Abstract: One three-phase transformer (71A) out of two paired three-phase transformers among three-phase transformers provided for respective feeder lines outputs, as operating power, first three-phase AC power of the same voltage phase as that of power-supply power. The other three-phase transformer (71B) out of the two paired three-phase transformers outputs, as the operating power, second three-phase AC power of a voltage phase shifted by ?/6 from that of the power-supply power. The power storage device (4) of a crane apparatus (10) stores DC power supplied from a three-phase full-wave rectifier (1) to a common bus (B), and supplies the stored power to the common bus (B) upon reduction of the DC power.

Abstract: A three-phase full-wave rectifier (21) performs full-wave rectification of three-phase AC power (11A) supplied from ground power supply equipment, and supplies obtained DC power (12A) to a common bus (B). A ?-Y connection type three-phase transformer (2) outputs three-phase AC power (11B) of a voltage phase shifted by ?/6 from the three-phase AC power (11A). A three-phase full-wave rectifier (22) performs full-wave rectification of the three-phase AC power (11B) output from the three-phase transformer (2), and supplies obtained DC power (12B) to the common bus (B).

Abstract: One three-phase transformer (71A) out of two paired three-phase transformers among three-phase transformers provided for respective feeder lines outputs, as operating power, first three-phase AC power of the same voltage phase as that of power-supply power. The other three-phase transformer (71B) out of the two paired three-phase transformers outputs, as the operating power, second three-phase AC power of a voltage phase shifted by ?/6 from that of the power-supply power. The power storage device (4) of a crane apparatus (10) stores DC power supplied from a three-phase full-wave rectifier (1) to a common bus (B), and supplies the stored power to the common bus (B) upon reduction of the DC power.

Abstract: A three-phase full-wave rectifier (21) performs full-wave rectification of three-phase AC power (11A) supplied from ground power supply equipment, and supplies obtained DC power (12A) to a common bus (B). A ?-Y connection type three-phase transformer (2) outputs three-phase AC power (11B) of a voltage phase shifted by ?/6 from the three-phase AC power (11A). A three-phase full-wave rectifier (22) performs full-wave rectification of the three-phase AC power (11B) output from the three-phase transformer (2), and supplies obtained DC power (12B) to the common bus (B).

Abstract: The guide device for craning a container has guides so arranged that they can be moved vertically by a raising/lowering device mounted on the spreader body and can be positioned at the corners of the spreader. The guides are lowered by the raising/lowering device and secured to the bottom corners of the container held by the spreader. Then the spread parts of the guides project from the lower end of the container to secure the spreader to the container. The structure of the spreader is simple and the weight is light.

Abstract: The guide device for craning a container has guides so arranged that they can be moved vertically by a raising/lowering device mounted on the spreader body and can be positioned at the corners of the spreader. The guides are lowered by the raising/lowering device and secured to the bottom corners of the container held by the spreader. Then the spreaded parts of the guides project from the lower end of the container to secure the spreader to the container. The structure of the spreader is simple and the weight is light.

Abstract: A digital multi-frequency receiver for the use in an electronic telephone exchange system for detecting MF signals (700,900, 1100, 1300, 1500 and 1700 Hz) in the CCITT No. 5 system. The digital multi-frequency receiver comprises a recursive digital filter for detecting each of the MF signals on a time divisional basis, an absolute value circuit for providing the absolute value of the output of the recursive digital filter, a comparator for comparing the output of the absolute value circuit with a variable threshold to provide the detected MF signal information, and a circuit for providing the variable threshold by selecting the maximum value from among, (i) the predetermined fixed value, (ii) the product of the value .alpha. which is less than but close to 1 and the maximum value of the variable threshold circuit in a preceding frame, and (iii) the maximum value of the output of the absolute value circuit in a present frame.