Electronic circuit for automatic DC offset compensation for...

Electricity: measuring and testing – Magnetic – Displacement

Reexamination Certificate

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C324S225000, C702S094000

Reexamination Certificate

active

06198275

ABSTRACT:

MICROFICHE APPENDIX
This application includes a microfiche appendix consisting of two microfiche having total of 111 frames.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic compensation circuit for use with a linear displacement type sensor which dynamically compensates for errors in the sensor output signal based upon ideal values stored in electronic memory.
2. Description of the Prior Art
Various linear type displacement sensors, such as angular position sensors, are known to be used for various purposes including throttle position sensors for determining the angular position of a butterfly valve in a throttle body. Examples of such sensors are disclosed in U.S. Pat. Nos. 4,893,502 and 5,332,965. Such sensors are generally used to control the amount of fuel applied to the combustion chamber of an internal combustion engine.
Such throttle position sensors, such as the sensors disclosed in U.S. Pat. Nos. 4,893,502 and 5,332,956, are typically subject to part-to-part variations which require each and every sensor to be calibrated either by the throttle body manufacturer as in the case of U.S. Pat. No. 4,893,502 or the sensor manufacturer as in the case of U.S. Pat. No. 5,332,965. In the embodiment disclosed in the '502 patent, a circular magnet is rigidly secured directly to the butterfly valve shaft. A magnetic resistive element (MRE) is disposed within a modified throttle body at a fixed air gap relative to the circular magnet. An amplifying circuit with variable gain is used to calibrate the sensor by way of potentiometers or variable resistors.
As is known in the art, the output of such potentiometers may vary with temperature or time. Due to the relatively wide operating temperature range of such a sensor used in an internal combustion engine environment, such potentiometers will drift and affect the overall calibration of the device. The sensor disclosed in the '965 patent is mechanically adjusted; and thus, the calibration is not subject to drift as in the case of the '502 patent. However, such mechanical adjustments are time-consuming and cumbersome, which increases the overall labor cost to manufacture the product.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve various known problems in the prior art.
It is yet another object of the present invention to provide circuitry for automatically compensating for errors in the output signal of a linear type displacement signal.
Briefly, the present invention relates to electronic circuitry for automatically compensating for errors in the output signal of a displacement sensor. The electronic circuitry includes an analog to digital converter (ADC) for digitizing an analog output signal from a linear displacement type sensor. The digitized output signal from the (ADC) is processed by a microcontroller to automatically compensate for errors in the output signal. Ideal values, stored in an electronic memory, are used for compensation.


REFERENCES:
patent: 2942177 (1960-06-01), Neumann et al.
patent: 2992369 (1961-07-01), LaRocca
patent: 3060370 (1962-10-01), Varterasian
patent: 3112464 (1963-11-01), Ratajski et al.
patent: 3118108 (1964-01-01), Zoss
patent: 3185920 (1965-05-01), Brunner
patent: 3473109 (1969-10-01), Maaz et al.
patent: 3482163 (1969-12-01), Peek et al.
patent: 3818292 (1974-06-01), Berman
patent: 3988710 (1976-10-01), Sidor et al.
patent: 4066962 (1978-01-01), Jaffe
patent: 4074186 (1978-02-01), Flaherty
patent: 4086533 (1978-04-01), Ricouard et al.
patent: 4107604 (1978-08-01), Bernier
patent: 4156191 (1979-05-01), Knight et al.
patent: 4293814 (1981-10-01), Boyer
patent: 4293837 (1981-10-01), Jaffe et al.
patent: 4371837 (1983-02-01), Sieverin
patent: 4377088 (1983-03-01), Evert
patent: 4392375 (1983-07-01), Eguchi et al.
patent: 4524932 (1985-06-01), Bodziak
patent: 4570118 (1986-02-01), Tomczak et al.
patent: 4731579 (1988-03-01), Peterson et al.
patent: 4745363 (1988-05-01), Carr et al.
patent: 4771237 (1988-09-01), Daley
patent: 4798920 (1989-01-01), Makino et al.
patent: 4829248 (1989-05-01), Loubier
patent: 4857842 (1989-08-01), Sturman et al.
patent: 4873655 (1989-10-01), Kondraske
patent: 4893502 (1990-01-01), Kubota et al.
patent: 4922197 (1990-05-01), Juds
patent: 4970463 (1990-11-01), Wolf et al.
patent: 4992731 (1991-02-01), Lorenzen
patent: 5045920 (1991-09-01), Vig et al.
patent: 5087879 (1992-02-01), Sugifune et al.
patent: 5144231 (1992-09-01), Tenebaum et al.
patent: 5144233 (1992-09-01), Christenson et al.
patent: 5159268 (1992-10-01), Wu
patent: 5164668 (1992-11-01), Alfors
patent: 5274328 (1993-12-01), Begin et al.
patent: 5283521 (1994-02-01), Ottesen et al.
patent: 5285154 (1994-02-01), Burreson
patent: 5305241 (1994-04-01), Hayashi et al.
patent: 5311124 (1994-05-01), Hubbard et al.
patent: 5332965 (1994-07-01), Wolf et al.
patent: 5341097 (1994-08-01), Wu
patent: 5351003 (1994-09-01), Bauer et al.
patent: 5363361 (1994-11-01), Bakx
patent: 5369361 (1994-11-01), Wada
patent: 5389889 (1995-02-01), Towne et al.
patent: 5406200 (1995-04-01), Begin et al.
patent: 5497081 (1996-03-01), Wolf
patent: 5650719 (1997-07-01), Moody et al.
patent: 5694038 (1997-12-01), Moody et al.
patent: 5729130 (1998-03-01), Moody et al.
patent: 5757181 (1998-05-01), Wolf et al.
patent: 31 50 013 (1983-06-01), None
patent: 4 014 885 (1990-11-01), None
patent: 296 22 602 U (1997-04-01), None
patent: 0 053 938 (1982-06-01), None
patent: 0 363 738 (1989-09-01), None
patent: 0 0780592 (1995-12-01), None
patent: 1 416 925 (1975-12-01), None
patent: 2 221 039 (1990-01-01), None
patent: 2 251 948 (1992-07-01), None
patent: 2 297 622 (1996-08-01), None
patent: 56 107 119 (1981-08-01), None
patent: 82 03121 (1982-09-01), None
patent: WO 88/07172 (1988-09-01), None
patent: WO 94/12940 (1994-06-01), None
A Smart Pressure Sensor with On-Chip Calibration and Compensation Capability by E. Obermeier et al.,Sensors, Mar., 1995, pp. 20, 21, 52 and 53.
Ravi, Vig, “Power Hall-Effect Sensor Take to the Road,”Machine Design, Aug. 23, 1990, pp. 113-119.

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