Method and apparatus for automatic switching
First Claim
1. In the method for controlling a two-state switching means to regulate the artificial light in an area and including a capacitance comparison circuit having two branches normally capacitively imbalanced in a first direction, one branch of said capacitive comparison circuit including a metallic sheet, and including generating input signals to said capacitive comparison circuit, the improvement comprising:
- changing the capacitance of said one branch of the capacitance comparison circuit by moving at least a portion of the human body into contactless proximity of the sheet;
converting said input signals into triggering signals when the capacitance in said one branch of said capacitance comparison circuit exceeds the capacitance in said other branch;
switching the two-state switching means in response to said triggering signals only when the magnitude of said triggering signals exceed a predetermined threshold; and
continuously monitoring the level of existing light in said area and changing said predetermined threshold between a first level and second level, depending upon the level of existing light in said area.
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Accused Products
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.
53 Citations
12 Claims
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1. In the method for controlling a two-state switching means to regulate the artificial light in an area and including a capacitance comparison circuit having two branches normally capacitively imbalanced in a first direction, one branch of said capacitive comparison circuit including a metallic sheet, and including generating input signals to said capacitive comparison circuit, the improvement comprising:
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changing the capacitance of said one branch of the capacitance comparison circuit by moving at least a portion of the human body into contactless proximity of the sheet; converting said input signals into triggering signals when the capacitance in said one branch of said capacitance comparison circuit exceeds the capacitance in said other branch; switching the two-state switching means in response to said triggering signals only when the magnitude of said triggering signals exceed a predetermined threshold; and continuously monitoring the level of existing light in said area and changing said predetermined threshold between a first level and second level, depending upon the level of existing light in said area. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In a method for controlling a two-state switching means to regulate the artificial light in an area and including generating ultrasonic signals in said area, receiving reflected ultrasonic signals, and detecting the magnitude of output signals, the improvement comprising:
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moving at least a portion of the human body into said area to reflect the ultrasonic signals; receiving the reflected ultrasonic signals and converting the reflected signals into output signals; switching said two-state switching means into a first state to turn on the artificial light only when the magnitude of the output signals exceeds a predetermined threshold, and continuously monitoring the level of existing light in said area and changing said predetermined threshold between a first level and a second level, depending upon the level of existing light in said area.
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8. In an apparatus for controlling a two-state switching means to regulate artificial light in an area and including an oscillator to generate ultrasonic signals and a receiver to receive the ultrasonic signals and to detect reflected ultrasonic signals, the improvement comprising a dual sensitivity threshold detector for detecting the magnitude of the output from said receiver and for generating a triggering signal to control the artificial light in the area;
- photoresponsive means for detecting the magnitude of illumination in the area and for generating an output signal in response thereto to control the threshold detector means;
said photoresponsive means to establish first and second threshold levels based upon the level of illumination in the area, andsaid dual sensitivity threshold detector for generating said triggering signals to permit the artificial light to be turned on only if the magnitude of the reflected ultrasonic signals exceeds the threshold level established by the photoresponsive means. - View Dependent Claims (9, 10, 11, 12)
- photoresponsive means for detecting the magnitude of illumination in the area and for generating an output signal in response thereto to control the threshold detector means;
Specification