Barbara J Allen

US Patent:

56082070, Mar 4, 1997

Filed:

May 23, 1995

Appl. No.:

8/449513

Inventors:

Barbara A. Allen - Rockford IL
David A. Klein - Freeport IL
Hongzhi Kong - Freeport IL

Assignee:

Honeywell Inc. - Minneapolis MN

International Classification:

H01J 4014

US Classification:

250214AG

Abstract:

A sensor system is provided with an amplifier that has as an input signal received from a light sensitive component. The output of the amplifier is determined by its gain factor. The output of the amplifier is continually monitored to determine whether it is in acceptable limits. When a change is required, a variable potentiometer is affected to change its resistance. The variable potentiometer is included as part of a feedback loop of the amplifier and, therefore, a change in its resistance will change the gain factor of the amplifier and achieve the appropriate magnitude of output signal from the amplifier. The system can be operated in either a pushbutton mode or an automatic gain control mode. In the pushbutton mode, the system responds to an operator request for a setup procedure to be accomplished. In the automatic gain control mode, the system determines when an object is not present within a detection zone and, using the presently received signal magnitudes, determines the necessary change in gain factor to achieve a signal with an acceptable magnitude.