Abstract: An outlet (1) includes a plurality of blade receiving members (13) adapted in use to be connected respectively to a plurality of DC supply lines (Wdc1 and Wdc2), and to be connected respectively to a plurality of blades (21) of an outlet plug (2). The outlet (1) is configured to supply DC power from the plurality of the DC supply lines (Wdc1 and Wdc2) to the outlet plug (2) via the plurality of the blade receiving members (13). The outlet (1) includes a wiring detecting means (3). The wiring detecting means (3) is configured to determine proper wiring when the plurality of the DC supply lines is connected respectively to the plurality of the blade receiving members at proper polarity, and to determine improper wiring when the plurality of the DC supply lines is connected respectively to the plurality of the blade receiving members at improper polarity.

Abstract: The output receptacle includes a first blade reception member adapted to be supplied with a zero voltage and at least two second blade reception members adapted to be supplied with different voltages. The at least two second blade reception members are arranged to be shaped or located differently from each other. Two-pole blades of each of at least two plugs include a first blade configured to be connected to the first blade reception member, and a second blade. The second blades of at least two plugs are shaped or located differently from each other for connection respectively to the second blade reception members.

Abstract: An outlet (1) includes a plurality of blade receiving members (13) adapted in use to be connected respectively to a plurality of DC supply lines (Wdc1 and Wdc2), and to be connected respectively to a plurality of blades (21) of an outlet plug (2). The outlet (1) is configured to supply DC power from the plurality of the DC supply lines (Wdc1 and Wdc2) to the outlet plug (2) via the plurality of the blade receiving members (13). The outlet (1) includes a wiring detecting means (3). The wiring detecting means (3) is configured to determine proper wiring when the plurality of the DC supply lines is connected respectively to the plurality of the blade receiving members at proper polarity, and to determine improper wiring when the plurality of the DC supply lines is connected respectively to the plurality of the blade receiving members at improper polarity.

Abstract: An electric tool having the capability of achieving a high working efficiency is provided. This tool comprises an output shaft rotated by reversible motor, a rotational-direction switch for switching a rotational direction of the output shaft in either forward or reverse direction, first memory for storing a plurality of operation modes of the output shaft with respect to one of the forward and reverse directions, operation-mode switch for selecting one from the operation modes, second memory for temporarily storing an operation mode selected by the operation-mode switch in a use of the electric tool at the one of the forward and reverse directions; and a controller for automatically setting the electric tool in the operation mode stored in the second memory in the next use of the electric tool at the one of the forward and reverse directions.

Abstract: An electric tool having the capability of achieving a high working efficiency is provided. This tool comprises an output shaft rotated by reversible motor, a rotational-direction switch for switching a rotational direction of the output shaft in either forward or reverse direction, first memory for storing a plurality of operation modes of the output shaft with respect to one of the forward and reverse directions, operation-mode switch for selecting one from the operation modes, second memory for temporarily storing an operation mode selected by the operation-mode switch in a use of the electric tool at the one of the forward and reverse directions; and a controller for automatically setting the electric tool in the operation mode stored in the second memory in the next use of the electric tool at the one of the forward and reverse directions.

Abstract: In a small electric motor vehicle equipped with an electric motor for driving wheels through a reduction gear mechanism, a first predetermined voltage is immediately applied to the electric motor when a drive-off instruction is generated from vehicle standstill and then the voltage is increased at a predetermined rate until the voltage exceeds a second predetermined voltage, and is then controlled such that the driving speed converges to a desired speed. With this, since the application of the first predetermined voltage slightly rotates the electric motor to take up reduction gear mechanism backlash, shock at drive-off caused by reduction gear mechanism backlash can be reduced or eliminated even when a high-capacity electric motor is used to enhance hill-climbing performance, and smooth drive-off is possible.

Abstract: In a small electric motor vehicle equipped with an electric motor for driving wheels through a reduction gear mechanism, a first predetermined voltage is immediately applied to the electric motor when a drive-off instruction is generated from vehicle standstill and then the voltage is increased at a predetermined rate until the voltage exceeds a second predetermined voltage, and is then controlled such that the driving speed converges to a desired speed. With this, since the application of the first predetermined voltage slightly rotates the electric motor to take up reduction gear mechanism backlash, shock at drive-off caused by reduction gear mechanism backlash can be reduced or eliminated even when a high-capacity electric motor is used to enhance hill-climbing performance, and smooth drive-off is possible.

Abstract: A vector control method is provided for controlling a rotor speed of an induction motor by an inverter which provides an AC current of varying frequency to the induction motor, and a vector controller which provides control voltage Vu, Vv, Vw, in response to an excitation current command i.sub.1d*. The excitation current command is indicative of an excitation current being fed to the induction motor, a desired rotation speed command .omega..sub.r*, and a primary frequency .omega., for controlling the inverter to vary the rotor speed. The method includes the steps of detecting a primary current being fed to the induction motor, analyzing the detected primary current to obtain an excitation current i.sub.1d and a detected torque current i.sub.1q, multiplying a torque value represented by the detected torque current i.sub.1q by a predetermined motor constant K.sub.m to obtain a slip frequency .omega..sub.s, and adding the obtained slip frequency .omega..sub.s to the rotation speed command .omega..sub.

Abstract: A moving-coil linear motor is formed with a stator means forming a guide and having a permanent magnet array having opposite poles alternately at constant intervals in longitudinal direction of the stator means, and a mover means mounted on the stator means for being movable through an electromagnetic force along the stator means, the mover means having three-phase moving coils wound in bipolar system on cores U-shaped in section. Positive and negative voltages are alternately applied through brushes to the moving coils of the mover means, while its U-shaped cores are opposed to the permanent magnet array, disposing the array between both leg portions of the U-shaped cores, with the magnetic efficiency of the motor thereby remarkably improved while sufficiently effectively minimizing the size.