Patent US4465976A successfully refreshed from Google Patents.
US4465976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hall element with bucking current and magnet biases
Assignee: Allegro Microsystems LLC
•
Filing: 1982-01-26
•
Granted: 1984-08-14
•
Expires: 2002-01-26
Abstract
Abstract A strong magnet is bonded to a conventional Hall element package. A bias current is introduced at one of the output terminals of the Hall element in the direction to cause a reduction in the magnet-bias-induced output voltage. This output voltage is easily reduced by this means to zero. The resulting Hall-element detector is shrouded by a large magnetic biasing field while presenting a low or zero DC output component upon which the signal voltage will be superimposed.
Inventors
- 👤 Grant D. Avery
- 👤 Jacob K. Higgs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:08
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/07; H; H10; H10N; H10N52/00; H10N52/80
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
120 words
A ferromagnetic-material detector comprising a Hall element and a magnet being fixedly mounted therewith to produce a magnet-bias flux through said Hall element for producing a magnet-bias-induced Hall voltage across the output terminals of said Hall element, and a bias current generator means being connected to at least one of said Hall element output terminals to cancel at least a portion of said magnetic-bias-induced voltage, said detector further comprising two energizing terminals through which an energizing current maybe introduced into the body of said Hall element from a DC power supply, said bias current generator being comprised of a current-mirror circuit that is connected between said at least one Hall element output terminal and one of said DC energizing terminals.
Claim 2
Dependent Claim
120 words
A ferromagnetic-material detector comprising a Hall element and a magnet being fixedly mounted therewith to produce a magnet-bias flux through said Hall element for producing a magnet-bias-induced Hall voltage across the output terminals of said Hall element, and a bias current generator means being connected to at least one of said Hall element output terminals to cancel at least a portion of said magnetic-bias-induced voltage, said detector further comprising two energizing terminals through which an energizing current maybe introduced into the body of said Hall element from a DC power supply, said bias current generator being comprised of a current-mirror circuit that is connected between said at least one Hall element output terminal and one of said DC energizing terminals.
Claim 3
Dependent Claim
35 words
The detector of claim 1 wherein said bias current is of a magnitude for said current-induced opposite-polarity voltage to equal said magnet-bias-induced Hall voltage and produce a near zero net voltage across said output terminals.
Claim 4
Dependent Claim
35 words
The detector of claim 1 wherein said bias current generator means is additionally comprised of another current-mirror circuit connected between the other side of said DC power supply and the other of said output terminals.
Claim 5
Dependent Claim
24 words
The detector of claim 3 wherein the amplitude of the bias currents established by each of said two current mirror circuits are substantially equal.
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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |