VOICE-MONITORING CONTROL CIRCUIT

• US 3,798,382 A
• Filed: 05/22/1972
• Issued: 03/19/1974
• Est. Priority Date: 05/22/1972
• Status: Expired due to Term

• Current Assignee: Code-A-Phone Corp.
• Original Assignee: El Don L. Hoven
• Inventors: Hoven, El Don L.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Faber, Alan
• Application Number:
  US05/255,730
• Time in Patent Office: 666 Days
• Field of Search: 179/81R,84C,84L,88,89,7.1R,2TC,18BE,170.2,170.6,170.8,6R,6C,6E,1VC
• US Class Current: 379/157
• CPC Class Codes: H04M 1/654 Telephone line monitoring circuits therefor, e.g. ring detectors
• CPC Class Codes: H04M 1/82 Line monitoring circuits for call progress or status discrimination for detecting caller identity H04M1/573

Abstract

A circuit for assuring automatic breaking of a talking connection in a telephone line a preselected time interval after talking has ceased on the line. The circuit has particular ultility in connection with apparatus such as a call diverter, or a telephone answering and message-recording device. The circuit includes a digital-type counting circuit which is fed pulses to be counted, and which effects breaking of a talking connection on reaching a certain count. A frequency-sensitive circuit responsive to a limited range of voice frequencies (found to recur frequently in normal male and female conversation) monitors voice frequencies on the line, and on sensing a frequency within such range, effects resetting of the counting circuit to a zerocount condition to prevent breaking of a talking connection.

Claims

1. A voice-monitoring control circuit for use in combination with electrical switch means connected to a telephone line, where the switch means when closed establishes a talking connection in the line, and when opened breaks such a connection, said control circuit in operative condition comprising a supply of regularly recurring electrical pulses, an electronic digital counting circuit operatively connected to said supply and to said switch means for counting pulses supplied by the former and for effecting, when said switch means is closed, opening thereof on the count of such pulses reaching a predetermined count, said counting circuit being constructed for instantaneous, direct resetting to a zero-count condition from any above-zero count condition, and a frequency-sensitive circuit responsive to a narrow band of voice audio frequencies and operatively connected to said telephone line and to said counting circuit, said frequencysensitive circuit effecting instantaneous, direct resetting of said counting circuit to a zero-count condition on each different occurrence in said telephone line, with a talking connection existing therein, of a voice audio frequency within said band.

2. The control circuit of claim 1 which further comprises a tone generator operatively connected to said counting circuit and to said telephone line, operable to place a tone on the latter on the count in the former reaching another predetermined count which is less than said first-mentioned predetermined count.

3. A voice-monitoring control circuit for use in combination with apparatus for diverting a call from a first telephone line to a second telephone line, where there is an electrical switch means connected to at least one of said lines which when closed establishes a talking connection in such line, and when opened breaks such a connection, said control circuit in operative condition comprising a supply of regularly recurring electrical pulses, an electronic digital counting circuit operatively connected to said supply and to said switch means for counting pulses supplied by the former and for effecting, when said switch means is closed, opening thereof on the count of such pulses reaching a predetermined count, said counting circuit being constructed for instantaneous, direct resetting to a zero-count condition from any above-zero count condition, and a frequency-sensitive circuit responsive to a narrow band of voice audio frequencies and operatively connected to both of said telephone lines and to said counting circuit, said frequency-sensitive circuit effecting instantaneous, direct resetting of said counting circuit to a zero-count condition on each different occurrence in either of said lines, with a talking connection existing in said one line, of a voice audio frequency within said band.

4. The control circuit of claim 3, wherein said switch means is connected to said first telephone line.

5. The control circuit of claim 3 which further comprises a tone generator operatively connected to said counting circuit and to said telephone lines, operable to place a tone on each of the latter on the count in the former reaching another predetermined count which is less than said first-mentioned predetermined count.