×

Method for remote power fail detection and maintaining continuous operation for data and voice devices operating over local loops

  • US 5,216,704 A
  • Filed: 06/12/1991
  • Issued: 06/01/1993
  • Est. Priority Date: 06/12/1991
  • Status: Expired due to Term
First Claim
Patent Images

1. An improved system for maintaining voice communications in a voice and data communications system, said system comprising:

  • first and second voice and data modem means disposed at a subscriber location and a central office location, respectively, wherein each of said respective voice and data modem means include voice and data input means and output means;

    first and second transformer means for coupling the output means of said respective first and second modem means to telephone lines, said first and second transformer means each including a winding having a centertap terminal, the centertap terminal of said first transformer means being split and coupled to a sealing current source and the centertap terminal of said second transformer means being coupled to ground;

    means for detecting a power failure at said subscriber location; and

    ,means for bypassing said first and second voice and data modem means and said first and second transformer means upon detecting power failure at said subscriber location.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×