Patents Examined by Deu V. Le
  • Patent number: 5077484
    Abstract: A light level controlled electrical extension socket comprising a main body on which is formed two pairs of insertion sockets for receiving an appliance's power plug, a photosensitive element externally mounted in a housing on the main body, an extension cord attached to a power outlet, and a pair of indicator lights for each respective pair of insertion sockets. Each insertion socket comprises three receiving slots, whereby, a power plug inserted to the right side always receives power as in a convention adapter. A power plug inserted to the left side has its power turned on or off automatically according to prevailing light levels. A first pair of insertion sockets has its power on in automatic mode, i.e. the left side when the second pair has its power turned off, and vice versa. The indicator lights for each corresponding pair of insertion sockets reflect the status of each respective pair.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: December 31, 1991
    Inventors: Shiang Shiun Tsai, Ming Jeng Tsai