US4074781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetically compensating weighing or dynamometer apparatus
Assignee: Sartorius Werke GmbH
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Filing: 1976-06-17
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Granted: 1978-02-21
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Expires: 1996-06-17
Abstract
Abstract Electromagnetically compensating weighing or dynamometer apparatus in which coil moves out of an equilibrium position relative to a magnet under the influence of a force, including a compensating circuit providing a compensation current proportional to the amplitude of the deflection, an a taring arrangement comprising a store and a digital/analog converter connected to the coil in parallel to the compensation circuit.
Inventors
- 👤 Franz Josef Melcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:54
CPC Classifications
G; G01; G01G; G01G7/00; G01G7/02; G01G7/04; G01G23/00; G01G23/14; G01G23/16; G01G23/163
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
193 words
An electromagnetically compensating weighing or dynamometer apparatus comprising: a coil provided in a working gap of a magnet, said coil being operatively associated with a movable part of the apparatus and being deflected under action of a force out of a preadjusted position of equilibrium in relation to said magnet; a compensation circuit which includes a position indicator coupled to said coil, a power amplifier responsive to position of said indicator, and said coil and which, when a deflection occurs, allows a compensation current proportional to the amplitude of the deflection to flow through said coil; an analog-digital (A/D) converter coupled to said compensating circuit and responsive to an output therefrom and having its output coupled to a digitally operating measurement indicator; and a taring arrangement which includes, connected in series, a store and a digital-analog (D/A) converter, an input of said store being coupled to an output of said A/D converter which is coupled with said measurement indicator, and an output of said D/A converter being connected to said coil, forming a taring circuit having its output coupled in parallel to that portion of said compensation circuit exclusive of said compensation coil.
Claim 2
Dependent Claim
193 words
An electromagnetically compensating weighing or dynamometer apparatus comprising: a coil provided in a working gap of a magnet, said coil being operatively associated with a movable part of the apparatus and being deflected under action of a force out of a preadjusted position of equilibrium in relation to said magnet; a compensation circuit which includes a position indicator coupled to said coil, a power amplifier responsive to position of said indicator, and said coil and which, when a deflection occurs, allows a compensation current proportional to the amplitude of the deflection to flow through said coil; an analog-digital (A/D) converter coupled to said compensating circuit and responsive to an output therefrom and having its output coupled to a digitally operating measurement indicator; and a taring arrangement which includes, connected in series, a store and a digital-analog (D/A) converter, an input of said store being coupled to an output of said A/D converter which is coupled with said measurement indicator, and an output of said D/A converter being connected to said coil, forming a taring circuit having its output coupled in parallel to that portion of said compensation circuit exclusive of said compensation coil.
Claim 3
Dependent Claim
23 words
An apparatus according to claim 1, wherein the compensation circuit comprises a measuring resistor across which the A/D converter is connected in parallel.
Claim 4
Dependent Claim
18 words
An apparatus according to claim 2, wherein the taring circuit comprises an adder connected upstream of the store.
Claim 5
Dependent Claim
63 words
An apparatus according to claim 1, wherein the compensation circuit comprises, in series connection, a forward-backward counter which is operated in dependence on the direction of the deflection and which, together with a timing oscillator, forms the A/D converter, and a D/A converter whose digital input is connected to the output of the counter and whose analog output is connected to the coil.
Claim 6
Dependent Claim
38 words
An apparatus according to claim 4, wherein the taring circuit includes a forward-backward counter which is connected upstream of the store and whose inputs are connected to the corresponding inputs of the forward-backward counter in the compensation circuit.
Claim 7
Dependent Claim
34 words
An apparatus according to claim 1, wherein the taring circuit comprises a control unit which, on operation of an associated taring key, repeats the taring operation until the measurement indicator indicates the value zero.
Claim 8
Dependent Claim
29 words
An apparatus according to claim 1 wherein the D/A converter in the compensation circuit and/or the D/A converter in the taring circuit is or are provided with reference means.
Claim 9
Dependent Claim
14 words
An apparatus according to claim 7, wherein the reference means is a zener diode.
Claim 10
Dependent Claim
14 words
An apparatus according to claim 7, wherein the reference means is a mass reference.
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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |