Abstract: There are included a control circuit to control sequence of excitation of a stepping motor, a switching circuit to switch electric power to be supplied to the stepping motor based on an instruction from the control circuit, and a stop circuit to stop an operation of the switching circuit in a case where temperature of the switching circuit becomes a specified temperature or higher, and the control circuit controls the switching circuit in a mode where the stop circuit operates before the stepping motor is damaged by heat.

Abstract: Magnetic forces are used as a controlled actuation mechanism to move and position objects of interest. In one embodiment, a first spherical surface has at least one magnetic positioner attached. A second spherical surface is positioned to move relative to the first spherical surface. A plurality of controlled electromagnets are spaced about the second spherical surface. Control logic energizes at least one of the controlled electromagnets to create magnetic interaction with at least one magnetic positioner to move the first spherical surface relative to the second spherical surface.

Abstract: An improved tactile feedback device for a remote control robot using a repulsive force of a magnet, which is capable of achieving a more accurate operation and productive work of the robot by transmitting the tactile information of a work object positioned between grippers of robot hands to a robot operator in a central control room, which includes a computer for receiving a tactile information and for outputting a tactile feedback signal in accordance with the tactile information; a driving circuit unit for converting a tactile feedback signal outputted from the computer into a current; and a tactile feedback device for transferring a predetermined pressure to an operator in cooperation with a repulsive force between an electromagnet and a permanent magnet when the electromagnet is driven in accordance with a current applied thereto from the tactile feedback device driving unit.

Abstract: A switching current amplifier for stepping motors utilizing a square hysteresis loop transformer to measure the motor winding load current directly, to determine the high and low switching points in reference to the position command signal, to compare the motor winding current to the determined switching points and to provide a switching signal to switch the output devices of the amplifier when the motor winding current reaches the switching points. The square hysteresis loop transformer is constructed to have a high common mode signal rejection.