| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance detection accuracy of current to be detected and accelerate operation by excluding influence of dispersion in magnetic characteristics of a core. <P>SOLUTION: A current sensor 1 comprises: a core 11; a coil 12 wound around the core 11; an excitation circuit 13 for applying a triangular wave excitation signal, in which a current magnitude at each peak exceeds a current magnitude saturating the core 11, to the coil 12; and a detection circuit 14 for detecting current to be detected on the basis of a time difference between a point of time that the core 11 is saturated by application of the excitation signal and a point of time that the core 11 is temporarily turned to non-saturation and then saturated again. The detection circuit 14 includes a detection processing unit 15 for outputting a detection signal indicating induced electromotive force generated in the coil 12 due to the application of the excitation signal. The detection processing unit 15 includes an inverting amplifier 21, a resistor 23 connected between the excitation circuit 13 and the inverting amplifier 21 and a feedback route 24 connecting between an output terminal and an input terminal of the inverting amplifier 21, and the coil 12 is connected on the way of the feedback route 24. <P>COPYRIGHT: (C)2013,JPO&INPIT |
