A bidirectional direct current converter includes a controller that controls a switching transistor in the bidirectional direct current converter to reduce an inductance of an inductor, thereby reducing a size and costs of the inductor, and further reducing a size and costs of the entire bidirectional direct current converter. The bidirectional direct current converter further includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and a capacitor. The controller is coupled to the first switching transistor, the second switching transistor, the third switching transistor, and the fourth switching transistor. The controller performs complementary control on the first switching transistor and the third switching transistor, and performs complementary control on the second switching transistor and the fourth switching transistor.

The present disclosure provides a switching power device. A control unit of the switching power device includes a first state, a second state, a third state and a fourth state. In the first state, a first switch is turned on, and a second switch is turned off. In the second state, the first switch is turned off, and the second switch is turned on. In the third state, the first and second switches are turned off. In the fourth state, a voltage of a connection node of the first and second switches is less than that in the third state. The control unit repeats the first state, the second state, the third state, and the fourth state, and lengthens a period of the fourth state as an input voltage increases.

Provided is a drive circuit 1 including: a switching unit 3 including a first transistor Tr1 that constitutes an upper arm, and a second transistor Tr2 that is connected to the first transistor Tr1 in series and constitutes a lower arm; and a drive power supply 5 in which a positive electrode is connected to a gate terminal of the first transistor Tr1 and a negative electrode is connected to a source terminal of the second transistor Tr2. When turning off the switching unit 3, the first transistor Tr1 is turned off after the second transistor Tr2 is turned off

An electric power converter includes an inverter, an insulating transformer, and a rectifier. The inverter converts an input DC voltage, supplied from a DC power supply, to an AC voltage outputted at an AC output side of the inverter, and includes at least one semiconductor switching device made of wide bandgap semiconductor material configured to carry out turning-on and turning-off operations at a specified frequency to thereby invert the DC voltage to the AC voltage at the specified frequency; and at least one freewheeling diode made of silicon-based semiconductor material respectively connected to the at least one switching device in inverse parallel.

The present disclosure refers to direct current-to-direct current (DC-DC) converters and power supplies including the same. In an embodiment, a DC-DC converter includes a first switching circuit, a second switching circuit, a fourth capacitor coupled to a second node, and an inductor-capacitor (LC) filter coupled to a third node. The first switching circuit includes a first transistor coupled between a first capacitor and an input node, a second transistor coupled between the first capacitor and a second capacitor, a third transistor coupled between a first node and a third capacitor, and a fourth transistor coupled between the third capacitor and a ground node. The second switching circuit includes a fifth transistor coupled between the second capacitor and the third capacitor, a sixth transistor and a seventh transistor coupled between the first capacitor and the third capacitor, and an eighth transistor coupled between the first capacitor and the ground node.

A switching element drive device that reduces a switching loss while suppressing noise with an inexpensive configuration, is provided. The switching element drive device includes a current sensor configured to measure a load current flowing through a load, a voltage sensor configured to measure an input voltage inputted from a power supply, and a control part configured to output a command value of a gate drive voltage to a gate drive voltage supply part, the gate drive voltage supply part being configured to supply the gate drive voltage for driving a switching element disposed between the power supply and the load, wherein the control part is further configured to determine the command value of the gate drive voltage based on the load current and the input voltage.

There is provided an electric-power conversion system controller in which even when the temperatures of a switching device and a diode included in the driving circuit for a converter become high, the performances of the devices are prevented from being deteriorated and the lifetimes thereof are prevented from being shortened. In the case where even when determining that direct-coupling control is to be performed, a positive-polarity-side device temperature is higher than a determination temperature, the electric-power conversion system controller performs voltage-boosting control in which the positive-polarity-side switching device and the negative-polarity-side switching device are on/off-controlled in an on/off period; in the case where the positive-polarity-side device temperature is the same as or lower than the determination temperature, the electric-power conversion system controller performs direct-coupling control in which the positive-polarity-side switching device is turned on and the negative-polarity-side switching device is turned off.

A converter includes a transformer, an active clamp circuit, a primary side switch, a secondary side switch, a load detection circuit, a state detection circuit and a control circuit. The active clamp circuit is electrically coupled to the primary winding of the transformer, and includes a clamp switch. The primary side switch is electrically coupled to the primary winding and a primary ground terminal. The secondary side switch is electrically coupled to a secondary winding of the transformer and a load. The control circuit outputs a control signal to turn on or turn off the clamp switch. The control circuit sets a blanking time according to the load state signal, such that the clamp switch is turned on when a drain-source voltage of the primary side switch is at a peak value of a resonance after the blanking time starting from the reference time point.

The present disclosure is directed to a pulse frequency modulation (PFM) control method for a boost converter and apparatus for carrying out the method. A boost converter includes an inductor and a transistor coupled thereto. A control circuit is arranged to control the transistor to cause current pulsed to be sourced through the inductor. When operating in a PFM mode, the control circuit may control the timing of pulses such that, at the beginning of a specified time period, current pulses may be sourced with no spacing between successive pulses. After a desired number of pulses have been sourced, no pulses are sourced for the remainder of the specified time period. Nevertheless, the number of pulses sourced over the time period corresponds to a desired average frequency of pulses.

The present invention relates to a power converter including a transformer; a current doubler including a switch element and connected to a secondary side of the transformer to double a current of the transformer according to an operation of the switch element; and a voltage resonator connected to the switch elements, wherein the voltage resonator includes a switch element and a capacitor which are connected to each other in series.