connected at a second junction, said tenth terminal means adapted for reception of a return signal; g. said second signal applied to said first junction and coupled to said second junction through said capacitor means when said second and fourth switch means are closed and said first and third switch means are opened, said return signal applied to said second junction when said fourth switch means is closed; h. a first reference signal presented at said second junction when said second and fourth switch means are opened and said first switch means is closed and a second reference signal presented at said second junction when said second and fourth switch means are opened and said third switch means is closed, said first reference signal being the difference between said first and second signals with respect to said return signal, said second reference signal being the difference between said second and third signals with respect to said return signal.
Claim 7
Independent Claim
129 words
A device for presenting an analog signal in digital form, said device comprising: a. first and second terminal means adapted for reception of an analog signal; b. converter means having third, fourth, fifth and sixth terminal means, said third and fourth terminal means defining first input terminal means, said fifth and sixth terminal means defining first output terminal means, said first and third terminal means connected at a first junction, said second and fourth terminal means connected at a second junction adapted for interconnection with a return signal; and c. AC coupled reference source means operatively connected to said first junction for selectively applying a reference signal thereto; d. said analog signal at said first input terminal means being presEnted at said first output terminal means in digital form.
Claim 8
Independent Claim
129 words
A device for presenting an analog signal in digital form, said device comprising: a. first and second terminal means adapted for reception of an analog signal; b. converter means having third, fourth, fifth and sixth terminal means, said third and fourth terminal means defining first input terminal means, said fifth and sixth terminal means defining first output terminal means, said first and third terminal means connected at a first junction, said second and fourth terminal means connected at a second junction adapted for interconnection with a return signal; and c. AC coupled reference source means operatively connected to said first junction for selectively applying a reference signal thereto; d. said analog signal at said first input terminal means being presEnted at said first output terminal means in digital form.
Claim 9
Dependent Claim
212 words
The device as claimed in claim 4 wherein said reference source includes: a. first capacitor means having seventh and eighth terminal means, said eighth terminal means connected to said first junction; b. first switch means having first and second switching states, said first switch means operatively connected to said seventh terminal means for selectively and independently applying at least first and second signals to said seventh terminal means; and c. second switch means having opened and closed switching states, said second switch means operatively connected between said first and second junctions for selectively applying said return signal to said eighth terminal means; d. said first signal applied to said seventh terminal means and coupled to said first junction through said first capacitor means when said first switch means is in said first switching state and said second switch means is in said closing switching state, said second signal applied to said seventh terminal means when said first switch means is in said second switching state and said second switch means is in said opened state, a reference signal presented at said first junction when said second signal is applied to said seventh terminal means, said reference signal being the difference between said first and second signals with respect to said return signal.
Claim 10
Dependent Claim
286 words
The device as claimed in claim 5 wherein said converter means is closed loop converter means including: a. integrator means having ninth, tenth and eleventh terminal means, said ninth and tenth terminal means defining second input terminal means, said eleventh terminal means defining second output terminal means, said tenth terminal means operatively connected to said first junction; b. comparator means having twelfth, thirteenth and fourteenth terminal means said twelfth and thirteenth terminal means defining third input terminal means, said fourteenth terminal means defining third output terminal means, said twelfth terminal means operatively connected to said eleventh terminal means, said twelfth terminal means operatively connected to said return signal; c. second capacitor means having fifteenth and sixteenth terminal means, said fifteenth terminal means operatively connected to said tenth terminal means, said sixteenth terminal means connected to said return signal; and d. third switch means having third and fourth switching states, said third switch means serially connected between said fourteen and fifteenth terminal means for selectively applying an offset signal of said integrator means and comparator means as at said fourteenth terminal means to said second capacitor means when said third switch means is in said third switching state, said second capacitor means storing said offset signal when said third switch means is in said third switching state, said second capacitor means being disconnected from said fourteenth terminal means when said third switch means is in said fourth switching state, said offset signal stored on said capacitor being applied to said tenth terminal means when said third switch means is in said fourth switching state, said stored offset signal applied to said tenth terminal means operating to compensate for said offset signal of said integrator and comparator means.
Claim 11
Dependent Claim
50 words
The device as claimed in claim 6 including sampling means operatively connected to said fourteenth terminal means and said first and second switch means for selectively controlling the switching states of said first and second switch means as a function of a signal presented at said third output terminal means.
Claim 12
Independent Claim
170 words
A device for providing positive and negative reference signals, said device comprising: a. first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectivelY presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means, said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means; b. output terminal means; c. second means AC coupling said third terminal means and said output terminal means, a positive reference signal presented at said output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said output terminal means when said first means is operated in said second sequence.
Claim 13
Independent Claim
170 words
A device for providing positive and negative reference signals, said device comprising: a. first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectivelY presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means, said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means; b. output terminal means; c. second means AC coupling said third terminal means and said output terminal means, a positive reference signal presented at said output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said output terminal means when said first means is operated in said second sequence.
Claim 14
Dependent Claim
15 words
A device as claimed in claim 8 wherein said second means is capacitive coupling means.
Claim 15
Dependent Claim
15 words
The device as claimed in claim 8 wherein said second means is magnetic coupling means.
Claim 16
Independent Claim
151 words
A device for converting an analog signal to digital form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of an analog signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said analog signal to digital form, said reference source means having first and second states, said positive reference signal coupled to said converter means when said reference source means is in said first state and said negative reference signal coupled to said converter means when said reference source means is in said second state, said first and second states determined by said analog signal; c. said analog signal at said first input terminal means being presented at said first output terminal means in digital form.
Claim 17
Independent Claim
151 words
A device for converting an analog signal to digital form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of an analog signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said analog signal to digital form, said reference source means having first and second states, said positive reference signal coupled to said converter means when said reference source means is in said first state and said negative reference signal coupled to said converter means when said reference source means is in said second state, said first and second states determined by said analog signal; c. said analog signal at said first input terminal means being presented at said first output terminal means in digital form.
Claim 18
Independent Claim
258 words
A device for converting an analog signal to digital form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of an analog signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said analog signal to digital form, said reference source means including first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectively presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means, said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means, second output terminal means, said second means AC coupling said third terminal means and said second output terminal means, a positive reference signal presented at said second output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said second output terminal means when said first means is operated in said second sequence; c. said analog signal at said first input terminal means being presented at said first output terminal means in digital form.
Claim 19
Independent Claim
258 words
A device for converting an analog signal to digital form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of an analog signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said analog signal to digital form, said reference source means including first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectively presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means, said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means, second output terminal means, said second means AC coupling said third terminal means and said second output terminal means, a positive reference signal presented at said second output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said second output terminal means when said first means is operated in said second sequence; c. said analog signal at said first input terminal means being presented at said first output terminal means in digital form.
Claim 20
Independent Claim
149 words
A device for converting a digital signal to analog form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of a digital signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in convErting said digital signal to analog form, said reference source means having first and second states, said positive reference signal coupled to said converter means when said reference source means is in said first state and said negative reference coupled to said converter means when said reference means is in said second state, said first and second states determined by said digital signal; c. said digital signal at said first input terminal means being presented at said first output terminal means in analog form.
Claim 21
Independent Claim
149 words
A device for converting a digital signal to analog form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of a digital signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in convErting said digital signal to analog form, said reference source means having first and second states, said positive reference signal coupled to said converter means when said reference source means is in said first state and said negative reference coupled to said converter means when said reference means is in said second state, said first and second states determined by said digital signal; c. said digital signal at said first input terminal means being presented at said first output terminal means in analog form.
Claim 22
Independent Claim
258 words
A device for converting a digital signal to analog form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of a digital signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said digital signal to analog form, said reference source means including first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectively presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means, second output terminal means, and second means AC coupling said third terminal means and said second output terminal means, a positive reference signal presented at said second output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said second output terminal means when said first means is operated in said second sequence; c. said digital signal at said first input terminal means being presented at said first output terminal means in analog form.
Claim 23
Independent Claim
258 words
A device for converting a digital signal to analog form, said device comprising: a. converter means having at least first input and first output terminal means, said input terminal means adapted for reception of a digital signal; and b. reference source means AC coupled to said converter means and adapted for selectively generating positive and negative reference signals for use by said converter means in converting said digital signal to analog form, said reference source means including first means having at least first, second and third terminal means, said first and second terminal means adapted for reception of first and second signals, said first means operating in first and second sequences for selectively presenting said first and second signals at said third terminal means, said first sequence defined by first presenting said first signal at said third terminal means and then presenting said second signal at said third terminal means said second sequence defined by first presenting said second signal at said third terminal means and then presenting said first signal at said third terminal means, second output terminal means, and second means AC coupling said third terminal means and said second output terminal means, a positive reference signal presented at said second output terminal means when said first means is operated in said first sequence, a negative reference signal presented at said second output terminal means when said first means is operated in said second sequence; c. said digital signal at said first input terminal means being presented at said first output terminal means in analog form.
Claim 24
Dependent Claim
119 words
A converter for changing a signal from an input form to an output form, one of said input form and said output form being analog, the other of said input form and said output form being digital, said converter comprising first means responsive to at least a reference signal and at least an unknown signal; reference source means having first and second states, said reference source means generating a positive reference signal when in said first state and a negative reference signal when in said second state, said first and second states determined by the polarity of said unknown signal; and second means for AC coupling said reference signal generated by said reference source means to said first means.
Claim 25
Dependent Claim
119 words
A converter for changing a signal from an input form to an output form, one of said input form and said output form being analog, the other of said input form and said output form being digital, said converter comprising first means responsive to at least a reference signal and at least an unknown signal; reference source means having first and second states, said reference source means generating a positive reference signal when in said first state and a negative reference signal when in said second state, said first and second states determined by the polarity of said unknown signal; and second means for AC coupling said reference signal generated by said reference source means to said first means.
Claim 26
Independent Claim
193 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. capacitor means having first and second terminal means; b. first means having first and second states, said first means operatively connected to said first terminal means for selectively and independently applying at least first and second signals to said first terminal means; and c. second means having first and second states, said second means operatively connected to said second terminal means for selectively applying a return signal to said second terminal means; d. said first signal applied to said first terminal means and coupled to said second terminal means through said capacitor means when said first means is in said first state and said second means is in said second state, said second signal applied to said first terminal means when said first means is in said second state and said second means is in said first state, a reference signal presented at said second terminal means when said second signal is applied to said first terminal means, said reference signal being the difference bEtween said first and second signals with respect to said return signal.
Claim 27
Independent Claim
193 words
A device for presenting a reference signal with respect to a return signal, said device comprising: a. capacitor means having first and second terminal means; b. first means having first and second states, said first means operatively connected to said first terminal means for selectively and independently applying at least first and second signals to said first terminal means; and c. second means having first and second states, said second means operatively connected to said second terminal means for selectively applying a return signal to said second terminal means; d. said first signal applied to said first terminal means and coupled to said second terminal means through said capacitor means when said first means is in said first state and said second means is in said second state, said second signal applied to said first terminal means when said first means is in said second state and said second means is in said first state, a reference signal presented at said second terminal means when said second signal is applied to said first terminal means, said reference signal being the difference bEtween said first and second signals with respect to said return signal.
References Cited (Backward Citations)
US3657563A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |