The present invention involves method and apparatus for analyzing measured signals that are modeled as containing primary and secondary portions. An exemplary embodiment of an electrical component includes an injection-molded housing encapsulating an equalizer circuit and with pins protruding from one end. After die mounting and wire bonding, a continuous strip of plastic or resin molding covers the wire bonds on one side and the edge of the silicon on the other, protecting the lead frame strip and other parts, leaving the active sensor area exposed. The emergency stop control unit issues a disconnection command to the electromagnetic contactor, when the switching between the first and second operation modes is sensed, and automatically confirms whether or not the power supply line is disconnected.