Abstract: A mounting arrangement for printed circuit boards where electrical and mechanical connection is maintained by the characteristics of the contacts included in the connector. While support is provided for the printed wiring board, no retenion means other than the contacts themselves are employed. The combination of a rigid and a flexible contact inhibits "walking" of the board due to vibration.

Abstract: A method and system for detection of authorized connections to a telephone line where such connections are for the purposes of intercepting voice or data messages. The original or base line impedance would be measured by the system in response to the entry of a special code. The base line is stored in memory and used for subsequent impedance comparisons.

Abstract: An electronic telephone instrument circuit capable of dialing (address signaling) in either pulse or tone mode. The circuitry permits the placement of a call through a rotary dial only system into a second network that is of a tone only nature. The included circuitry has very high return loss and relatively high level of tone capability and is designed to function with a variety of types of dialer integrated circuits. The present circuitry provides part of its DC current supervision while in the voice mode through the included tone amplifiers circuit thereby minimizing components and reducing current load through the voice network.

Abstract: A transistorized current amplifier based on a cascode stage feeding into a composite transistorized output stage. The amplifier employs a constant current source, decoupling (isolation) from the power source and a signal limiting network to lower distortion on high signal input conditions. A two-wire device, the amplifier derives signal and power from a telephone line. Surge protection is provided by a signal limiting network and the inclusion of relatively high value resistors in the circuit.