Abstract: A power supply device is provided. The power supply device includes a power converter and a control circuit. The control circuit is coupled to a power converter. The power converter is configured to convert input power to provide output power. The control circuit is configured to receive a control signal and provide a dummy current according to the control signal and the output power, so that the sum of a current value of the dummy current and a current value of the output power is greater than or equal to a threshold value. The power converter can accordingly convert the input power in a soft switching manner.

Abstract: An AC input voltage detecting device includes a first input, a second input, a determining unit, a first voltage-detecting unit, and a second voltage-detecting unit. The first input and the second input are electrically connected to a neutral line and a live line of an AC power, respectively. The determining unit includes a first power switch, a second power switch, and an output, the first and second power switch are electrically connected in series, and the output is coupled to the second power switch. The first voltage-detecting unit is electrically connected to the first input and the first power switch, the second voltage-detecting unit is electrically connected to the second input and the second power switch. A signal for indicating that the AC power supplies normally is generated from the determining unit while the voltages conducted by the live line and the neutral line are normal.

Abstract: An AC input voltage detecting device includes a first input, a second input, a determining unit, a first voltage-detecting unit, and a second voltage-detecting unit. The first input and the second input are electrically connected to a neutral line and a live line of an AC power, respectively. The determining unit includes a first power switch, a second power switch, and an output, the first and second power switch are electrically connected in series, and the output is coupled to the second power switch. The first voltage-detecting unit is electrically connected to the first input and the first power switch, the second voltage-detecting unit is electrically connected to the second input and the second power switch. A signal for indicating that the AC power supplies normally is generated from the determining unit while the voltages conducted by the live line and the neutral line are normal.

Abstract: A power supply device includes an output port, a transformer, a power switch, a current sensor, a voltage-dividing controller, a voltage-feedback unit, a voltage comparator, a main controller, and a pulse width modulator. The transformer has two inductances. The power switch is electrically connected to a primary winding of the transformer, the pulse width modulator, and the current sensor coupled to the voltage-dividing controller. The voltage-feedback unit is electrically connected to the voltage-dividing controller, the voltage comparator, and the output port. The main controller is coupled to the pulse width modulator and the voltage comparator.

Abstract: A power supply detection apparatus including a base, a couple of longitudinal motion mechanisms, a couple of lateral motion mechanisms, a couple of pin bases and a couple of vertical motion mechanisms is provided. Each lateral motion mechanism is movably arranged on the corresponding longitudinal motion mechanism and thereby driven to move horizontally. Each pin base is driven to move horizontally by the corresponding lateral motion mechanism and a probe is arranged on each pin base. The probe and the perpendicular lateral motion mechanism are moved along respective directions perpendicular with each other. Each vertical motion mechanism is arranged on the corresponding pin base for driving the probe to move vertically. The probes can be thereby moved to automatically detect an electric power status of an electronic component on a circuit board of a power supply.

Abstract: A power supply detection apparatus including a base, a couple of longitudinal motion mechanisms, a couple of lateral motion mechanisms, a couple of pin bases and a couple of vertical motion mechanisms is provided. Each lateral motion mechanism is movably arranged on the corresponding longitudinal motion mechanism and thereby driven to move horizontally. Each pin base is driven to move horizontally by the corresponding lateral motion mechanism and a probe is arranged on each pin base. The probe and the perpendicular lateral motion mechanism are moved along respective directions perpendicular with each other. Each vertical motion mechanism is arranged on the corresponding pin base for driving the probe to move vertically. The probes can be thereby moved to automatically detect an electric power status of an electronic component on a circuit board of a power supply.

Abstract: A transformer includes a bobbin, a primary winding set, a plurality of secondary winding sets, and a magnetic core. The bobbin includes a winding part. The primary winding set is wound on the winding part. The secondary winding sets twist together and are wound on the winding part for uniform leakage inductance in secondary winding sets of the transformer. The magnetic core is assembled with the bobbin. The magnetic core, the primary winding set, and the twisted secondary winding sets collectively achieve function of power conversion.

Abstract: A battery free off-grid solar inverter system includes an inverter and a controller. The inverter is used for converting a direct current voltage provided by a solar panel into an alternating current voltage. The inverter has an input terminal, an output terminal, and a control terminal. The input terminal is used for coupling to the solar panel for receiving the direct current voltage, and the output terminal is used for coupling to a load for coupling the alternating current voltage. The controller is coupled to the control terminal for gradually increasing the alternating current voltage to make the direct current voltage be gradually decreased when the battery free off-grid solar inverter system is turned on. The controller stops increasing the alternating current voltage when the direct current voltage is lower than a predetermined direct current voltage value.

Abstract: An active power factor correction circuit. The circuit comprises a voltage source having a first end and a second end, an inductor having an end coupled to the first end of the voltage source, a first rectifying device having an anode coupled to the other end of the inductor and a cathode, a second rectifying device having a cathode coupled to the cathode of the first rectifying device and an anode, a first switching device having a first terminal coupled to the anode of the first rectifying device and a second terminal, a second switching device, having a first terminal coupled to an anode of the second rectifying device and the second end of the voltage source and a second terminal, a capacitor having two ends coupled to the cathode of the second rectifying device and the second terminal of the second switching device respectively, and an auxiliary circuit for switching the first and second switching devices under zero voltage.

Abstract: An active power factor correction circuit. The circuit comprises a voltage source having a first end and a second end, an inductor having an end coupled to the first end of the voltage source, a first rectifying device having an anode coupled to the other end of the inductor and a cathode, a second rectifying device having a cathode coupled to the cathode of the first rectifying device and an anode, a first switching device having a first terminal coupled to the anode of the first rectifying device and a second terminal, a second switching device, having a first terminal coupled to an anode of the second rectifying device and the second end of the voltage source and a second terminal, a capacitor having two ends coupled to the cathode of the second rectifying device and the second terminal of the second switching device respectively, and an auxiliary circuit for switching the first and second switching devices under zero voltage.

Abstract: A cell voltage balancer for balancing the voltage of the first cell and the voltage of the second cell. The cell voltage balancer includes the first input terminal, the second input terminal and the third input terminal. The cell voltage balancer includes a transformer, the first switch and the second switch. The transformer includes a primary winding and a secondary winding. The first switch and the primary winding are serially connected between the first input terminal and the second input terminal. The second switch and the secondary winding are serially connected between the second input terminal and the third input terminal. The first switch and the second switch are switched on and off alternatively. While the first switch is on and the second switch is off, the primary winding stores energy of the first cell in the transformer. On the contrary, the secondary winding recovers energy stored in the transformer into the second cell.