Title:
A SOLID STATE COMPASS
Document Type and Number:
WIPO Patent Application WO/1991/015778
Kind Code:
A1
Abstract:
A solid state compass uses arrays of Hall effect devices for indicating direction. The Hall effect devices (H1, H2) in an array are arranged in parallel and electrically coupled in series, the outputs of this array of the Hall effect devices are amplified by difference amplifier (OP1). The difference amplifier's outputs are fed to a polarity recovery circuit (OP2, OP3) to recover its original voltage polarity for the correct sensing of the polarity of the magnetic field. The output signals from the polarity recovery circuits are then processed by the largest voltage sensing circuit (T1, T2) to sense the largest possible magnitude of the amplified signals. This signal is then stored to a buffer (L1) controlled by a logic control circuit (I1, I2, I3, I4, I5), which is also used to reset the largest voltage sensing circuit. The buffer output is used by display driver and display element (D1, LED) for indicating the sensed direction. Additional arrays of Hall effect devices can be configured to improve directional resolution.
Inventors:
NG KIM KWEE (US)
Application Number:
PCT/US1990/002236
Publication Date:
October 17, 1991
Filing Date:
April 23, 1990
Export Citation:
Assignee:
NG KIM KWEE (US)
International Classes:
G01C17/28; G01C17/30; (IPC1-7): G01R33/06
Foreign References:
| US4163326A | 1979-08-07 | |||
| US3197880A | 1965-08-03 | |||
| US3622898A | 1971-11-23 | |||
| US3906641A | 1975-09-23 | |||
| US4373271A | 1983-02-15 | |||
| US4518918A | 1985-05-21 | |||
| US4692702A | 1987-09-08 | |||
| US4656750A | 1987-04-14 | |||
| US4737710A | 1988-04-12 | |||
| US4857842A | 1989-08-15 |
Other References:
See also references of EP 0504139A4
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