Chen S Lee

US Patent:

44676557, Aug 28, 1984

Filed:

Sep 23, 1982

Appl. No.:

6/422234

Inventors:

Chen Y. Lee - Troy MI

Assignee:

C & J Industries, Inc. - Troy MI

International Classification:

G01L 1904
H03K 902

US Classification:

73724

Abstract:

A quad-gate demodulator circuit for capacitive transducers in which analog gate devices replace the diodes of a prior art diode-quad bridge circuit. This improvement eliminates the temperature and ratiometricity errors associated with the diode-quad circuit.

US Patent:

42890357, Sep 15, 1981

Filed:

Nov 30, 1978

Appl. No.:

5/965453

Inventors:

Chen Y. Lee - Troy MI

Assignee:

The Bendix Corporation - Southfield MI

International Classification:

G01L 1904

US Classification:

73708

Abstract:

A compensation technique and network circuitry for a quad-diode demodulator and capacitive transducer combination is disclosed. The compensation method includes varying the amplitude of an alternating carrier frequency oppositely to the changes produced in that amplitude by the compensable errors in the demodulator and transducer. In one preferred embodiment ratiometric compensation and temperature compensation for the demodulator and any capacitive transducer is produced. In a second embodiment linearization and temperature compensation for the demodulator and a quartz capacitive transducer is provided.

US Patent:

43984266, Aug 16, 1983

Filed:

Jul 2, 1981

Appl. No.:

6/279938

Inventors:

Kyong Park - Chatsworth CA
Chen Y. Lee - Troy MI

Assignee:

Kavlico Corporation - Chatsworth CA

International Classification:

G01L 912

US Classification:

73724

Abstract:

A capacitive pressure transducer system includes a reference capacitor and a capacitor which varies with pressure; and circuitry which involves alternately charging one of the capacitors to a reference voltage level, and then switching to charge the other capacitor; and circuitry for producing an output voltage which varies as the duty cycles of the two capacitors shift; and the output is therefore substantially proportional to the pressure changes. Feedback is provided to incrementally change the capacitor charging and switching timing or duty cycles by changing the charging current or the reference voltage at which switching occurs, to substantially eliminate deviations from linearity in the voltage versus pressure characteristic.

US Patent:

42888352, Sep 8, 1981

Filed:

Apr 16, 1979

Appl. No.:

6/030589

Inventors:

Chen Yi Lee - Troy MI
Charles Tung-ming Wu - Troy MI
Mark A. Brooks - Sterling Heights MI
Robert E. Fallis - Milford MI

Assignee:

The Bendix Corporation - Southfield MI

International Classification:

H01G 700

US Classification:

361283

Abstract:

A pressure sensor including a pressure capsule such as a dual diaphragm quartz capacitance pressure capsule and structure for supporting and sealing same within the pressure environment to be measured. The pressure capsule having two parallel quartz plates spaced by a dielectric ring forming a vacuum chamber therein. The structure providing a force balanced support for compressively loading the pressure capsule through the dielectric ring. The structure further having transfer port therein to communicate the pressure environment to both plates.

US Patent:

40216799, May 3, 1977

Filed:

Oct 22, 1975

Appl. No.:

5/625359

Inventors:

Fred Bolle - Troy MI
Chen Yi Lee - Troy MI
Daniel A. Tardiff - Troy MI

International Classification:

H01H 4712

US Classification:

307117

Abstract:

A method and apparatus for automatically switching a circuit to regulate artificial light in an area. The artificial light is turned on by a person entering the area and reflecting an ultrasonic wave pattern toward a receiver. The light is turned off by a person moving into contactless proximity of a capacitance comparison circuit which utilizes the capacitance of the human body as one of the circuit elements. The ultrasonic circuit operates at different levels of sensitivity, depending upon the existing available light in the area, such as during daylight hours. Optionally, a capacitance comparison circuit may be utilized for both turning on and turning off of the artificial light.