Magnetic detection apparatus and current detection apparatus

A current detection apparatus comprising:

• a magnetic detection apparatus, wherein the magnetic detection apparatus comprises:
• a core to which magnetism to be detected is applied,
• an exciter configured to excite the core with an excitation signal,
• a detector configured to detect induced voltage according to a time change of magnetic flux generated by the core,
• a wave detector configured to detect a wave from a signal corresponding to the induced voltage by using a detection signal corresponding to the excitation signal and to generate a signal according to the magnetism to be detected,
• a signal converter configured to generate and output to the exciter an excitation signal that has a spread spectrum of a signal having an excitation frequency and to generate and output to the wave detector a detection signal that has a spread spectrum of a signal having a detection frequency of twice the excitation frequency, and
• a low pass filter configured to attenuate a frequency component, equal to or greater than a cutoff frequency, of the signal according to the magnetism to be detected generated by the wave detector, wherein the signal converter is configured to generate the excitation signal so that a value of a width of a frequency band of the excitation signal is greater than twice a value of the cutoff frequency;
• a current detection core in which the core of the magnetic detection apparatus is installed;
• a feedback coil wound around the current detection core;
• and
• an amplifier configured to apply a current to the feedback coil according to a signal outputted from the low pass filter of the magnetic detection apparatus, wherein
• the current detection core is positioned to surround a wire through which a current to be detected flows.