Abstract: A power converter with output voltage level indicating device is disclosed. The power converter includes a casing, an interior of which is disposed with a control circuit. The control circuit includes a feedback circuit and a DC-to-DC conversion circuit. The feedback circuit is coupled to the DC-to-DC conversion circuit and connected to a level-selecting terminal by at least one resistor to provide a feedback signal to the DC-to-DC conversion circuit which in turn changes the voltage level of the DC output. An output socket is formed at the casing, which is connected with the control circuit. The output socket includes two primary, power terminals and at least one secondary, level-selecting terminals. A level-selecting terminal device is connected to the output socket via an extension cable for getting the DC voltage and supplying the DC voltage to an appliance via an output terminal.

Abstract: A dual band linear antenna array, having a set of radiator constructed by four elongate metal plates. The metal plates are arranged to form a rectangular array. By serially connecting to a signal feed terminal, the roots of the metal plates are connected to a copper tube via a coaxial cable external conductor (ground signal). One pair of the metal plates has the same length, which is about one quarter wavelength of the high-frequency electric wave received thereby and transmitted therefrom. The other pair of the metal plates has longer length at about one quarter wavelength of a low-frequency electric wave received thereby and transmitted therefrom. Thereby, an array of dual band antenna is obtained to achieve omni-directional reception and transmission of radiation.

Abstract: A dual band linear antenna array, having a set of radiator constructed by four hard linear conductors. The linear conductors are equidistantly arranged at four corners and extend parallel to each other. By serially connecting to a signal feed terminal, the roots of the linear conductors are connected to a copper tube via a coaxial cable external conductor (ground signal). Three of the linear conductors have the same length, which is about one quarter wavelength of the high-frequency electric wave received thereby and transmitted therefrom. The other linear conductor has the length longer than these three linear conductors at about one quarter wavelength of a low-frequency electric wave received thereby and transmitted therefrom. Thereby, an array of dual band antenna is obtained to achieve omni-directional reception and transmission of radiation.

Abstract: The present invention is related to an improved structure for a module connector for assembling on a case of a computer and comprises: a case has a lower cover and an upper cover, the upper cover and the lower cover have a second containing slot and a first containing slot individually for different connectors, the first and second containing slots construct several containing spaces, the first containing slot has a stopping portion for blocking connectors and hook portions for linking two sides of each connector up; a metal member wraps around an end surface of the case, the metal member is established plural homologous holes corresponding to the containing spaces of the case, the metal member has a plurality of flexible touching members individually arranged into cross-section slots of the containing spaces; hence stable assembly for the case and the connectors is made, and channels of the module connector for electrically connecting outside are effectively shielded.

Abstract: A cell phone charging circuit of a USB interface. The charging circuit is supplied with a DC power of 5V via the USB interface and split into two, one has a first resister R1 connected to an emitter of a PNP transistor Q1 in series, and the other has two serially connected diodes D1 and D2. The diodes D1 and D2 have a negative thermal coefficient. The negative electrode of the diode D1 is connected to the base of the transistor, the collector of the transistor serves as a charging output terminal, such that the emitter voltage VEB of the transistor Q1 is the same as the voltage VD2 of the diode D2. Therefore, the current flowing through the resistor is VD1/R1, and the voltage and current limiting function is obtained. When the temperature of the battery increases for charging, the voltage VD1 is reduced to decrease the output current, such that temperature compensation is achieved.