Abstract: To provide a brushless DC motor drive circuit operating with low electric power without a hall element, etc., and to provide a drive circuit for brushless DC motor which may be generally started regardless of an amount of load or size of inertia moment.
Abstract: A self-starting swinging apparatus including a free-running oscillation circuit comprising two transistors which are a PNP transistor and an NPN transistor, the bases of both transistors being connected respectively to the collector of one transistor directly and to the collector of the other transistor through a capacitor for setting a time constant; a driving coil connected to the collector of the transistor with the capacitor connected thereto, as a load on the transistor; and a permanent magnet having a relatively repulsive magnetic pole arrangement of the same polarity as, or having a relatively attractive magnetic pole arrangement of a different polarity from, that of a magnetic pole in a magnetic field which ought to be generated in the driving coil when an electric current is fed to the driving coil from the oscillation circuit, the permanent magnet being relatively movable with respect to the driving coil and capable of performing a relative swing motion under the action of an arbitrary restoring for
Abstract: A display device which can rotate a flap of a display unit in opposite directions in accordance with a predetermined program without necessitating any expensive electronic circuit and switch mechanism. The device comprises a substrate, a flap rotatably supported on the surface of the substrate, a permanent magnet secured to the flap, and a driving magnet located in the rear of the substrate and movable rotative to the substrate. The driving magnet includes an S pole magnetized region and an N pole magnetized region arranged so as to hold the flap at either one of two positions disposed on the substrate.