Patent US3585528A successfully refreshed from Google Patents.
US3585528A
Expired / Lapsed
US
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Hall-effect modulator including distortion suppression means
Assignee: AT&T Inc
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Filing: 1968-10-28
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Granted: 1971-06-15
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Expires: 1988-10-28
Abstract
Abstract In practical Hall-effect modulators, unwanted signal components, for example, carrier frequency harmonics and magnetic field components, appear in the output signal. These unwanted signal components are suppressed by selectively shaping a face of a magnetic core member of the modulator to introduce an inhomogeneity into the magnetic field applied to the Hall element. Further suppression of unwanted signal components is achieved by utilizing a potentiometer connected between output terminals of the Hall element and an additional terminal substantially in the center of the element.
Inventors
- 👤 Robert L Wallace Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:29
CPC Classifications
H; H03; H03B; H03B19/00; H10; H10N; H10N52/00; H10N52/80
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
301 words
Hall-effect modulator apparatus which comprises, a first magnetic core member having a pole face, a second magnetic core member having a pole face, said magnetic core members being in a predetermined spatial relationship so that said pole faces are in substantially parallel planes defining an air gap, at least one of said pole faces having a centrally located unnotched area and first and second notched areas symmetrically disposed on either side of said unnotched area to establish within said air gap in response to a magnetic flux induced in said magnetic core members a first magnetic field region having a first field intensity and a second magnetic field region having a second field intensity less than said first field intensity, said notched areas being substantially smaller than said unnotched area, coil means in juxtaposition to said magnetic core members for inducing said magnetic flux in said magnetic core members in response to a current supplied to said coil means, and a rectangular semiconductor plate having opposite faces and first and second input terminals and first and second output terminals symmetrically located on one of said opposite faces, said semiconductor plate being responsive to said magnetic fields and signals supplied to said input terminals for controllably developing signals which appear at said output terminals, wherein the width of said unnotched area of said pole face is smaller than the width of said semiconductor plate and wherein said semiconductor plate is symmetrically disposed within said air gap in substantially parallel alignment with said pole faces so that said first and second magnetic fields induced in said air gap are applied to said opposite faces of said semiconductor plate substantially to suppress unwanted signal components developed in said semiconductor plate because of inherent limitations including variations in resistivity and thickness of said semiconductor plate.
Claim 2
Dependent Claim
301 words
Hall-effect modulator apparatus which comprises, a first magnetic core member having a pole face, a second magnetic core member having a pole face, said magnetic core members being in a predetermined spatial relationship so that said pole faces are in substantially parallel planes defining an air gap, at least one of said pole faces having a centrally located unnotched area and first and second notched areas symmetrically disposed on either side of said unnotched area to establish within said air gap in response to a magnetic flux induced in said magnetic core members a first magnetic field region having a first field intensity and a second magnetic field region having a second field intensity less than said first field intensity, said notched areas being substantially smaller than said unnotched area, coil means in juxtaposition to said magnetic core members for inducing said magnetic flux in said magnetic core members in response to a current supplied to said coil means, and a rectangular semiconductor plate having opposite faces and first and second input terminals and first and second output terminals symmetrically located on one of said opposite faces, said semiconductor plate being responsive to said magnetic fields and signals supplied to said input terminals for controllably developing signals which appear at said output terminals, wherein the width of said unnotched area of said pole face is smaller than the width of said semiconductor plate and wherein said semiconductor plate is symmetrically disposed within said air gap in substantially parallel alignment with said pole faces so that said first and second magnetic fields induced in said air gap are applied to said opposite faces of said semiconductor plate substantially to suppress unwanted signal components developed in said semiconductor plate because of inherent limitations including variations in resistivity and thickness of said semiconductor plate.
Claim 3
Dependent Claim
118 words
A Hall-effect modulator as defined in claim 1 wherein said semiconductor plate has an additional terminal located at a position between and in alignment with said first and second output terminals, said location of said additional terminal being substantially at the geometric center of said face of said semiconductor plate, and further includes potentiometer means having a first terminal, a second terminal and a wiper arm, said first and second terminals of said potentiometer means being connected to said first and second output terminals, respectively, and said wiper arm being connected to said additional terminal for balancing the magnitude of selected unwanted potentials developed in said semiconductor plate in response to eddy currents induced by said magnetic fields.
Claim 4
Dependent Claim
58 words
A Hall-effect modulator as defined in claim 1 wherein at least one of said magnetic core members is moveably related to the other of said magnetic core members for selectively positioning said first and second magnetic field regions in spatial relationship with the faces of said semiconductor plate so that suppression of said unwanted signal components is maximized.
Claim 5
Dependent Claim
191 words
Hall-effect signal multiplication apparatus of the type including a semiconductor plate having opposite faces and a thicknEss substantially smaller than the length or width of the faces, said semiconductor plate having input terminals and first and second output terminals symmetrically positioned on one of said opposite faces of said semiconductor plate and said semiconductor plate being responsive to a substantially uniform magnetic field applied to said faces and signals supplied to said input terminals for controllably developing signals at said output terminals, wherein the improvement comprises, an additional terminal located at a position between and in alignment with said first and second output terminals, said location of said additional terminal being substantially at the geometric center of said opposite face of said semiconductor plate, and adjustable resistor means having a first terminal, a second terminal and a wiper arm, said first and second terminals of said resistor means being connected to said first and second output terminals, respectively, and said wiper arm being connected to said additional terminal for balancing the magnitude of selected unwanted potentials developed in said semiconductor plate in response to eddy currents induced by said magnetic field.
Claim 6
Dependent Claim
191 words
Hall-effect signal multiplication apparatus of the type including a semiconductor plate having opposite faces and a thicknEss substantially smaller than the length or width of the faces, said semiconductor plate having input terminals and first and second output terminals symmetrically positioned on one of said opposite faces of said semiconductor plate and said semiconductor plate being responsive to a substantially uniform magnetic field applied to said faces and signals supplied to said input terminals for controllably developing signals at said output terminals, wherein the improvement comprises, an additional terminal located at a position between and in alignment with said first and second output terminals, said location of said additional terminal being substantially at the geometric center of said opposite face of said semiconductor plate, and adjustable resistor means having a first terminal, a second terminal and a wiper arm, said first and second terminals of said resistor means being connected to said first and second output terminals, respectively, and said wiper arm being connected to said additional terminal for balancing the magnitude of selected unwanted potentials developed in said semiconductor plate in response to eddy currents induced by said magnetic field.
Claim 7
Dependent Claim
28 words
Apparatus as defined in claim 1, wherein said notched pole face is substantially circular having a raised portion thereon bounded by substantially parallel chords of said circular face.
Claim 8
Dependent Claim
17 words
Apparatus as defined in claim 1, wherein said rectangular semiconductor plate is an epitaxial indium arsenide semiconductor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |