<p>A rotation speed signal detector comprises a cylindrical rotor magnet having n rotor magnet poles provided along the inner circumference and m ¢m > n! rotation speed detection magnet poles provided along the outer circumference; a stator winding; a rotation speed detection coil including a pair of coil conductors provided on the outer side of the rotor magnet in the form of a ring; and a terminal base having output terminal pins connected to one end portion of the coil conductors and a short circuiting terminal pin for connecting the other ends of the coil conductors. Each conductor may be short-circuited by a conductor on a winding conductor processing substrate provided separately instead of being short-circuited by the terminal pin.</p>
