Abstract: By making different duty controls at the time of change in rotating speed and at the time of stable rotating speed, respectively, it is possible to realize the driving of a brushless motor 3 which enables smooth and rapid change of a rotating speed coping with a load.

Abstract: In a brushless motor, during a synchronized operation mode, n kinds of driving waveforms having the first to n-th patterns are sequentially outputted and the outputting of the n-th pattern is followed by cyclically outputting the patterns again in a sequence from the first pattern, thereby generating a rotating magnetic field in an armature winding. Upon transition from the synchronized operation mode to a rotor position detection operation mode, the commutation signal is changed over from the synchronizing signal to a signal based on the rotor position detector signal after the (n-1)th pattern has been outputted and at a timing when the n-th pattern is to be subsequently outputted. Thereby, upon transition from the synchronized operation mode to the rotor position detection operation mode, the commutation signals are linked in a proper sequence so that smooth mode transition becomes possible without the addition of any special ancillary circuit.

Abstract: In a brushless motor, the frequency of an output signal of a synchronizing signal generation unit, a duty ratio in a synchronized operation mode and a duty ratio in a rotator position detection operation mode are set such that a rotating speed in the rotator position detection operation mode becomes equal to or lower than a rotating speed in the synchronized operation mode, thereby enabling smooth change-over from the synchronized operation mode to the rotator position detection operation mode.

Abstract: This invention relates to a method or apparatus by which comparatively low-voltage electric wires and cables laid at power stations and other locations can be diagnosed for deterioration of their polymer-insulation in a non-destructive way. The method or apparatus comprises applying a torsional force to the electric wire or cable, detecting the resulting repulsion as a torque, and estimating the degree of deterioration of the polymer-insulation in the electric wire or cable on the basis of the detected value of torque.

Abstract: An operator console for use in an imaging diagnostic apparatus, comprising means for displaying a full length figure of a human body; means for displaying respective figures representing the axial plane, sagittal plane, and coronal plane of the body figure; means for displaying respective figures representing pitching, yawing, and rolling of these planes; plane designating means which are manipulated by an operator; and tilt direction designating means which are manipulated by an operator, whereby the plane and the tilt direction designated by the operator are displayed by means of the figures in connection with the body figure.