×

Battery-operated receiver for wireless audible indication system

  • US 5,757,267 A
  • Filed: 12/12/1995
  • Issued: 05/26/1998
  • Est. Priority Date: 07/29/1994
  • Status: Expired due to Fees
First Claim
Patent Images

1. A receiver for use in an audible indication system with a corresponding transmitter which transmits a radio frequency signal, the receiver powered by a battery source, the receiver comprising:

  • a radio frequency detector which produces a first signal upon receiving the radio frequency signal from the corresponding transmitter;

    a signal processing circuit, coupled to the radio frequency detector, which processes the first signal to form a second signal, wherein the signal processing circuit includes a CMOS device which contains a plurality of MOS field effect transistors having a threshold voltage; and

    a sound generator, coupled to the signal processing circuit, which generates an audible indication when the second signal is indicative of reception of the radio frequency signal;

    wherein the CMOS device is powered at a first voltage near to the threshold voltage of the MOS field effect transistors in the CMOS device.

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