Telephone battery feed circuit

Claim 2

A battery feed circuit for connection by telephone switching equipment to a telephone set for providing power thereto and for detecting supervisory signals therefrom, said battery feed comprising: a first pair of terminals for connection to a direct current power supply; a second pair of terminals for connection to the telephone switching equipment; a semiconductor device including an input circuit having a radiation source that generates photon radiation, the intensity of which is a function of current flow therethrough, and an output circuit having a radiation sensitive device, the impedance of which is a function of the intensity of the radiation from said source, said input and output circuit being electrically isolated; impedance means, having a direct current path therethrough, and exhibiting a substantially higher impedance to audio frequency current than to direct current, for blocking audio current to said first pair of terminals; direct current circuit means for connecting said first pair of terminals to said second pair of terminals through said impedance means to provide a direct current path therebetween, and said input circuit being connected between said impedance means and said first pair of terminals so that said semiconductor device provides signals indicating the conductive and nonconductive conditions of said direct current path.

Claim 3

A battery feed circuit as defined in claim 1 wherein: said direct current circuit means includes first and second resistance means connected in series with each other and said direct current path and connected to one of said first pair of terminals; the input circuit of said semiconductor device is connected between the junction of said first and second resistance means and the one of said first pair of terminals connected thereto, and said direct current circuit means includes a third resistance means connected in series with said direct current path and the other one of said first terminal pair.

Claim 4

A battery feed circuit as defined in claim 1 including: timing circuit means connected to receive signals from said semiconductor device for distinguishing transient signals from supervisory signals.

Claim 5

A battery feed circuit as defined in claim 3 wherein: said timing circuit means includes counting circuit means for distinguishing between dial, hook flash, off hook, and on hook type supervisory signals.

Claim 6

A battery feed circuit as defined in claim 2 wherein: said radiation source is a light emitting diode, and said radiation sensitive device is a light sensitive transistor.

Claim 7

A battery feed circuit for applying power from a direct current power supply to a telephone set connected thereto by telephone switching equipment, and for detecting supervisory signals, said battery feed circuit comprising: an impedance coil able to pass direct current and substantially block audio frequency current therethrough; direct current circuit means for providing a direct current path between the power supply and the telephone switching equipment through said impedance coil; an optoelectronic coupler; circuit means connecting said optoelectronic coupler to said direct current path between said coil and said power supply so taht said optoelectronic coupler provides signals indicating the conductive and nonconductive conditions of said direct current path, and timing circuit means connected to said optoelectronic coupler for distinguishing between dial, on hook, off hook, hook flash signals, and for rejecting transient signals.

Claim 8

A battery feed circuit for applying power from a direct current power supply to a telephone set connected thereto by telephone switching equipment, and for detecting supervisory signals, said battery feed circuit comprising: an impedance coil able to pass direct current and substantially block audio frequency current therethrough; direct current circuit means for providing a direct current path between the power supply and the telephone switching equipment through said impedance coil; an optoelectronic coupler; circuit means connecting said optoelectronic coupler to said direct current path between said coil and said power supply so taht said optoelectronic coupler provides signals indicating the conductive and nonconductive conditions of said direct current path, and timing circuit means connected to said optoelectronic coupler for distinguishing between dial, on hook, off hook, hook flash signals, and for rejecting transient signals.

Claim 9

A battery feed circuit as defined in claim 6 wherein: said optoelectronic coupler connection circuit means connects the optoelectronic coupler to said direct current path so that said optoelectronic coupler is conductive when the direct current path is in a conductive condition.

Claim 10

A battery feed circuit for connection by telephone switching equipment to a telephone set for providing power thereto and for deTecting supervisory signals therefrom, said battery feed comprising: a first pair of terminals for connection to a direct current power supply; a second pair of terminals for connection to the telephone switching equipment; a semiconductor device including an input circuit having a radiation source that generates photon radiation, the intensity of which is a function of current flow therethrough, and an output circuit having a radiation sensitive device, the impedance of which is a function of the intensity of the radiation from said source, said input and output circuit being electrically isolated; impedance means, having a direct current path therethrough and exhibiting a substantially higher impedance to audio frequency current than to direct current, for blocking audio current to said first pair of terminals; direct current circuit means for connecting said first pair of terminals to said second pair of terminals through said impedance means to provide a direct current path therebetween; said input circuit being connected between said impedance means and said first pair of terminals so that said semiconductor device provides signals indicating the conductive and nonconductive conditions of said direct current path; timing circuit means connected to receive signals from said semiconductor device for distinguishing transient signals from supervisory signals; said timing circuit means includes counting circuit means for distinguishing between dial, hook flash, off hook, and on hook type supervisory signals; a lockup counter circuit for determining when the semiconductor device has been conductive for a sufficient period of time to indicate an off hook condition and provides a continuous signal thereafter until released, and a counting circuit, responsive to said continuous signal, for determining the period of time the semiconductor device is nonconductive thereafter, to differentiate between dial, hook flash, on hook and off hook type supervisory signals.

Claim 11

A battery feed circuit for connection by telephone switching equipment to a telephone set for providing power thereto and for deTecting supervisory signals therefrom, said battery feed comprising: a first pair of terminals for connection to a direct current power supply; a second pair of terminals for connection to the telephone switching equipment; a semiconductor device including an input circuit having a radiation source that generates photon radiation, the intensity of which is a function of current flow therethrough, and an output circuit having a radiation sensitive device, the impedance of which is a function of the intensity of the radiation from said source, said input and output circuit being electrically isolated; impedance means, having a direct current path therethrough and exhibiting a substantially higher impedance to audio frequency current than to direct current, for blocking audio current to said first pair of terminals; direct current circuit means for connecting said first pair of terminals to said second pair of terminals through said impedance means to provide a direct current path therebetween; said input circuit being connected between said impedance means and said first pair of terminals so that said semiconductor device provides signals indicating the conductive and nonconductive conditions of said direct current path; timing circuit means connected to receive signals from said semiconductor device for distinguishing transient signals from supervisory signals; said timing circuit means includes counting circuit means for distinguishing between dial, hook flash, off hook, and on hook type supervisory signals; a lockup counter circuit for determining when the semiconductor device has been conductive for a sufficient period of time to indicate an off hook condition and provides a continuous signal thereafter until released, and a counting circuit, responsive to said continuous signal, for determining the period of time the semiconductor device is nonconductive thereafter, to differentiate between dial, hook flash, on hook and off hook type supervisory signals.

Claim 12

A battery feed circuit as defined in claim 8 wherein said counting circuit means includes: circuit means responsive to the dial signals from said counter circuit for repeating the dial signals, and circuit means responsive to an end of dial signal for inhibiting said dial signal repeating circuit means.

Claim 13

A battery feed circuit for applying power from a direct current power supply to a telephone set connected thereto by telephone switching equipment, and for detecting supervisory signals, said battery feed circuit comprising: an impedance coil able to pass direct current and substantially block audio frequency current therethrough; direct current circuit means for providing a direct current path between the power supply and the telephone switching equipment through said impedance coil; an optoelectronic coupler; circuit means connecting said optoelectronic coupler to said direct current path between said coil and said power supply so that said optoelectronic coupler provides signals indicating the conductive and nonconductive conditions of said direct current path; said optoelectronic coupler connection circuit means connects the optoelectronic coupler to said direct current path so that said optoelectronic coupler is conductive when direct current path is in a conductive condition; a lockup counter circuit for determining when said optoelectronic coupler has been rendered conductive for a sufficient period of time to indicate an initial off hook condition and provides the continuous signal thereafter until released by an on hook signal, and counting circuit means responsive to said continuous signal, for determining the period of time said optoelectronic coupler is nonconductive thereafter, to differentiate between dial, hook flash, on hook and off hook supervisory signals.

Claim 14

A battery feed circuit for applying power from a direct current power supply to a telephone set connected thereto by telephone switching equipment, and for detecting supervisory signals, said battery feed circuit comprising: an impedance coil able to pass direct current and substantially block audio frequency current therethrough; direct current circuit means for providing a direct current path between the power supply and the telephone switching equipment through said impedance coil; an optoelectronic coupler; circuit means connecting said optoelectronic coupler to said direct current path between said coil and said power supply so that said optoelectronic coupler provides signals indicating the conductive and nonconductive conditions of said direct current path; said optoelectronic coupler connection circuit means connects the optoelectronic coupler to said direct current path so that said optoelectronic coupler is conductive when direct current path is in a conductive condition; a lockup counter circuit for determining when said optoelectronic coupler has been rendered conductive for a sufficient period of time to indicate an initial off hook condition and provides the continuous signal thereafter until released by an on hook signal, and counting circuit means responsive to said continuous signal, for determining the period of time said optoelectronic coupler is nonconductive thereafter, to differentiate between dial, hook flash, on hook and off hook supervisory signals.

Claim 15

A battery feed circuit for connection by telephone equipment to a telephone set for providing power thereto and for detecting supervisory signals therefrom, said battery feed comprising: a first pair of terminals for connection to a direct current power supply; a second pair of terminals for connection to the telephone switching equipment; a semiconductor device including an input circuit having a radiation source that generates photon radiation, the intensity of which is a function of current flow therethrough, and an output circuit having a radiation sensitive device, the impedance of which is a function of the intensity of the radiation from said source, said input and output circuit being electrically isolated; impedance means, having a direct current path therethrough, and exhibiting a substantially higher impedance to audio frequency current than to direct current, for blocking audio current to said first pair of terminals; direct current circuit means for connecting said first pair of terminals to said second pair of terminals through said impedance means to provide a direct current path therebetween; said input circuit being connected between said impedance means and said first pair of terminals so that said semiconductor device provides signals indicating the conductive and nonconductive conditions of said direct current path; said direct current circuit means includes first and second resistance means connected in series with each other and said direct current path and connected to one of said first pair of terminals; the input circuit of said semiconductor device is connected between the junction of said first and second resistance means and the one of said first pair of terminals connected thereto; said direct current circuit means includes a third resistance means connected in series with said direct current path and the other one of said first terminal pair; said input circuit includes fourth resistance means connected in series with said radiation device, and wherein the resistance value of the connection including the first resistance means and the parallel combination of the second and fourth resistance means is substantially equal to the resistance value of the third resistance means.

Claim 16

A battery feed circuit for connection by telephone equipment to a telephone set for providing power thereto and for detecting supervisory signals therefrom, said battery feed comprising: a first pair of terminals for connection to a direct current power supply; a second pair of terminals for connection to the telephone switching equipment; a semiconductor device including an input circuit having a radiation source that generates photon radiation, the intensity of which is a function of current flow therethrough, and an output circuit having a radiation sensitive device, the impedance of which is a function of the intensity of the radiation from said source, said input and output circuit being electrically isolated; impedance means, having a direct current path therethrough, and exhibiting a substantially higher impedance to audio frequency current than to direct current, for blocking audio current to said first pair of terminals; direct current circuit means for connecting said first pair of terminals to said second pair of terminals through said impedance means to provide a direct current path therebetween; said input circuit being connected between said impedance means and said first pair of terminals so that said semiconductor device provides signals indicating the conductive and nonconductive conditions of said direct current path; said direct current circuit means includes first and second resistance means connected in series with each other and said direct current path and connected to one of said first pair of terminals; the input circuit of said semiconductor device is connected between the junction of said first and second resistance means and the one of said first pair of terminals connected thereto; said direct current circuit means includes a third resistance means connected in series with said direct current path and the other one of said first terminal pair; said input circuit includes fourth resistance means connected in series with said radiation device, and wherein the resistance value of the connection including the first resistance means and the parallel combination of the second and fourth resistance means is substantially equal to the resistance value of the third resistance means.