Itec Corporation

Southwestern Bell Telephone

Sace, Incorporated

Roger F Atkinson

Arthur O Miller

William D Welch, Jr

Ronald L Jolly

Boyd Dorsey

Steven C Dennison

Hollis Coleman

A method of providing equal access to a number of long distance carriers in local telephone company office containing No. 5 crossbar switching machines. Calls are intercepted between the line link frame and the originating registers. If the call is a long distance call, a serial number which resembles a conventional phone call is inserted in the calls place. The called number is stored and the appropriate carrier is determined by locating the calling party's pre-selected carrier choice in telephone company records. When the call identified by the serial number exits the switch it is automatically routed to the correct long distance carrier.

System for converting a No. 5 crossbar telephone switching central

A software-controlled telephone tester permits untrained consumers to test telephone sets by connecting the line cord to the tester and following simple instructions which are sequentially displayed on a panel. Tests are automatically performed after each instruction to provide objective determinations of the operability of the telephone under test. Tested parameters which fall outside specification result in a failure indication. If the user fails to effect certain instructions properly, a 'try again' instruction is generated. Transmission tests are effected automatically by placing the telephone earpiece and/or mouthpiece adjacent a transducer and transmitting at least one tone from the tester through the telephone and back to the tester. Preferrably a two-tone test is employed using a pair of the standard DTMF signalling tones so that transmission testing is effected using the same circuitry employed for DTMF dial testing. The tester transducer is recessed behind the tester panel to reduce the effect of amplitude variations caused by small positional differences in the placing of the mouthpiece/earpiece adjacent the transducer.

Telephone tester

An inexpensive universal telephone signalling tone receiver employs switched capacitor filters to provide selective tone reception in accordance with pre-selected clock signal frequencies. The clock signals, which in the preferred embodiment are provided from an EPROM, are employed to determine the pass band center frequency for respective filters. The selected signalling tones, when received, are rectified and passed to respective sample and hold circuits, the output signals of which are sequentially applied for processing to a common analog-to-digital converter through a multiplexer. Depending upon the clock pulse frequencies programmed for a particular application, the receiver can be used for various signalling protocols, including R1 and R2, in either direction, as well as other single or multi-tone signalling applications. In multifrequency signalling applications, the receiver selectivity permits the processing circuitry to look for two tones of significant amplitude among noise components rather than to continuously adjust threshold detectors, in response to the wide band signal level.

Universal signalling tone receiver

An improved telephone system selector unit employing an electronic control arrangement is capable of directly replacing or being added on to existing electro-mechanical switching arrangements of the Strowger or other types which position themselves directly in response to subscriber dial pulses. The electronic circuitry establishes rapid outlet scanning via a matrix of twelve-pole relays, each of which permits selection of three four-wire lines or four three-wire lines, depending upon a pre-selected operating mode. A digit treatment circuit evaluates the counter digits, selects the appropriate outlet group, and precludes scanning of restricted lines or numbers not present in the numbering plan. During scanning each three or four-wire circuit of each relay is scanned in turn until an available circuit is found. The digit treatment arrangement permits additional outlet groups to be added without regard to the numbering sequence. All of the pulses of a digit are counted before any switching takes place in the selector.

Electronic selector for telecommunications switching

An identifier circuit for connection between a telephone system party line and a party line subscriber to permit identification of a calling party line subscriber with automatic number identifying equipment at a central office. The identifier circuit includes a pair of terminals adapted to be selectively connected to ground in accordance with identification of a particular party line subscriber, a pair of normally nonconductive test transistors each connected between one of the terminals and one of the leads of the party line, a pair of control transistors responsive to voltage on the party line to maintain the test transistors nonconductive and responsive to removal of the party line voltage to permit the test transistors to conduct, and a pair of capacitors charged when a calling subscriber goes off hook and discharged to maintain the test transistors conductive for a predetermined time during which testing of the party line to identify the calling subscriber can be accomplished with automatic number identifying equipment at the central office.

Growing community of inventors

Huntsville, AL, United States of America

Roger F Atkinson