A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. The power supply also includes a voltage doubler power factor correction (PFC) circuit coupled between the pair of input terminals and the three-level LLC circuit, and a control circuit coupled to operate the at least four switches to supply the DC voltage output to the load.

A resonant power converter for converting a DC input voltage to AC or DC output voltage, includes a transistor, and a first inductor connected to an input port for a DC voltage to be converted, the drain being connected to the input port by way of the first inductor, the converter furthermore comprising a first resonant network, connected between the drain of the transistor and ground, the first resonant network being configured so as to extract the fundamental component of a drain-source voltage of the transistor and to phase-shift it by a phase shift angle such that the fundamental component and the drain-source voltage are in phase opposition and thus generate a sinusoidal drive signal.

A self-driven active clamp circuit applied to a flyback converter having a transformer and a switch has a clamp switch and a resistor. The clamp switch is connected between a first capacitor and a second capacitor in series. Another terminal of the first capacitor is connected to a first terminal of a primary-side winding of the transformer. Another terminal of the second capacitor is connected to a second terminal of the primary-side winding of the transformer and the switch of the flyback converter. A terminal of the resistor is connected to a control terminal of the clamp switch. Another terminal of the resistor is connected to the second terminal of the primary-side winding of the transformer and the switch of the flyback converter.

An apparatus includes a rectifier coupled to a coil of a wireless power transfer system, the rectifier comprising a first leg and a second leg, wherein the first leg comprises a first switch and a second switch connected in series between a first voltage bus and a second voltage bus, and the second leg comprise a third switch and a fourth switch connected in series between the first voltage bus and the second voltage bus, and wherein a gate drive signal of the first switch is derived from a signal in phase with a voltage on a first terminal of the coil, and a gate drive signal of the third switch is derived from a signal in phase with a voltage on a second terminal of the coil.

A controller for a power converter having at least a first switch and a second switch. Each switch is a transistor with a collector terminal, an emitter terminal, and a base terminal. The controller is connectable to the base terminals of the first and second switches to provide a base current to the base terminals of the first and second switches, and connectable to the emitter terminals of the first and second switches to provide a short-circuit between the base and emitter terminals of the first and second switches. The controller also comprises a timing circuit for controlling the provision of the base current and the short-circuit in a sequence. An associated method is also provided.

A method for controlling a discharge of a power storage device includes: a first step of discharging, in a first section of a discharging period, a part of an electric charge stored in a power storage through a first discharge path and a second discharge path of a discharge circuit; and a second step of discharging, in a second section of the discharging period, a remaining part of the electric charge through the second discharge path. The first discharge path includes a zener diode connected to one end of the power storage. The second discharge path includes a first transistor connected to the one end of the power storage. The first section is a period in which a voltage of the one end of the power storage is higher than a breakdown voltage of the zener diode. The second section is a period in which a voltage of the one end of the power storage is lower than the breakdown voltage of the zener diode. An output current of the first transistor in the second section is greater than an output current of the first transistor in the first section.

A device includes a voltage regulator circuit, a power switch circuit, and a control circuit. The voltage regulator circuit generates an output voltage at an output terminal. The power switch circuit is coupled to the voltage regulator circuit. The control circuit receives a first control signal and generates a second signal that includes a first portion gradually declining between a first time and a second time later than the first time. When the voltage regulator circuit is turned off and a logic state of the first control signal changes at the first time, the power switch circuit is turned on at the second time, in response to the second control signal, to adjust the output voltage.

An electromagnetic charge-sensitive electric mosquito swatter, comprising a charging-discharging circuit (1), a boost circuit (3) and a central control circuit (4). The charging-discharging circuit (1) provides required power to the boost circuit (3). Also comprised are an electromagnetic charge space scanning circuit (5) and a gate circuit (6); the gate circuit (6) is bridged between the electromagnetic charge space scanning circuit (5) and the central control circuit (4) so that when the electromagnetic charge space scanning circuit (5) senses a holding signal of a human hand holding the swatter, the holding signal is converted into a startup signal by means of the gate circuit (6) and is transmitted to the central control circuit (4); and the central control circuit (4) drives the charging-discharging circuit (1) to provide power to the boost circuit (3). The present mosquito swatter has the advantages of being convenient and safe to use and being effective in shocking mosquitos.

The present invention concerns a power converter including: a capacitor (CBUS) having first and second electrodes respectively coupled to first (E1) and second (E2) input terminals via a current-limiting element (R1, L1); at least one normally-on transistor (K1, K2, K3, K4, K5, K6); a circuit (170) for powering a circuit (CMD_K1, CMD_K2) for controlling the normally-on transistor; and a switch configurable to, in a first configuration, couple first (g) and second (h) input terminals of the power supply circuit (170) respectively to the first (E1) and second (E2) input terminals of the converter, upstream of the current-limiting element (R1, l1) and, in a second configuration, connect the first (g) and second (h) input terminals of the power supply circuit (170) respectively to the first and second electrodes of the capacitor, downstream of the current-limiting element (R1, L1).

A switch-mode power supply includes a pair of input terminals, a pair of output terminals, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. First and second ones of the at least four switches define a first half-bridge and third and fourth ones of the at least four switches define a second half-bridge. The power supply also includes a fifth switch coupled across the second switch and the third switch to short circuit the second switch and the third switch when the fifth switch is closed, and a control circuit. The control circuit includes a voltage-controlled oscillator (VCO) and multiple logic gates and flip-flops coupled to operate the at least four switches with zero-voltage switching (ZVS).