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Phone screen security system

  • US 4,860,347 A
  • Filed: 08/10/1988
  • Issued: 08/22/1989
  • Est. Priority Date: 08/10/1988
  • Status: Expired due to Fees
First Claim
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1. A phone screen security system for blocking unwanted incoming phone calls and unauthorized outgoing phone calls, comprising:

  • a housing;

    outside connection means in said housing for connection with an outside phone line;

    pick up circuit means in said housing for detecting a ring signal on said outside phone line;

    voice synthesizer means in said housing for requesting a security code input from a caller on said outside phone line;

    relay means actuated by said pick up circuit means for connecting said voice synthesizer means to said outside phone line;

    programmable code detect means for comparing a tone signal from said outside phone line with a programmed security code;

    said code detect means actuated by said voice synthesizer means;

    timing circuit means connected to said code detect means and said pick up circuit means for disconnecting said outside phone line after a predetermined time interval if a correct security code is not detected;

    said code detect means actuating said voice synthesizer means to inform a caller of a correct security code input;

    line select relay means connected to a plurality of inside phone lines;

    relay means activated by said code detect means for connecting said outside phone line to said line select relay means;

    ringer means for sending a ring signal to one of said plurality of said inside phone lines;

    a power connection on said housing for connection with a conventional source of 120 VAC;

    transformer means in said housing for reducing said 120 VAC to 48 VAC;

    power supply means in said housing for dividing said 48 VAC into 24 VDC supply to said line select relay means and 96 VAC to said ringer means;

    a four position switch connected to said line select relay means;

    said switch having an OFF position in which said inside phone lines are connected to said outside phone lines;

    said switch having an AUTO position in which said inside phone lines are connected to said pick up circuit means and bypass said code detect means;

    said switch having a CODE position in which said inside phone lines are connected to said code detect means and a correct security code must be input to access said outside phone line; and

    said switch having a PROGRAM position which connects said inside phone lines for programming respective security codes into said programmable code detect means.

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