Abstract: A Hall effect device test circuit which detects Hall effect device operate and release point failures. A magnetic field circuit, a voltage switching circuit, a comparison circuit, a retriggerable monostable multivibrator circuit and a visual indicator circuit are included. The comparison circuit compares the Hall effect device switching voltage to a predetermined threshold and controls the multivibrator circuit which causes a visual pass/fail signal to be provided.

Abstract: An arrangement for monitoring the admittance of a line during a frequency sweep is disclosed which upon detection of the characteristic admittance level determines the loaded or unloaded status of a transmission line. Output logic associated with detection circuits provides a digital indication of the status detected.

Abstract: A device for clamping a cable or similar article comprising two identical members. A pair of positioning arms and the latch of one clamp member engage positioning arm guides and a catch of the other member and vice-versa. Both clamp members together retain and hold the cable. The clamp may be mounted to a panel via an optionally provided mounting anchor connected to the base of each clamp member.

Abstract: An arrangement for the distribution of digital service tones in a distributed processor digital switching network is shown. These service tones are distributed between the time stages of the digital switching network with a minimum of interprocessor communication. This is accomplished by transmitting the particular service tone, from the terminating time stage which detects the need for tone application, through the switching network paths already established for voice communication. These service tones include such tones as reorder tone, dial tone, busy tone, DTMF tones, MF tones and ringback tone.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio transmitter and a radio receiver. Also included in the base unit is bimodal tuned circuit operable as a filter and as an oscillator.

Abstract: A remote unit for use in a wireless extension telephone system having a self-contained dipole antenna. Utilizing the unique construction of the telephone instrument housing one element of the dipole is included in a planar element that functions normally to direct sound to a self-contained microphone and the other element of the antenna is a static shield used to protect components on printed circuit board included within the extension unit.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio receiver and a radio transmitter. Also included in the remote unit is a modulator connected to said remote unit radio transmitter and circuitry limiting the amplitude of the modulated signals produced by said transmitter. A dialing circuit connected to said modulator causes the amplitude of each outgoing dial pulse to be transmitted at a level substantially higher than when no dial pulses are present.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Included in both the base and extension units are a radio receiver and a radio transmitter. Also included in the remote unit is a bimodal tuned circuit operable as both a filter and as an oscillator.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio receiver and a radio transmitter. The remote unit transmits tone signals of a first amplitude for line seizure and of a second amplitude for line pulsing in response to manually initiated dial pulses. A dial pulse detection circuit at the base unit differentiates between the two types of pulses breaking connections to the telephone line in response to incoming dial signals of the second amplitude.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio receiver and a radio transmitter. Also included in the remote unit is a modulator connected to the radio transmitter and circuitry limiting the amplitude of modulated signals produced by said transmitter. A dialing circuit connected to the modulator causes the amplitude of each outgoing signal representing a dial pulse to be transmitted at a level substantially higher than when no dial pulses are present. At the base unit a dial pulse detection circuit differentiates between the modulated signals received by the associated radio receiver, providing connections to the telephone line in response to signals of a first amplitude and breaking the line in response to each received pulse of a higher level amplitude.

Abstract: This circuit provides for extending a multiplexed address and data bus to remotely located computer peripheral devices. The present circuit eliminates skew of transmitted signals between microcomputers and their associated peripheral devices for lengths of up to one hundred feet. This circuit regenerates the bus timing for the peripheral device to accommodate the skew introduced by the length of cable and its associated drivers and receivers.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units including a radio receiver and a radio transmitter. Also included in both base and remote units is a bimodal tuned circuit operable as a filter and operable as an oscillator.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and extension units each include a radio receiver and a radio transmitter. Also associated with the base unit is an auxiliary telephone and switch operated intercom signalling means, which when manually operated cause a radio signal to the transmitted to the remote unit for signalling purposes after which conversation may insue between users of the auxiliary telephone and the remote extension unit.

Abstract: This circuit provides for retrieving common control interoffice signaling (CCIS) data from a PCM voice data stream of a T1 span. T1 spans interconnect switching offices. Unused data bits in these T1 spans are encoded with CCIS data and transmitted between the switching systems where the CCIS data is recovered.

Abstract: A circuit for increasing the inductance of a transformer as used in a telephone line circuit. An operational amplifier with appropriate feedback is connected across a separate winding of the transformer to provide the reactive inductance. To compensate for changes in resistance of the winding, a field effect transistor is controlled by the same amplifier output to provide a positive resistance in the feedback path and thus maintain balance. An operational amplifier and diode are arranged to cooperate with the negative inductor to prevent lock-up.

Abstract: A single CCIS central processing unit is employed to receive and transmit CCIS data from a central switching office to other CCIS offices via modems, or digital trunk units and T1 spans. This apparatus facilitates orderly and timely data exchange between a CCIS central processing unit and a plurality of data terminal equipment. Every 10 milliseconds the CCIS CPU scans all the data terminal equipment. However, particular data transmissions require interaction at a more rapid rate. The present invention provides for a high priority data transmission from the terminal equipment to the central processing unit intermingled with regular priority messages.

Abstract: A time shared conference circuit for establishing conference calls in a T-S-T digital switching network provides for trapping certain PCM voice data from the output PCM voice data stream of the conference circuit. Data is automatically trapped for detection of errors such as parity. Data in any specific time slot may be trapped for a non-error condition under control of a processor.

Abstract: A time shared conference circuit for establishing conference calls in a T-S-T digital switching network provides for automatically inserting predefined test data into unused time slots of its output PCM voice data stream. The transmission of this predefined data verifies the interface operation of the conference circuit with the switching network.

Abstract: The conference circuit provides for establishing a conference call between three conferees in a T-S-T digital switching network. The voice samples of the three conferees are sequentially stored in input buffers. When all three conferees' samples are stored, the samples are transferred to working buffers, while the input buffers store three other conferees' samples. In the time slot succeeding the transfer to the working buffers, two conferees' voice samples are compared. During the next time slot, the resultant of the comparison is transmitted to the third conferee. This conference arrangement provides for time sharing up to 64 three-port conference calls via the switching network.

Abstract: An automated switching office arrangement for switching data link transmission from analog to digital data or vice versa is disclosed. Any or all of a number of data links may be automatically switched between the digital and the analog transmission modes. This automated switching may be accomplished locally within the switching office or from a remote location.