ROTATIONAL SPEED DETECTOR

PROBLEM TO BE SOLVED: To provide a rotational speed detector capable of improving the reliability of a detected rotational speed. SOLUTION: A timing generating circuit 22 detects the rotational speed of a resolver 1 based on a signal of the resolver 1 digital-converted by an R/D converter 20. The timing generating circuit 22 makes each latch circuit section 24 store one-rotation duration of the resolver 1 whenever the resolver 1 rotates by an angle obtained by dividing 360 degrees into plurality. A selection circuit 26 selects the last one-rotation duration based on the information from the timing generating circuit 22. A speed calculation section 27 calculates the rotational speed of a monitoring object based on the one-rotation duration selected by the selection circuit 26. COPYRIGHT: (C)2008,JPO&INPIT