The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 22, 1992
Filed:
May. 20, 1991
David P Orlowski, Clinton, MI (US);
Larry Eccleston, Marshall, MI (US);
Earl R Goodrich, II, East Lansing, MI (US);
Microwave Sensors, Ann Arbor, MI (US);
Abstract
A field disturbance monitor system which senses changes in a reflected signal caused by animate objects compared to inanimate objects in the same zone. The system employs a microprocessor which controls the system. A transmitter transmits a pulses microwave signal in response to a control signal from the microprocessor. A receiver receives a return signal which represents a reflection of the transmitted signal. A sample and hold circuit senses and holds the magnitude of the pulsed signal. Analog to digital conversion is obtained, whereby a ramp generator generates a ramp voltage which is compared with the magnitude of the received signal by a comparator. The microprocessor measures the time it takes the ramp voltage to rise to the magnitude of the detected signal. The microprocessor continuously computes a recursive short term average and compares this average value with a recursive long-term average. Deviations between the two time periods are the result of a disturbance within the monitoring field. Furthermore, the system is continuously self-adjusted to allow the conversion process to occur within the bounds of the measurement circuit, by changing the gain applied to the detected signal.