Abstract: In an actuator, an electric power supply to a position-detecting detector for an object to be driven can be carried out in a timely manner during a power failure to thereby suppress an electric power consumption in the position-detecting detector, whereby duration time of a power-failure compensation battery can be prolonged, and a variety of detectors can be selected and utilized without limitation in accordance with a use environment and usefulness. During the power failure, a switching means 40 establishes a linking state in which an input shaft 11 of a reduction mechanism 10 and a manual inputting means 30 are linked to each other. When the linking state is detected by a detecting means, an electric power is fed from a battery 80 to a rotation detector by a control section 70, so that the control section 70 can obtain a displacement of the object to be driven, based on a signal output from the rotation detector.

Abstract: In an actuator, an electric power supply to a position-detecting detector for an object to be driven can be carried out in a timely manner during a power failure to thereby suppress an electric power consumption in the position-detecting detector, whereby duration time of a power-failure compensation battery can be prolonged, and a variety of detectors can be selected and utilized without limitation in accordance with a use environment and usefulness. During the power failure, a switching means 40 establishes a linking state in which an input shaft 11 of a reduction mechanism 10 and a manual inputting means 30 are linked to each other. When the linking state is detected by a detecting means, an electric power is fed from a battery 80 to a rotation detector by a control section 70, so that the control section 70 can obtain a displacement of the object to be driven, based on a signal output from the rotation detector.

Abstract: The present invention provides a method of culturing zooplankton that allows solids serving as feed for zooplankton to remain in a culture medium, while preventing accumulation of growth inhibitors of zooplankton and growth of bacteria, and an apparatus for culturing by the same. The culture method of the present invention includes removing a growth inhibitor of the zooplankton and/or a water-soluble nutrient for bacteria from a culture medium containing the zooplankton by a solid/liquid separation membrane with perfusion. The culture method of the present invention can produce a culture for use as feed for fishes or crustaceans containing at least 50,000 per ml of highly lively zooplanktons.