Cutler-hammer, Inc.

Park-ohio Industries

Robert L Risberg

A plurality of SCR diamond bridge circuits are coupled in series to generate frequencies higher than the individual operating frequencies of the SCR's. The series chain of diamond circuits is preferably coupled in parallel with the series combination of a DC blocking capacitor and an inductive load. The chain is provided with current from a substantially ripple-free constant current source, and the firing times of individual SCR's can be controlled to minimize the di/dt in each SCR.

Solid state frequency converter

A 'chopper' type armature current control system for a D.C. motor when connected across the output of a rectifier, A.C. to D.C. type supply source that is characterized by having closed-loop regulating control, and having overhauling load energy dissipating circuit which is automatically connected between the motor armature circuit and the low potential side of the source output whenever the potential across the output sides of the source exceeds a predetermined value. A modified form provides addition of a fixed D.C. potential to afford enhanced speed of system response, and controlled slow speed reverse operation of the motor.

Growing community of inventors

Milwaukee, WI, United States of America

Robert L Risberg