TURBOCHARGER ROTATION DETECTOR

A turbocharger rotation detector includes an oscillator circuit that includes a coil generating a magnetic field inducing an eddy current in blades of a compressor wheel and outputs as a detection signal an AC signal having an amplitude varying with approach and recession of the blades, a first detector circuit for detecting, of the detection signal, a signal component of a positive voltage higher than a reference potential, a second detector circuit for detecting, of the detection signal, a signal component of a negative voltage lower than the reference potential, a first interrupter circuit that, of an output signal of the first detector circuit, interrupts a DC component, a second interrupter circuit that, of an output signal of the second detector circuit, interrupts a DC component, and a differential amplifier circuit to which the signals passing through the first and second interrupter circuits are input.