PURPOSE: To obtain a highly reliable rotational position reference signal generator by combining two pulse signals having phase difference provided from first and second sensor means and then generating a rotational position reference signal with timing matching with the zero-cross point of the combined signal.

CONSTITUTION: A rotation position reference signal generator comprises first and second sensor means, i.e., coils 11, 12, for generating pulse signals having phase difference when a pulse signal generating magnet 27 mounted on a rotor 29 passes closely thereabout. Means, i.e., a variable resistor 13, for combining pulse signals fed from the sensor means with a variable combination ratio is also provided. Furthermore, means, i.e., a comparing circuit 15, for producing a rotational position reference signal with a timing matching with the time point when the combined signal reaches zero input level of the combined signal is provided. According to the constitution, timing can be adjusted finely by simply varying the combination ratio of two pulse signals.