Two-line apparatus for telephone intercom

• US 5,781,622 A
• Filed: 05/05/1995
• Issued: 07/14/1998
• Est. Priority Date: 04/08/1990
• Status: Expired due to Fees

• Current Assignee: Kornizer Ben-Zion
• Original Assignee: Kornizer Ben-Zion
• Inventors: Ben-Zion, Kornizer
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): LOOMIS, PAUL A
• Application Number:
  US08/435,562
• Time in Patent Office: 1,166 Days
• Field of Search: 379/102, 379/159, 379/103, 379/160, 379/167-187, 379/199, 379/200, 379/372, 379/373, 379/375
• US Class Current: 379/159
• CPC Class Codes: H04M 1/715 using two or more extensions per line cordless telephones H04M1/725
• CPC Class Codes: H04M 9/02 involving a common line for all parties

Abstract

An apparatus for providing an intercom function on a telephone, without the need for an external power supply, having DTMF or pulse capabilities including an intercom operation device arranged for connection to a DTMF or pulse telephone line and to a DTMF or pulse telephone instrument. The apparatus includes a device for sensing an extension selection dual input from the DTMF or pulse telephone instrument and transmitting a corresponding extension address signal over the DTMF or pulse telephone line. Also included is an apparatus for sensing a received extension address signal from the telephone line, determining whether it corresponds to the telephone instrument to which the intercom operation apparatus is connected and, upon determination of correspondence, providing an extension selection ring output.

Claims

1. Apparatus for providing an intercom function on a telephone having DTMF or pulse capabilities including at least one intercom operation device arranged for connection to a DTMF or pulse telephone line and to a DTMF and pulse telephone instrument and comprising:

means for sensing a received extension address signal along the telephone line, determining whether the address corresponds to the telephone instrument to which the intercom operation apparatus is connected and, upon determination of correspondence, providing an extension selection ring output, and an internal power supply wherein said power supply uses only the telephone line voltage;

an internal DTMF receiver circuit unit, an internal pulse receiver and an identification integrated circuit unit and a buzzer; and

wherein the internal power supply unit provides 3-5 volts to the system and 2.5-3 milliampere during operation.

2. Apparatus for providing an intercom function on a telephone having DTMF or pulse capabilities including at least one intercom operation device arranged for connection to a DTMF or pulse telephone line and to a DTMF and pulse telephone instrument and comprising:

means for sensing a received extension address signal along the telephone line, determining whether the address corresponds to the telephone instrument to which the intercom operation apparatus is connected and, upon determination of correspondence, providing an extension selection ring output, and an internal power supply wherein said power supply uses only the telephone line voltage;

further comprising an internal power supply unit using the telephone line voltage, internal DTMF receiver circuit unit, internal pulse receiver and identification integrated circuit unit and a buzzer,

wherein the internal power supply unit provides current to the system only when the telephone line voltage is between 17 V and 5 V.

3. Apparatus according to claim 2, wherein the internal power supply unit operates automatically when the telephone line voltage drops below 17 V.

4. Apparatus according to claim 2, wherein the internal power supply unit stops to operate automatically when the telephone line voltage drops below 5 V.