HIGH-PERFORMANCE SINGLE-CHIP GATING CIRCUIT FOR A PHASE-CONTROLLED BRIDGE

The increasing availability of single-chip low cost microcontrollers h as made it possible to reconsider conventional hardware designs for a variety of gating circuits. This paper, in particular, presents the de sign of a gating circuit for a six-pulse phase-controlled bridge utili zing a single-chip programmable microcontroller. The dynamic performan ce of the proposed gating circuit is similar to an analog circuit impl ementation. The resolution of the firing angle is better than 0.1 degr ees at 60 Hz. Moreover, the system is designed to operate over a frequ ency range of 3 Hz to 120 Hz, and to automatically adapt to changes in line frequency. The experimental verification of the performance crit eria are also presented. Finally, an example of a special application for a dual-bridge ac to dc converter is presented.