Patent US5336258A successfully refreshed from Google Patents.
Patent US3893192A successfully refreshed from Google Patents.
US3893192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Converter for measured quantities
Assignee: Danfoss AS
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Filing: 1974-03-13
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Granted: 1975-07-01
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Expires: 1994-03-13
Abstract
Abstract The invention relates to a converter for measured quantities comprising at least one measuring resistance provided in a compensating bridge, the signal current for restoring the bridge balance being fed through a part of the fixed resistances of the bridge. The output that is required for operation is derived from the supervising current. The bridge is connected in series with a control element which varies the voltage across the bridge in such a way that the sum of the currents flowing through the entire bridge is substantially constant, the voltage drop at one of the fixed bridge resistances being used to form a control signal for influencing the control element. In a preferred form of the invention the bridge comprises first and second branches connected to a feed point with each branch consisting of a fixed resistance serving to form the control signal. A third branch comprises a fixed resistance with a tap for connecting the current path for the signal current and the first branch comprises at least one measuring resistance. This results in a very simply constructed bridge which, in the extreme case, makes do with four bridge elements which are two fixed resistances, a fixed resistance with a tap and a measuring resistance.
Inventors
- 👤 Arne Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:49
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G08; G08C; G08C19/00; G08C19/02; G08C19/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
141 words
An electric circuit arrangement for supplying an electric signal current in dependence upon a measured value of a physical quantity, the circuit arrangement comprising a compensating bridge circuit having a plurality of arms including fixed value resistances and at least one measuring resistance, in which bridge circuit the signal current is supplied through at least one of said fixed value resistances for restoring the balance of the bridge circuit, a control element connected in series with the bridge circuit, and means to derive a control signal in dependence upon the voltage drop across at least one of the other of said fixed value resistances and to supply said control signal to said control element whereby the control element varies the voltage across the bridge circuit such that the sum of the currents flowing through the bridge circuit is maintained substantially constant.
Claim 2
Dependent Claim
141 words
An electric circuit arrangement for supplying an electric signal current in dependence upon a measured value of a physical quantity, the circuit arrangement comprising a compensating bridge circuit having a plurality of arms including fixed value resistances and at least one measuring resistance, in which bridge circuit the signal current is supplied through at least one of said fixed value resistances for restoring the balance of the bridge circuit, a control element connected in series with the bridge circuit, and means to derive a control signal in dependence upon the voltage drop across at least one of the other of said fixed value resistances and to supply said control signal to said control element whereby the control element varies the voltage across the bridge circuit such that the sum of the currents flowing through the bridge circuit is maintained substantially constant.
Claim 3
Dependent Claim
60 words
A circuit arrangement according to claim 1 wherein said means to derive a control signal comprises means for deriving the mean value of the voltage drop across said fixed value resistances in two of said arms of said bridge circuit, and for comparing the means value so obtained with a constant voltage for the purpose of forming said control signal.
Claim 4
Dependent Claim
89 words
A circuit arrangement according to claim 2 wherein said bridge circuit comprises first, second, third and fourth arms, and first and second feed points connected to the junctions of said first and second and said third and fourth arms respectively, and wherein said first and second arms each comprise a fixed value resistance, said third arm comprises a fixed value resistance having an intermediate tap, a path being connected to said intermediate tap for carrying said signal current, and said fourth arm comprises at least one said measuring resistance.
Claim 5
Dependent Claim
33 words
A circuit arrangement according to claim 3 wherein said third arm comprises a said measuring resistance, the values of said measuring resistances in said third and fourth arms varying in opposite senses respectively.
Claim 6
Dependent Claim
102 words
A circuit arrangement according to claim 2 wherein said means to derive a control signal comprises a transistor differential amplifier comprising a pair of transistors each having base, emitter and collector, and a common emitter resistance, the base of one transistor of said pair being connected to the junction of said second and third arms and the base of the other transistor of said pair being connected to the junction of said first and fourth arms and a transistor amplifier for comparing the voltage drop across said common emitter resistance with a constant voltage for the purpose of forming said control signal.
Claim 7
Dependent Claim
87 words
A circuit arrangement according to claim 5 wherein said transistor amplifier comprises a transistor having base, emitter and collector which is complementary to said transistor of the differential amplifier, the base of said transistor of the transistor amplifier being connected to the emitters of the transistors of the differential amplifier, the emitter of said transistor of the transistor amplifier being fed with said constant voltage, and the collector of said transistor of the transistor amplifier being connected to said control element which comprises a further transistor amplifier.
Claim 8
Dependent Claim
37 words
A circuit arrangement according to claim 2 wherein said means for deriving the mean value of the voltage drop across said fixed value resistances in two of said arms of said bridge circuit comprises a voltage divider.
Claim 9
Dependent Claim
76 words
A circuit arrangement according to claim 1 comprising further means to derive a further signal current for restoring the balance of said bridge circuit, said bridge circuit having a diagonal and said means to derive said first-mentioned signal current operating when the voltage across said diagonal deviates from zero in one sense, and said further means to derive a further control signal operating when said voltage across said diagonal deviates from zero in the other sense.
Claim 10
Dependent Claim
41 words
A circuit arrangement according to claim 8 wherein said further means to derive a further signal current comprises a controllable resistance connected in parallel with part of a said fixed value resistance in one of said arms of said bridge circuit.
Claim 11
Dependent Claim
27 words
A circuit arrangement according to claim 9 comprising a transistor having base, collector and emitter, said controllable resistance being formed by the collector-emitter path of said transistor.
Claim 12
Dependent Claim
65 words
A circuit arrangement according to claim 7 comprising a transistor differential amplifier having an output and two control inputs respectively connected to said voltage divider and also to the junction of said fixed value resistances in two of said arms of said bridge circuit and to said constant voltage, and a further transistor, said output being connected via said further transistor to said control element.
Claim 13
Dependent Claim
159 words
A bridge circuit for use in measuring a physical quantity, said bridge circuit having four terminals which form respectively two feed points for connection to a power supply and intermediate between said two feed points two diagonal points, and four branches connecting said points in pairs, a detector circuit connected between said two diagonal joints, said detector circuit providing an output for controlling a signal current in response to differences in voltage between said two diagonal points, said signal current passing through a part of the bridge circuit and reStoring the bridge circuit to a balanced condition, means for generating a control signal in response to a mean value of the voltage differences across two said branches of said bridge circuit, and a control element connected in series with said bridge circuit, said control signal being applied to said control element to maintain the net current flowing out of one of said feed points at a substantially constant value.
Claim 14
Dependent Claim
159 words
A bridge circuit for use in measuring a physical quantity, said bridge circuit having four terminals which form respectively two feed points for connection to a power supply and intermediate between said two feed points two diagonal points, and four branches connecting said points in pairs, a detector circuit connected between said two diagonal joints, said detector circuit providing an output for controlling a signal current in response to differences in voltage between said two diagonal points, said signal current passing through a part of the bridge circuit and reStoring the bridge circuit to a balanced condition, means for generating a control signal in response to a mean value of the voltage differences across two said branches of said bridge circuit, and a control element connected in series with said bridge circuit, said control signal being applied to said control element to maintain the net current flowing out of one of said feed points at a substantially constant value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |