9 SYSTEMS AND COMPONENTS FOR POWER QUALITY AND MISSION-CRITICAL APPLICATIONS, MEDIUM AND LOW-VOLTAGE SWITCHES, TRANSIENT VOLTAGE SURGE SUPPRESSORS, POWER DISTRIBUTION UNITS, POWER PROCESSORS AND UNINTERRUPTIBLE POWER SUPPLIES; SEMICONDUCTOR DEVICES, NAMELY, DIODES, THYRISTORS, AND GATE TURN-OFF THYRISORS FOR POWER CONTROL APPLICATIONS