A device for confirming the stop of a motor, particularly a rotation sensor for extracting the rotation signals of the motor. In the first invention, a high-frequency current signal is supplied to the winding of a tachometer generator incorporated in a motor, and a modulated signal obtained by modulating the high-frequency signal with the output signal of the tachometer generator is output from the rotation sensor to direct the rotation of the motor. In the second invention, the rotation of the motor is extracted after converting the rotation into the variation of the oscillation frequency of an oscillator by utilizing a transducer coil as part of the oscillator. In the third invention, the rotation of the motor is extracted after converting the rotation into the variation of the terminal voltage of a resonance circuit by means of the resonance circuit incorporating the transducer coil.