This application provides a direct current conversion circuit and a photovoltaic inverter. The direct current conversion circuit includes an RC circuit, and a first direct current conversion unit and a second direct current conversion unit that are mutually connected in parallel. The RC circuit includes a resistor and a capacitor that are connected in series. Two ends of the RC circuit are respectively connected to one end of a first switching transistor in the first direct current conversion unit and one end of a second switching transistor in the second direct current conversion unit. When a state of the first switching transistor or the second switching transistor is switched, the other switching transistor remains in an on or off state.

A power-regulated Power Receiving Unit (PRU) of an RWPT system, comprising an ML post-regulation stage via which a load is connected to the PRU; a controller circuit, being adapted to: determine target/predicted values for voltage and current of the a Power Transmit Unit (PTU) of the RWPT system; determine the wireless medium characteristics and resonant frequency of the RWPT system; generate an overall system model by using First Harmonic Approximation (FHA); determine a desired output power; calculate the voltage V.sub.S1 of the first harmonic; use V.sub.S1 to calculate the equivalent reflected impedance Z.sub.o of the load; and calculate the duty-cycle d using the predicted values of the efficiency n the conversion ratio M(D) and the calculated equivalent reflected impedance Z.sub.o.

A power-regulated Power Receiving Unit (PRU) of an RWPT system, comprising an ML post-regulation stage via which a load is connected to the PRU; a controller circuit, being adapted to: determine target/predicted values for voltage and current of the a Power Transmit Unit (PTU) of the RWPT system; determine the wireless medium characteristics and resonant frequency of the RWPT system; generate an overall system model by using First Harmonic Approximation (FHA); determine a desired output power; calculate the voltage V.sub.S1 of the first harmonic; use V.sub.S1 to calculate the equivalent reflected impedance Z.sub.o of the load; and calculate the duty-cycle d using the predicted values of the efficiency n the conversion ratio M(D) and the calculated equivalent reflected impedance Z.sub.o.

The present disclosure belongs to the technical field of display. Provided are a DC-DC boost circuit and a driving circuit board. The DC-DC boost circuit includes a power MOSFET, and a control circuit electrically connected to a control terminal of the power MOSFET and configured to provide a control signal capable of controlling turn-on and turn-off of the power MOSFET. A voltage value of a high-level signal in the control signal is 0.5 to 0.8 times a maximum rated value of a gate-source voltage of the power MOSFET.

The present disclosure belongs to the technical field of display. Provided are a DC-DC boost circuit and a driving circuit board. The DC-DC boost circuit includes a power MOSFET, and a control circuit electrically connected to a control terminal of the power MOSFET and configured to provide a control signal capable of controlling turn-on and turn-off of the power MOSFET. A voltage value of a high-level signal in the control signal is 0.5 to 0.8 times a maximum rated value of a gate-source voltage of the power MOSFET.

An apparatus includes a plurality of optional units attached to an apparatus body, in which the apparatus is configured to identify the plurality of optional units, the apparatus body includes an output section that outputs a power supply voltage generated by the apparatus body, the optional units each include: a power receiving section that receives a first direct-current (DC) voltage; a step-down circuit that steps down the first DC voltage received; a power output section that outputs a second DC voltage obtained by stepping down the first DC voltage by the step-down circuit; and a controller that detects the first DC voltage or the second DC voltage and determines a level number at which a corresponding one of the optional units is attached on a basis of the first DC voltage or the second DC voltage detected, and the optional units include: an optional unit at a first level, connected to the apparatus body; and at least one optional unit provided at a succeeding or higher level of the optional unit at the first level, in which the power receiving section of the optional unit at the first level is connected to the output section of the apparatus body, and the power receiving section of the at least one optional unit is connected to the power output section of one of the optional units, the one provided at a preceding level of the at least one optional unit.

An apparatus includes a plurality of optional units attached to an apparatus body, in which the apparatus is configured to identify the plurality of optional units, the apparatus body includes an output section that outputs a power supply voltage generated by the apparatus body, the optional units each include: a power receiving section that receives a first direct-current (DC) voltage; a step-down circuit that steps down the first DC voltage received; a power output section that outputs a second DC voltage obtained by stepping down the first DC voltage by the step-down circuit; and a controller that detects the first DC voltage or the second DC voltage and determines a level number at which a corresponding one of the optional units is attached on a basis of the first DC voltage or the second DC voltage detected, and the optional units include: an optional unit at a first level, connected to the apparatus body; and at least one optional unit provided at a succeeding or higher level of the optional unit at the first level, in which the power receiving section of the optional unit at the first level is connected to the output section of the apparatus body, and the power receiving section of the at least one optional unit is connected to the power output section of one of the optional units, the one provided at a preceding level of the at least one optional unit.