Patents Assigned to Daniel A. Tardiff
  • Patent number: 4021679
    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.
    Type: Grant
    Filed: October 22, 1975
    Date of Patent: May 3, 1977
    Assignees: Fred Bolle, Chen Yi Lee, Daniel A. Tardiff
    Inventors: Fred Bolle, Chen Yi Lee, Daniel A. Tardiff