OVERLOAD CURRENT PROTECTION APPARATUS

摘要

A current sensor which constitutes an overload protection apparatus and senses a current supplied from a power source to a load is constituted by providing a magnetic sensor having the effect of magnetic impedance MI, an AC supply means which impresses AC on this sensor, a bias current supply means which supplies a bias current to a bias coil, a peak sensing means which senses the peak of a change in impedance of the magnetic sensor as a change in voltage, and a switch which selects the output of the peak sensing means in accordance with each phase. A holding means which holds switch outputs one after another and an amplification means are provided in common to enable current sensing for each phase. Thus, a range of current sensing is enlarged to reduce power consumption and cost.