Private automatic branch exchange system and apparatus
First Claim
1. Apparatus for selectively coupling a telephone central office circuit to subscriber equipment, comprising:
- first solid state means having a control circuit which is operatively coupled to said central office circuit and responsive to a ringing signal on said central office circuit to provide a signal on a ring detection circuit which is electrically isolated from said central office circuit;
switch means connected to said central office circuit and selectively operative to complete a circuit interconnection between the central office circuit and a subscriber circuit;
second solid state means having a control circuit which can receive a line pickup signal which is electrically isolated from said central office circuit and which is operative in response to said line pickup signal to control said switch means to complete said circuit; and
third solid state means having a control circuit which is connected to be responsive to current flow through said central office circuit and through said switch means to provide an output signal on a line pickup acknowledge circuit which is electrically isolated from said central office circuit.
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Accused Products
Abstract
A private automatic branch telephone exchange system which includes an integral system for maintaining and updating selected data information. Interconnections between subscriber lines and trunk lines are accomplished with a unique non-blocking switching matrix which allows switching interconnections to be independently made and terminated without blocking subsequent interconnections on the same circuits. Various information signal functions, such as dial tone and ring-back, are selected by multiplex circuitry which is external of the switching matrix, so that all switching matrix trunks are available for voice and ring signal connections. The switching matrix is operated by a circuitry including a programmed digital computer, and provides substantial flexibility of control and service functions. Subscriber line status is monitored at all times, so that available special services can be accomplished by a subscriber in response to dialing selected digits. A novel coupler circuit is disclosed for interconnecting the present or another branch exchange system to central office lines. Subscriber dialing of a predetermined non-interconnect code allows a subscriber to dial updating input data directly to a memory storage means.
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Citations
16 Claims
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1. Apparatus for selectively coupling a telephone central office circuit to subscriber equipment, comprising:
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first solid state means having a control circuit which is operatively coupled to said central office circuit and responsive to a ringing signal on said central office circuit to provide a signal on a ring detection circuit which is electrically isolated from said central office circuit; switch means connected to said central office circuit and selectively operative to complete a circuit interconnection between the central office circuit and a subscriber circuit; second solid state means having a control circuit which can receive a line pickup signal which is electrically isolated from said central office circuit and which is operative in response to said line pickup signal to control said switch means to complete said circuit; and third solid state means having a control circuit which is connected to be responsive to current flow through said central office circuit and through said switch means to provide an output signal on a line pickup acknowledge circuit which is electrically isolated from said central office circuit. - View Dependent Claims (2, 3, 4, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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5. said bridge circuit being polarized to block current flow directly therethrough and being operative to permit current flow through a path which includes a pair of points on said bridge circuit and an external circuit connected between said bridge points;
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said control circuit of said second solid-state means comprises photoisolator means having a light-emitting means operative in response to said line pickup signal, and having a photo-responsive means connected in said external circuit and operative to complete a conductive path through said bridge circuit in response to said light-emitting means.
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7. An addressable N ×
- M switching matrix, comprising;
a first number M of subscriber lines in parallel matrix array, each subscriber line comprising at least a pair of conductors for connection with a separate subscriber station; a second number N of trunk lines in parallel matrix array with each other and in crossing relation with each of said subscriber lines, each of said trunk lines comprising at least a pair of conductors; switching means separately and independently associated with each crossing point of subscriber lines and trunk lines in said matrix, each said switching means being selectively operative to connect a subscriber line to the trunk line at such crossing point; and a number M of addressable switch actuating means; one of said addressable switch actuating means being operatively associated with all of said switching means for said crossing points of a particular subscriber line, with each said addressable switch actuating means being operative to enable any of said associated switch means in response to a predetermined enabling input signal to said addressable switch actuating means, whereby a portion of the particular subscriber line and the subscriber station connected to said portion become connected to a selected said trunk line at the matrix crossing point controlled by said selected switching means and become disconnected from the remaining extent of such subscriber line across said matrix, and being operative to disenable all such associated switching means in response to a reset input signal to said addressable switch actuating means, whereby any existing previous said selected trunk line connection is terminated and said subscriber line uninterruptedly crosses said trunk lines without connection thereto.
- M switching matrix, comprising;
Specification