Ring trip circuit

Claim 2

A telephone ring trip circuit for connection in a series circuit with a telephone line, a ringing generator for applying AC ringing signals to the telephone line, and a battery, said ring trip circuit comprising: an input terminal for connecting said ring trip circuit to said ringing generator and said battery; an output terminal for connecting said ring trip circuit to said telephone line; first unidirectional current conductive circuit means connected between said input and output terminals; a second unidirectional current conductive circuit means connected between said input and output terminals poled for current flow in the opposite direction of said first unidirectional circuit means, said second unidirectional circuit means including capacitive means connected for charging by ringing signal and direct current flow wherein said capacitive means is charged to a higher potential with both ringing signal and direct current flow than with ringing signal current flow alone, and switching circuit means connected to said capacitive means and responsive to the higher potential across said capacitive means for providing an output signal for tripping the ringing generator.

Claim 3

A ring trip circuit as defined in claim 1 wherein: said second unidirectional current conductive cIrcuit means includes first and second semiconductor devices, resistive means, capacitive means connected in parallel with said first semiconductor device, and circuit means for connecting said first semiconductor device and said resistive and capacitive means between said input and output terminals so that with a first polarity of signal across said terminals said capacitive means is charged through said resistive means, and with the reverse polarity of signal across said terminals said capacitive means is discharged through said first semiconductor device, and wherein said switching circuit means includes a switching device and circuit means for connecting said second semiconductor device to said capacitive means, said second semiconductor device being responsive to said higher potential to actuate said switching device.

Claim 4

A telephone ring trip circuit for connection in a series circuit with a telephone line, a ringing signal generator for applying AC ringing signals to the telephone line and a battery, said ring trip circuit comprising: an input terminal for connecting said ring trip circuit to said ringing generator and said battery; an output terminal for connecting said ring trip circuit to said telephone line; a switching device to provide a trip signal when actuated; first and second unidirectional current conductive circuit means connected between said input and output terminals and poled for current flow in opposite directions, each of said first and second unidirectional current conductive circuit means including capacitive means connected for charging by ringing signal and direct current flow, wherein each said capacitive means is charged to a higher potential with both ringing signal and direct current flow than with ringing signal current flow alone, and circuit means connecting the capacitive means of said first and second unidirectional current conductive circuit means to said switching device so that said switching device is actuated in response to the higher potential across said capacitive means.

Claim 5

A telephone ring trip circuit for connection in a series circuit with a telephone line, a ringing signal generator for applying AC ringing signals to the telephone line and a battery, said ring trip circuit comprising: an input terminal for connecting said ring trip circuit to said ringing generator and said battery; an output terminal for connecting said ring trip circuit to said telephone line; a switching device to provide a trip signal when actuated; first and second unidirectional current conductive circuit means connected between said input and output terminals and poled for current flow in opposite directions, each of said first and second unidirectional current conductive circuit means including capacitive means connected for charging by ringing signal and direct current flow, wherein each said capacitive means is charged to a higher potential with both ringing signal and direct current flow than with ringing signal current flow alone, and circuit means connecting the capacitive means of said first and second unidirectional current conductive circuit means to said switching device so that said switching device is actuated in response to the higher potential across said capacitive means.

Claim 6

A ring trip circuit as defined in claim 1 wherein: each of said first and second unidirectional conductive circuits includes first and second semiconductor devices, resistive means, capacitive means connected in parallel with said first semiconductor device, circuit means for connecting said first semiconductor device and said resistive and capacitive means between said input and output terminals so that with a first polarity of signal across said terminals said capacitive means is charged through said resistive means, and with the reverse polarity of signal across said terminals said capacitive means is discharged through said first semiconductor device, and circuit means for connecting said second semiconductor device so that its conduction is responsive to the charge on said capacitive means, and wherein said circuit means for connecting said first and second unidirectional current conductive circuit means to said switching device connects said second semiconductor device to actuate said switching device in response to said higher potential.

Claim 7

In a telephone system including a power source providing direct current potential and AC ringing signals, switching equipment, and a ring trip circuit for applying direct current and ringing signals to telephone lines via switching equipment, said ring trip circuit comprising: a first terminal for connection to the switching equipment; a second terminal for connection to said power source; a first unidirectional current conductive circuit connected between said first and second terminals, and a second unidirectional current conductive circuit connected between said first and second terminals poled for current conduction in a direction opposite said first unidirectional current conductive circuit, said second unidirectional current conductive circuit including a resistance-capacitance charging circuit means for charging to a first potential level in response to ringing signal current flow and to a second potential level higher than said first potential level in response to both ringing signal current and direct current flow, and circuit means connected to said resistance-capacitance circuit means responsive to said second potential level to provide an output signal indicating an off-hook condition.

Claim 8

In a telephone system including a power source providing direct current potential and AC ringing signals, switching equipment, and a ring trip circuit for applying direct current and ringing signals to telephone lines via switching equipment, said ring trip circuit comprising: a first terminal for connection to the switching equipment; a second terminal for connection to said power source; a first unidirectional current conductive circuit connected between said first and second terminals, and a second unidirectional current conductive circuit connected between said first and second terminals poled for current conduction in a direction opposite said first unidirectional current conductive circuit, said second unidirectional current conductive circuit including a resistance-capacitance charging circuit means for charging to a first potential level in response to ringing signal current flow and to a second potential level higher than said first potential level in response to both ringing signal current and direct current flow, and circuit means connected to said resistance-capacitance circuit means responsive to said second potential level to provide an output signal indicating an off-hook condition.

Claim 9

A ring trip circuit as defined in claim 5 wherein said unidirectional current conductive circuit includes: first and second semiconductor devices; resistive means; capacitive means; switching means; circuit means for connecting a first one of said semiconductor devices and said resistive and capacitive means between said pair of terminals so that with a first polarity of signal across said terminals said capacitive means is charged through said resistive means, and with the reverse polarity of signal across said terminals said capacitive means is discharge through said first semiconductor device, and circuit means for connecting said second semiconductor device to said capacitive means so that said second semiconductor device is responsive to said second potential to actuate said switching means.

Claim 10

A ring trip circuit as defined in claim 5 wherein said first unidirectional current conductive circuit comprises a diode.

Claim 11

A ring trip circuit as defined in claim 6 wherein said first unidirectional current conductive circuit includes a diode, and wherein said circuit means connecting said first semiconductor device and said circuit means connecting said second semiconductor device includes a diode connected in series therewith.

Claim 12

A ring trip circuit as defined in claim 6 wherein said first unidirectional current conductive circuit includes a resistance-capacitance charging circuit means for charging to a first potential level in response to ringing signal current flow and to a second potential higher than said first potential in response to both ringing signal current and direct current flow, and circuit means connected to said resistance-capacitance circuit means responsive to said second potential to provide an output signal indicating an off hook condition.