DEMAGNETIZATION CIRCUIT, CURRENT MEASURING DEVICE, AND POWER MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To demagnetize a magnetic core constituting a plurality of current sensors while reducing a power source capacity of an AC signal source which generates an AC attenuation signal.SOLUTION: A demagnetization circuit includes: feedback coils 25 functioning as demagnetization coils wound around magnetic cores 21 of a plurality of current sensors 11a to 11c having the magnetic cores 21 installed on electric wires La to Lc in a state that corresponding electric wires La to Lc are included, respectively; a plurality of AC signal sources 31a to 31c starting generation of AC attenuation signals Ssa to Ssc of the same cycle with start signals Sta to Stc to be input as triggers and outputting the AC attenuation signals Ssa to Ssc to the feedback coils 25 of the associated current sensors 11a to 11c; and a start signal output circuit 32 outputting the start signals Sta to Stc for causing the AC signal sources 31a to 31c to start the generation of the AC attenuation signals Ssa to Ssc by mutually shifting timings within a time equivalent to one cycle of the cycle of an AC attenuation signal Ss.