Abstract: A smart sine wave step-down converter is provided including: an input and rectifying unit; a high-frequency modulation unit including a first and a second switching tubes, the drain of the first switching tube being connected to an output terminal of the input and rectifying unit, the source of the first switching tube being connected to the drain of the second switching tube, the grids of the first and the second switching tubes being connected with two-path anti-phased PWM pulse signals; an inductance filtering unit including a inductor and a first capacitor, the front end of the inductor being connected to the source of the first switching tube; an inverting paraphase unit; a filter controlling unit including a third switching tube and an electrolytic capacitor having an anode connected to the output terminal of the input and rectifying unit and a cathode connected to the drain of the third switching tube.

Abstract: A long-life intelligent step-down conversion device includes a high-frequency modulation unit including a first switching tube and a second switching tube, an inductance filtering unit including a filtering inductor, and an inverting paraphase unit. The drain of the first switching tube is connected to a DC voltage, its source connects to the drain of the second switching tube, and the source of the second switching tube is carthed. The grids of the first and second switch tubes are respectively connected to two-path anti-phased PWM pulse signals. The front end of the filtering inductor is connected to the source of the first switching tube. The inverting paraphase unit, with its input terminal connected to the back end of the filtering inductor, is configured for invertedly converting a half-wave pulse voltage output from the back end of the filtering inductor to a sine AC voltage. Which of easy to carry, without electrolytic capacitors, improving the service life, avoiding interference to the power grid.

Abstract: A smart switching charger and a power connection device thereof are disclosed. The smart switching charger includes a socket a plug and a DC power line. The socket is mounted to a power device to acquire electricity therefrom and includes a first contact group. The plug includes a second contact group corresponding to the first contact group. At least one of the first and second contact groups is magnetic to the first contact group attracting to the second contact group. When the first contact group attracts to the second contact group, the plug acquires electricity from the socket. The DC power line connects with the plug for transmitting electricity to electrical devices. Such configuration may obtain a reliable electrical connection between the socket and the plug through magnetic adsorption. A simple and convenient operation of connecting the socket and the plug is obtained, and lifespan of the charger is improved.