Contact state detecting method of switch for power meter and switch driving circuit for power meter

摘要

Problem to be solved: to detect a contact state detecting method of a power meter capable of detecting the number of accurate opening and closing operations by detecting the state of the contact of the switch and the switch driving circuit of the power meter.The movable contact 15b opens and closes with respect to the fixed contact 15A due to the supply or disconnection of the current to the exciting Coyle 11, whereby the load of power 1L of the power system is reducedSwitch circuit of a power meter for interrupting supply toWhen the movable contact 15b is open to closedThe first current waveform of the exciting Coyle 11 is obtained when the movable contact 15b is switched by the first driving signalWhen the movable contact 15b is closedA current sensor 4 for acquiring a second current waveform of exciting Coyle 11 by a second driving signalThe CPU 2 is provided for detecting whether or not the movable contact is closed based on the difference between the first and second current waveforms detected by the current sensor 4.Diagram