SWITCH WITH PRE-ALARM

摘要

In a switch with pre-alarm means (101) having pre-alarming apparatus (20, 21) and an indicator (103) for alarming that value of current flowing on a load is above a predetermined alarming level, output of the pre-alarming apparatus is held at a predetermined level after the value of the current once becomes above the alarming level by self-holding function of thyristor (CR) even when the value of the current becomes below the alarming level after that.