Abstract: In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.

Abstract: Disclosed is a speed controlling method and apparatus in which a suitable current or voltage command is given to a moving body on the basis of the relation between a speed detection signal obtained by detecting the speed of the moving body and an externally supplied speed command signal.

Abstract: A permanent magnet electric machine such as, for example, a motor or generator, including a permanent magnet field member, an armature having salient magnetic poles and armature windings. A greatest common division of the number of magnetic poles of the field member and the salient magnetic poles having the armature windings differs from the number of magnetic poles. A group of grooves is formed between the salient magnetic poles having an interval of 2/3M.pi., with M being an integer which is not a multiple of three. To reduce the occurrence of cogging torque, auxiliary grooves are provided on the surface of the salient poles at positions which are spaced apart from positions of the grooves by (.pi./3)K+(.pi./6), in terms of electrical angle, with K being an integer.

Abstract: A chip-like electronic component series comprises a tape-like member formed with a plurality of apertures arranged in the longitudinal direction for receiving one by one a plurality of chip-like electronic components, cover sheets adhered to both surfaces of the tape-like member for sealing the apertures, and feeding perforations formed equispaced in the longitudinal direction of the tape-like member. The chip-like electronic component series is fed by using the feeding perforations, and the chip-like electronic components are supplied therefrom onto a print circuit board, for example, by stripping the upper cover and by pushing the electronic components one by one onto the print circuit board while the lower cover sheet is broken, by picking up the electronic components therefrom one by one, or the like to place the same onto the print circuit board.