LOAD ACTUATION CIRCUIT WITH A SURGE PROTECTING FUNCTION

摘要

In a load actuation circuit of an emitter-follower circuit arrangement, a surge detection circuit detects a power surge voltage superposed on a power voltage of a power line. A feed circuit supplies current to a control electrode of an output transistor (i.e. emitter-follower transistor) from the power li ne to turn on the output transistor forcibly when any power surge voltage is detected by the surge detection circuit. Thus, the power surge voltage is absorbed by the output transistor.