Abstract: A communication device for estimating the azimuth angle includes a receiving module and an estimating module. The receiving module is configured to sequentially switch several azimuth angles to receive a first signal transmitted at the first transmitting angle from a first transmitting module of the first communication device. The estimation module is configured to calculate several signal powers of the first signal received by the receiving module at the several azimuth angles; to determine the maximum signal power among the several signal powers; to determine the pre-judged AOD according to the azimuth angle of the maximum signal; and to calculate the AOD of the associated first signal based on the pre-judged AOD and at least one azimuth angle adjacent to the pre-judged AOD among the several azimuth angles.

Abstract: A vertical axis wind turbine with wingletted cam-tiltable blades is provided, including: a generator, a shaft interconnected with the generator, and a plurality of blade sets coupled to the shaft. Cam members are provided inside the shaft and have guide sections of predetermined shapes. The blade set includes blades that are coupled to crank arms in contact with the guide sections. Thus, when the blades are located in a windward position and a leeward position respectively, the blades are caused by the guide sections to automatically and easily set at an optimum pressure-receiving condition and a least wind-resistance condition respectively, for receiving wind energy from variable directions so that the shaft can be rotated in low wind speed conditions to drive the generator for power generation.

Abstract: A vertical axis windmill includes a generator, a shaft mounted to the generator; and a plurality of blade sets. The blade set includes a blade rod rotatably connected to the shaft and carrying blades arranged on opposite sides of the shaft. Each blade is divided into first and second moment-inducing sections located on opposite sides of the blade rod. The first moment-inducing section is greater in area than the second moment-inducing section. Each blade is provided, at a predetermined location thereof, with a winglet. Stops for limiting swiveling of the blade are arranged on the blade set. When the blade set is moved so that the blades thereof are located in a windward position and a leeward position respectively, the blades are automatically and easily set at an optimum pressure-receiving condition and a least wind-resistance condition respectively, for receiving wind energy from variable directions.

Abstract: A fluid-driven turbine includes a main driving shaft defining a shaft axis and a plurality of blade sets symmetrically disposed about the main driving shaft. Each of the plurality of blade sets includes a rod extending radially from the main driving shaft in a direction transverse to the shaft axis. The rod defines a rod axis. Each blade set also includes a fluid-tiltable blade connected to the rod and extending along the direction of the rod axis. It has an airfoil shape in cross-section with a leading edge, a trailing edge, and a maximum thickness. The blade is divided into first and second moment-inducing sections located on opposite sides of the rod with the first moment-inducing section being greater in area than the second moment-inducing section. Also, it is rotatable about the rod axis between an optimum pressure-receiving position and a least fluid-resistance position for receiving fluid energy from variable directions.