Abstract: An auto-detection circuit for detecting video signals includes a reception end for receiving a video signal, a synchronization signal detector coupled to the reception end for generating a waveform according to voltage variation of the video signal, a peak value detector coupled to the synchronization signal detector for determining peak value of the wave form, a direct current voltage level switch coupled to the peak value detector for switching output voltage as first direct current voltage level or second direct current voltage level, and an output end coupled to the direct current voltage level switch for outputting the output voltage.

Abstract: An auto-detection circuit for detecting video signals includes a reception end for receiving a video signal, a synchronization signal detector coupled to the reception end for generating a waveform according to voltage variation of the video signal, a peak value detector coupled to the synchronization signal detector for determining peak value of the wave form, a direct current voltage level switch coupled to the peak value detector for switching output voltage as first direct current voltage level or second direct current voltage level, and an output end coupled to the direct current voltage level switch for outputting the output voltage.

Abstract: A structure of a heat sink fan is disclosed. The heat sink fan comprises an axle and a plurality of blades attached to the axle and circling around the axle. A plurality of the protruded portions are formed on a lower side of the blades of the heat sink fan, wherein the protruded portions are bent into an arch shaped directed towards the axle of the heat sink fan. The heat sink fan is placed into a space of a frame in a manner that the heat sink fan can spin axially within the space of the frame for providing cool air.

Abstract: A fan includes a blade assembly rotatably supported in a frame. The blade assembly includes a cylinder having an outer surface to which blades are mounted and an inner surface to which magnets are mounted. The blade assembly has an axle concentric with the cylinder. The frame includes a casing made of silicone steel that is fixed inside the frame and supports a bearing device. The bearing device defines a central bore rotatably receiving the axle of the blade assembly therein with the cylinder of the blade assembly fit over and spaced from the casing. Windings of conductive wires are encased and fixed in the casing and surround the bearing device for being electrically powered to generate a magnetic field that interacts with the magnetic means of the blade assembly to rotate the blade assembly. The casing includes opposite upper and lower disks with tabs extending between the upper and lower disks.