US3952248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
D.C. voltage ratio measuring circuit
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
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Filing: 1974-09-27
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Granted: 1976-04-20
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Expires: 1994-09-27
Abstract
Abstract A circuit sensitive to the ratio of the values of two voltages of fixed polarities and possibly variable magnitudes, including two identical voltage dividers respectively fed from one and the other of said voltages and a third divider fed from a constant amplitude alternative voltage source. Each divider consists of a constant resistance and of a variable voltage sensitive resistance. The relative positions of the constant and variable resistances are the same in the two first dividers and are reversed in the third one; the latter is biassed by a voltage derived from at least one of the voltages to be compared. From the voltages received at the mid-points of the two first dividers, a resulting voltage is derived, the value of which has a simple relation to the ratio of the compared voltages.
Inventors
- 👤 Claude Hannigsberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:59
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/24; G; G01; G01R; G01R27/00; G01R27/02; G01R27/08; G01R27/10; G01R27/12; G06; G06G; G06G7/00; G06G7/12; G06G7/16; G06G7/163
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
206 words
A measurement circuit for measuring the ratio of the magnitudes of two D-C voltages of fixed polarity and translating said ratio into a representing voltage, comprising three voltage dividers connected to a common ground point and each consisting of a fixed resistor and a variable resistor having a resistance value sensitive to the voltage applied thereto, wherein a first and a second of said dividers are respectively fed with direct current by said D-C voltages of fixed polarity, while the third of said dividers is fed with a direct current by means of a further D-C voltage derived from at least one of said D-C voltages of fixed polarity and with an alternating current voltage delivered by a source of constant amplitude, wherein the alternating current voltage appearing at the mid-point of said third divider feeds both said first and second dividers, wherein the series-connection order with respect to ground of said fixed and variable resistors is the same in said first and second dividers and is reversed in said third divider, and wherein the difference between the alternating current voltages received at the mid-points of said first and second dividers is converted into said representing voltage by amplification, rectification and filtering in an output circuit.
Claim 2
Dependent Claim
206 words
A measurement circuit for measuring the ratio of the magnitudes of two D-C voltages of fixed polarity and translating said ratio into a representing voltage, comprising three voltage dividers connected to a common ground point and each consisting of a fixed resistor and a variable resistor having a resistance value sensitive to the voltage applied thereto, wherein a first and a second of said dividers are respectively fed with direct current by said D-C voltages of fixed polarity, while the third of said dividers is fed with a direct current by means of a further D-C voltage derived from at least one of said D-C voltages of fixed polarity and with an alternating current voltage delivered by a source of constant amplitude, wherein the alternating current voltage appearing at the mid-point of said third divider feeds both said first and second dividers, wherein the series-connection order with respect to ground of said fixed and variable resistors is the same in said first and second dividers and is reversed in said third divider, and wherein the difference between the alternating current voltages received at the mid-points of said first and second dividers is converted into said representing voltage by amplification, rectification and filtering in an output circuit.
Claim 3
Dependent Claim
69 words
A measurement circuit according to claim 1, wherein the said variable resistors are semi-conductor rectifying diodes, each one of which is biassed by means of a fixed biassing resistor having a very high resistance value compared with the maximum direct current resistance values of said diodes, said biassing resistor being connected in series with that of said first and second voltage dividers which includes said one of said diodes.
Claim 4
Dependent Claim
25 words
A measurement circuit according to claim 2, wherein the variable resistors of said first and second dividers are both connected to said common ground point.
Claim 5
Dependent Claim
98 words
A measurement circuit according to claim 2, wherein the variable resistors of said first and second voltage dividers are both connected to a common ground point and wherein the fixed resistors in said first and second voltage dividers are of large resistance values in comparison with the highest possible values of the differential resistances of the diodes included in said first and second dividers, and wherein the fixed resistor of said third voltage divider has a small resistance value compared with the lowest possible values of the differential resistance of the diode included in said third voltage divider.
Claim 6
Dependent Claim
25 words
A measurement circuit according to claim 2, wherein the fixed resistors of said first and second dividers are both connected to a common ground point.
Claim 7
Dependent Claim
76 words
A measurement circuit according to claim 5, wherein the resistances of said fixed resistors in said first and second voltage dividers are small compared with the smallest possible values of the differential resistances of the diodes included in said first and second dividers and wherein in said third voltage divider the resistance of the fixed resistor is large compared with the highest possible value of the differential resistance of the diode included in said third divider.
Claim 8
Dependent Claim
48 words
A measurement circuit according to claim 6, wherein said third voltage divider is fed with a direct current by one of said voltages of fixed polarity through a further fixed resistor of large resistance value compared with the direct-current resistance of the diode included in said third divider.
Claim 9
Dependent Claim
48 words
A measurement circuit according to claim 6, wherein said third voltage divider is fed with a direct current by both said voltages of fixed polarity through two further fixed resistors of large resistance value compared with the direct-current resistance of the fixed resistor included in said third divider.
Claim 10
Dependent Claim
37 words
A measurement circuit according to claim 2, wherein the ratio of the resistance of said fixed biassing resistor to that of the resistance of said fixed resistor is the same for both said first and second dividers.
Claim 11
Dependent Claim
80 words
A measurement circuit according to claim 9, wherein the two alternating current voltages received at the mid-points of said first and second voltage dividers are respectively amplified, rectified and filtered in two distinct similar circuits respectively connected to two inputs of a symmetrical amplifier circuit delivering an amplified signal to either of two outputs, depending on the sign of the difference of the amplitudes of said alternating current voltages, said two outputs being connected to an output and utilization circuit.
Claim 12
Dependent Claim
54 words
A measurement circuit according to claim 9, wherein the two alternating current voltages received at the mid-points of said first and second dividers are applied to a linear differential amplifier having an output connected to the input of a rectifying and filtering circuit, the output voltage of which supplies an output and utilization circuit.
References Cited (Backward Citations)
US2521522A
Cited
US3710253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-20 | 1979-10-20 | 1980-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-20 | 1983-10-20 | 1984-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-20 | 1987-10-20 | 1988-04-20 | $7700.00 | Window Closed / Lapsed |