Abstract:
A motor comprises a rotor fixed to a shaft and a stator comprising a permanent magnet on the inner circumferential surface of a motor casing. The shaft extends from the opening end of the motor casing and has a worm wheel in a gear casing. The end face of the gear casing has an annular projection. The motor casing has an outward flange at the opening end. When the motor casing is connected with the gear casing, an elastic O-ring is fitted between a space formed by the outer circumferential surface of the annular projection, an outer vertical seat face of the gear casing and a corner of the outward flange thereby achieving suitable alignment of the motor casing with the gear casing. The permanent magnet is made of Nd magnet which is pressingly fitted on the inner circumferential surface of the motor casing.
Abstract:
A motor comprises a yoke as casing, a shaft extending along a center of the yoke, an annular stator fixed to the yoke and an armature fixed to the shaft to rotate with the shaft inside the stator. The armature comprises a plurality of teeth on the outer circumferential surface. A wire is wound on any of the teeth to form a normal coil. Another wire is wound on another of the teeth to form a brake coil that is a short circuit. When the motor rotates much faster, the brake coil produces magnetic flux which acts as load against the rotation of the motor to allow the motor to rotate slower.
Abstract:
A semiconductor memory write method which, when writing data at a threshold voltage level in a memory cell, is configured to perform two write operations including a preliminary data write operation of writing temporary data at a threshold voltage level lower than that of the data at the threshold voltage level, and a final data write operation of additionally writing final data at the threshold voltage level, includes making at least one of a write time of the preliminary data write operation, a word-line waiting time of verify read, and a bit-line waiting time of verify read, shorter than that of the final data write operation.
Abstract:
A nonvolatile semiconductor memory device according to an embodiment includes: a memory cell array including a plurality of memory cells to store N-value data (N being an integer equal to or larger than 3); and a writing circuit configured to repeatedly execute a writing cycle on a plurality of memory cells until data writing is finished. The writing circuit divides the pulse width of the writing pulse into a plurality of sections to change the pulse height among the sections such that the respective sections provide writing voltages for writing different target threshold levels, and brings the bit line connected to the memory cell to be written with any of the target threshold levels into a selected state synchronously to the section for applying the writing voltage for writing that target threshold level.
Abstract:
A voltage generating circuit generates, at a time of write, a first voltage which is higher than a program voltage, and generates an erase voltage at a time of erase. A first transistor has a current path and a gate, and the first voltage generated by the voltage generating circuit is supplied to one end of the current path and the gate of the first transistor. The first transistor outputs the program voltage from the other end of the current path thereof. A driving transistor has one end of a current path thereof connected to a word line, and has a gate supplied with the first voltage. The driving transistor has the other end of the current path supplied with the program voltage. Stress applying portion applies the erase voltage to the other end of the current path of the first transistor at the time of erase.
Abstract:
A NAND nonvolatile semiconductor memory includes a plurality of series-connected memory cells each includes a charge storage layer and control gate electrode, a plurality of word lines respectively connected to control gate electrodes of the memory cells, a first selection transistor connected between one end of the memory cells and a source line, a second selection transistor connected between the other end of the memory cells and a bit line, and a driver configured to control voltages applied to the word lines. The driver applies a first voltage to a first word line connected to a selected memory cell, and applies a cutoff voltage that cuts off a channel of a memory cell to second word lines of a number not less than three arranged side by side on the source line side with respect to the first word line during a write operation.