Abstract: A fan speed detecting circuit includes a resistor installed in the grounding line of the power circuit of the DC fan motor of a cooling fan, a capacitor, a diode connected between the resistor and the capacitor, and a comparator having an inverter terminal connected to the output end of the diode through the capacitor and a non-inverter terminal connected in parallel to the input end of the diode, wherein a transient pulse current is produced at the resistor upon operation of the DC fan motor, causing the comparator to output a pulse frequency wave indicative of the revolving speed of the DC fan motor.

Abstract: A bearing structure for a rotor shaft of a radiating fan includes a hollow post and, positioned within said hollow post, a bearing for said rotor shaft. An inside wall of bearing has formed therein at least one groove extending circumferentially around the inside wall and arranged to contain a lubricating oil for the bearing, thereby increasing an oil containing capacity of the bearing structure. The bearing is suspended in the hollow post such that a chamber or reservoir is formed below the bearing.

Abstract: An electric jack for the connection of an electric connector, including at least one plug hole disposed on a side wall of the jack for the installation of display means, sets of terminals respectively disposed in the at least plug hole at one end, each of the terminals having a receiving section, said receiving section having a clamp portion at one end and a mounting tail end at the other end extending out of the jack and adapted for connection to power source, and at least one display means for example LEDs respectively mounted in the at least one plug hole and detachably connected to the terminals, each of the at least one display means having a plurality of electrically conductive pins respectively plugged into the receiving section of the terminals in the respective plug hole, and a front side projecting out of the jack through which the display means can be conveniently removed out of the respective plug hole by a pliers or like tool for a replacement.

Abstract: A capacitive coupled BNC connector including an insulative body fastened to a PC board, which is secured to a conductive panel by metal mounting screws, a metal mounting frame fixed to the insulative body and having mounting legs fastened to respective mounting holes on the PC board, a conductive, stepped, cylindrical shell fitted into the longitudinal center through hole to hold a ground terminal and an insulated conductive electric contact, permitting the ground terminal and the conductive electric contact to be respectively welded to the PC board, a metal spring plate fastened to a side opening on the cylindrical shell, a plurality of capacitor elements respectively fastened to respective side slots on the insulative body and stopped between the metal spring plate and the metal mounting frame to filter noises transmitted from the conductive panel.