Electrical controller having a window discriminator

• US 4,618,770 A
• Filed: 03/21/1985
• Issued: 10/21/1986
• Est. Priority Date: 03/21/1985
• Status: Expired due to Term

• Current Assignee: Phillips Communciation & Security
• Original Assignee: RCA Corporation (General Electric Company)
• Inventors: Maile, Donald W.
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US06/714,510
• Time in Patent Office: 579 Days
• Field of Search: 250/342, 250/338 R, 340/567, 361/173, 361/175, 307/360
• US Class Current: 250/338.1
• CPC Class Codes: G08B 13/19 using infrared-radiation detection systems G08B13/194 takes precedence
• CPC Class Codes: Y10S 250/01 Passive intrusion detectors

Abstract

An electrical control has a detector which senses the infrared radiation within a given area. A pair of comparators function as a window discriminator. A voltage divider provides reference bias potentials to the comparators. The same divider provides a bias to the signal input terminals of the comparators. These signal input terminals are coupled through a capacitor to the detector. The output of the comparators is used to actuate the control.

Claims

1. In a device for controlling the flow of electricity wherein the device includes means for detecting infrared radiation within a given area, the improvement comprising of a window discriminator including:

a voltage divider having three nodes for providing three different voltage potentials, said potentials being relatively and respectively high, intermediate and low;

a first comparator having a noninverting input terminal connected to the node of high voltage potential and an inverting input terminal coupled to the output of said infrared radiation detecting means;

a second comparator having an inverting input terminal connected to the node of low voltage potential and a noninverting input terminal coupled to the output of said infrared radiation detecting means;

means for coupling the node of intermediate potential to both the inverting input terminal of the first comparator and the noninverting input terminal of the second comparator; and

means responsive to the outputs of the comparators for actuating the control of electricity.

2. The device as in claim 1 wherein the node coupling means comprises a resistor.

3. The device as in claim 1 further comprising a capacitor coupling the output of the detecting means to both the inverting input terminal of the first comparator and the noninverting input terminal of the second comparator.