Abstract: A stator for use in an ultrasonic motor is made of sintered metal. The stator includes a circular land portion which is connected to a piezoelectric element, and a plurality of teeth formed at the land portion by a plurality of radial slits. Each tooth includes a top surface for contacting a rotor, a front surface for forming a part of peripheral surface of the stator, and a rear surface facing the axial center. The front and rear surfaces are formed parallel to the axial center.

Abstract: A bipolar RAM apparatus comprises a memory cell array where a plurality of memory cells are connected in parallel between a pair of word lines arranged in N rows decoders are provided for the individual rows of the memory cell array respectively and each serves to select the corresponding row of the memory cells. N drive transistors are for driving, when turned on, the rows of the memory cells individually in response to the respective drive outputs of the decoders. N discharge circuits comprise discharge transistors whose emitters are mutually connected in common between the circuits and whose collectors are connected respectively to the word lines in the individual rows. Coupling capacitors apply the inverted signals of the drive outputs at a nonselected time to the bases of the discharge transistors and resistors apply a fixed bias voltage to the bases of the discharge transistors.