Abstract: A weft feeding device which alleviates an excessive tension acting on the weft upon feeding of the weft and inhibits breakage of the weft includes a gripper to grip the weft at prescribed times, a length measuring roller located downstream of the gripper, and a pinch roller to hold the weft against the roller at prescribed times. Opening and closing of the gripper is linked with movement of the pinch roller into and out of contact with the length measuring roller. A linear or a rotary solenoid is provided to operate the pinch roller and the gripper by a pulse width modulation method or a linear method.

Abstract: A switching power source control circuit comprising a comparator, a thin-out-processed pulse generator, a thinned-pulse detector, and a reset speed regulator, wherein: the comparator compares an output signal of an error amplifier with a variable reference voltage generated by the reference voltage regulator to generate a signal for performing thin-out operation in accordance with a voltage difference between the output signal of the error amplifier and the reference voltage; the thin-out-processed pulse generator generates thin-out-processed pulses on the basis of the output signal of the comparator; the thinned-out pulse detector detects the generation of thinned-out pulses or driving pulses while always monitoring the thin-out-processed pulses generated from the thin-out-processed pulse generator, and changes the reference voltage of the reference voltage regulator in the case where the thin-out rate is in a range of from 0 to 1/2 in the direction to make it difficult to perform thin-out operation to there

Abstract: A positioning system moves a movable element along a path and detects the movable element in a plurality of predetermined positions spaced along the path. The movable element is positioned selectively in the positions using a signal indicative of the detected movable element in the positions and a positioning command.