Abstract: A band saw is disclosed that includes a frame, a guide wheel, and a blade disposed around the guide wheel. A guide wheel chassis can be movably disposed on the frame, the guide wheel rotatably disposed on the guide wheel chassis. The band saw can include a blade tension adjustment assembly including a tensioning motor, wherein operation of the tensioning motor produces movement of the guide wheel chassis and the guide wheel relative to the frame to adjust the tension of the blade. A tension gauge can be positioned to determine a tension in the blade, and a controller can be communicated with the tensioning motor and the tension gauge, the controller operable to receive tension data from the tension gauge and control operation of the tensioning motor based on the tension data to control the tension of the blade.

Abstract: A golf ball with a light-emitting control mechanism is proposed in the present invention. The golf ball has a light-permeable inner shell for packaging a light-emitting module. The light-emitting module includes a timer, a battery set, and a vibration-sensing switch. The timer keeps the light-emitting component emitting light constantly until the light-emitting timer expires. The battery set includes a first battery and a second battery. The vibration-sensing switch makes the first battery provide battery power for the timer after sensing vibration. After the timer obtains battery power, the timer makes the first battery and the second battery provide battery power constantly for the time-emitting component until the light-emitting timer expires.

Abstract: An automatic power-generation light-image fan device is described. It has a fan motor, a vane set, a circuit board, a programmable chip, an automatic power-generation component, a rectifier filter circuit, a magnetic sensor and a positioning magnet. In this device, the circuit board is mounted on the vanes of the vane set and also has plural light-emitting elements, which are respectively connected to I/O terminals of the programmable chip, and an accommodating room is mounted on an inner surface of the vane set, in which an inner circular surface of the accommodating room is circularly mounted by an inductance coil whose ends are connected to an input terminal of the rectifier filter circuit. Thereby, the light-emitting elements mounted on the fan can be controlled to generate various different twinkling light-image variations and an effect of persistence of vision when the fan motor is rotating.