United Networks Inc.

Other

Anaconda-ericsson Inc.

Manu-tronics, Inc.

Alfred M Hestad

Jan Synek

Levi L Rose

Michael Tentler

Harold O Hansen

Harry O Hansen

A telephone call routing and charging system using processor circuitry can automatically select the most economical route for individual telephone calls. The system includes a signal direction detector for automatically determining the time span of a call for charge purposes from the time the call is answered to the time the call is terminated.

Telephone call routing and charging system

A speaker telephone system having hands-free telephone sets with microphones and loud-speakers and including circuitry for preventing feedback between the loud-speakers and the microphones in both the transmitting and receiving modes by automatically controlling the amplification of the signals coming from the microphones and going to the loud-speakers, as a function of the signal direction, while still maintaining the microphones and loud-speakers electrically coupled to the telephone lines.

Speaker phones

A solid state subscriber station network which provides transmitting, receiving and regulating functions using a single active element. The transmitted signals, the received signals and the regulatory functions can be separately varied within proscribed limits without adversely affecting the other functions.

Subscriber station networks

A two-way amplifier arrangement which automatically controls current flowing in the transmission circuits to maintain that current at a fixed level. The two-way amplifier arrangement finds utility as a conference amplifier and as a two-way trunk amplifier.

Two-way amplifier arrangement

An improved dialing system, basically powered through the line, that provides automatic dialing of stored, frequently used numbers and the last number dialed. Self-test capabilities are provided to enable and test all the stored number memory locations automatically. Outgoing call restrictions are provided with a programmable code to bypass the call restriction. The system automatically converts push button dialing to rotary outpulsing, or generates dual tone multi-frequency dialing signals.

Dialing system

A push button to rotary dial converter system for converting push button telephones to provide rotary dial type pulsed outputs. The system provided is universal and can be used with almost any subscriber set that is made to provide push button signals to the telephone system and is especially useful when the telephone system involved is not equipped to receive variable frequency dialing signals. Responsive to the operation of the selected push buttons, pulses are transmitted through the line. The system is unique, among other ways, in that the connection to the network is electronically opened during out pulsing and a parallel power supply arrangement is employed; and it is applicable even when only one pair of hook switche contacts are available, and one side of the pair of hook switch contacts are tied together. The system further includes a bridge circuit for maintaining the polarity on the subscriber set independent of telephone line polarity reversals, a portion of the bridge circuit also being used to prevent operation of the subscriber set ringer in response to the rotary dial type pulses.

Push button to rotary dial converter systems

A telephone switching system utilizing matrices composed of monolithic chips which include a plurality of cross points and controls therefor. The lines and trunks attached to the unique matrices include unique circuitry, such as two-way amplifiers, which compress the signals going into the matrices, but amplify the signals coming out of the matrices. The unique combination of the matrix signal amplitude compressing two-way amplifiers and monolithic chip matrices enables effective utilization of micro-processors for controlling the selection of paths through the matrix on a space division system.

Growing community of inventors

Chicago, IL, United States of America

Alfred M Hestad