Abstract: A power converter to supply power to each phase of a three-phase motor includes a booster circuit connected to a DC power supply to boost an input voltage input from the DC power supply in response to a pulse width modulation boosting signal, an inverter connected to the booster circuit and including a three-phase switching circuit including switches, and an output connected to the three-phase switching circuit to supply power to each phase of the three-phase motor, and a controller to output the pulse width modulation boosting signal to the booster circuit and output the pulse width modulation boosting signal to the booster circuit when detecting that the booster circuit is in a boosted state.

Abstract: A power supply controlling system is configured to supply power to a load and includes a first power supply device having a first outputting voltage and current to the load, a second power supply device having a second outputting voltage and current to the load, and a buck converter which is selectively connected to the first power supply device or the second power supply device first and is then connected in parallel with the power supply device without converter and the load. The buck converter is selectively connected to the power supply device with a higher voltage, and controls the output voltage of the converter to make it conform to the voltage of the other power supply device, so as to connect the two power supply devices in parallel and output current to the load.

Abstract: An AC inrush current testing device is disclosure. The AC inrush current testing device includes a grid voltage peak point calculator, a grid voltage period and timing detector, a switch, an autotransformer, and a main relay. The grid voltage period and timing detector is connected to an AC power source and the grid voltage peak point calculator. A movable contact of the switch is connected to the AC power source. A first winding of the autotransformer is connected to the AC power source, a second winding of the autotransformer, and a first stationary contact of the switch. A third winding of the autotransformer is connected to a second stationary contact of the switch and the second winding. The main relay is electrically connected to the grid voltage peak point calculator, the second winding, and the third winding. A method for testing AC inrush current is further disclosed.

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: An energy-saving power supply apparatus includes a bridge rectifier, a diode bypass circuit and a control circuit. The diode bypass circuit is electrically connected to the bridge rectifier. The control circuit is electrically connected to the diode bypass circuit and the bridge rectifier. The bridge rectifier includes a plurality of diodes. After the control circuit receives a power start signal, the control circuit is configured to control the diode bypass circuit, so that a part of the diodes are bypassed to save energy.

Abstract: An AC inrush current testing device is disclosure. The AC inrush current testing device includes a grid voltage peak point calculator, a grid voltage period and timing detector, a switch, an autotransformer, and a main relay. The grid voltage period and timing detector is connected to an AC power source and the grid voltage peak point calculator. A movable contact of the switch is connected to the AC power source. A first winding of the autotransformer is connected to the AC power source, a second winding of the autotransformer, and a first stationary contact of the switch. A third winding of the autotransformer is connected to a second stationary contact of the switch and the second winding. The main relay is electrically connected to the grid voltage peak point calculator, the second winding, and the third winding. A method for testing AC inrush current is further disclosed.

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: An energy-saving power supply apparatus includes a bridge rectifier, a diode bypass circuit and a control circuit. The diode bypass circuit is electrically connected to the bridge rectifier. The control circuit is electrically connected to the diode bypass circuit and the bridge rectifier. The bridge rectifier includes a plurality of diodes. After the control circuit receives a power start signal, the control circuit is configured to control the diode bypass circuit, so that a part of the diodes are bypassed to save energy.