Gte Automatic Electric Labs Inc.

Paul U Lind

James S Butcher

Andrew Chan

Thomas E White

A power converter which supplies AC or positive or negative DC output voltage with positive or negative current while isolating the output voltage from the input power source. This converter includes a pulse width modulator converts power amplitude signals to pulses of proportionate width. A power driver circuit applies these pulses to a sychronous demodulator and low pass filter via a pulse transformer. A low output impedance is presented to all output disturbances such that the converter can source or sink current in true four quadrant operation, including the passing of power from output to input when a load voltage exceeds the intended supply voltage.

Bi-lateral four quadrant power converter

A microcomputer controlled key telephone line circuit for use in a key telephone. A microcomputer is used to sequentially and alternately scan the ringing leads and tip and ring leads associated with connected line circuits and A leads associated with connected telephone stations. The microcomputer operates in response to changes in the status of these leads to control the normal key telephone functions such as line pickup, hold and ringing current detection, lamp illumination and tone signaling.

Growing community of inventors

Lombard, IL, United States of America

Paul U Lind