Controls for high-current solid-state switches

摘要: A solid-state AC switch (comprising inverse parallel thyristors) that ''''opens'''' in high-speed response to abnormally high currents is so controlled as prevent automatic reclosing if (1) the overcurrent condition persists for longer than a predetermined length of time or (2) an appropriate opening command received. For relatively high-current applications, sets plural thyristors are used, and concurrent turn on each set promoted by jointly applying thereto composite firing signals comprising component short duration magnitude superimposed another long low magnitude. D R W I N G