Abstract: A peak detector circuit providing a comparator that produces a low voltage output by pulling the output to common when an input signal exceeds a reference voltage and that produces a floating output by not conducting when the input signal does not exceed the reference voltage. A low output from the comparator generates a base current sufficient to drive a PNP transistor, which in turn drives current to a DC output capacitor. Until the input signal exceeds the reference voltage, neither the comparator nor the PNP transistor need to conduct and, consequently, the peak detector consumes relatively little power. The peak detector can be beneficially employed in a network interface unit or other transmission line unit.

Abstract: An improved, more intelligent network interface unit capable of processing signals received from a high speed transmission media and outputting the received signals without substantial amplification or reduction. The network interface unit comprises a regenerator circuit which detects T1 signals from said high-speed transmission media and outputs a digital stream to a serial data processor for processing via a micro-controller. A wave shaper circuit receives the output from the serial data processor and, in conjunction with the micro-controller and a level detector circuit, regenerates signals having substantially the same wave shape and amplitude as the original T1 signals received from said transmission media.

Abstract: An improved, more intelligent network interface unit capable of processing signals received from a high speed transmission media and outputting the received signals without substantial amplification or reduction. The network interface unit comprises a regenerator circuit which detects T1 signals from said high-speed transmission media and outputs a digital stream to a serial data processor for processing via a micro-controller. A wave shaper circuit receives the output from the serial data processor and, in conjunction with the micro-controller and a level detector circuit, regenerates signals having substantially the same wave shape and amplitude as the original T1 signals received from said transmission media.

Abstract: A DC to DC power converter in the form of a pulse-width modulator is shown which can sense via an indication of duty cycle how much reserve power is available for loads using the present input voltage. The device is for use at the end of a telephone line where the input voltage power supply impedance can be appreciable. When the reserve power, as detected in the power converter, reaches a minimum critical level, a signal is sent out requesting the voltage supply to increase the available voltage to the power converter.

Abstract: A power converter is provided located in a remote terminal of a telephone system, the telephone system having a central office which powers a plurality of telephone loops with a DC voltage having at least two substantially different levels. The remote terminal power converter derives remote terminal output load voltages including a low voltage regulated supply from the DC voltage provided to the loop from the central office. The remote terminal power converter comprises a synchronous rectifier for providing a predetermined low voltage regulated supply. The remote terminal power converter further comprises a receiving circuit connected to the loop for receiving DC voltage from the central office and supplying a low voltage output for producing the low voltage regulated supply. A switch is associated with the receiving circuit for producing an output signal on the low voltage output, the output signal having sequential charging, flyback, and discontinuous intervals.

Abstract: A miniature multi-impedance transformer module specially adapted for use in telephony. In the preferred embodiment a pair of multi-winding transformers and a coil are configured to have connecting pins projecting both above and below the bodies thereof. The upward projecting pins are inserted in a printed circuit board carrying a plurality of connectors in a predetermined array. This assembly is installed in a miniaturized case and potted in place with the lower projecting pins extending below a mounting surface of the case. The lower surface and the downward projecting pin are adapted for ready mounting on a second printed circuit board. The connectors at the top of the module receive shorting plugs for selectively connecting the windings of the transformers and coil to provide impedance matching in telephone equipment. The miniaturized board mounted modules are readily adapted for high density rack mount applications.