William M Tuttle

US Patent:

47679409, Aug 30, 1988

Filed:

Oct 2, 1987

Appl. No.:

7/104825

Inventors:

William C. Tuttle - Marietta GA

Assignee:

Peachtree Patient Center, Inc. - Atlanta GA

International Classification:

H02P 768

US Classification:

307116

Abstract:

An electronic sensing and control circuit is provided which includes a sensing plate and means for charging the sensing plate to a value dependent upon the capacitance existing between the sensing plate and a remote object. The capacitance between the sensing plate and the object varies with the distance of the object relative to the sensing plate. The sensing plate is periodically discharged and charged producing a useful current proportional to the capacitance and varying with the distance between the sensing plate and the object. Two sensing plates are used to provide first and second signals. The first and second signals are subtracted to derive a lateral displacement signal and added to derive a distance signal. The lateral displacement signal and the distance signal can be used to control the forward, reverse and turning motion of a motorized wheelchair.