An LED illumination device for rapidly releasing residual capacitance, which includes a bridge rectifier chip, a current-limiting chip, a light-emitting group, a resistor group and a capacitor. The light-emitting group includes a plurality of first and second LED chips. The resistor group includes a plurality of first and second resistor chips. The first working voltage of the first LED chip is different from the second working voltage of the second LED chip. The first resistance value of the first resistor chip is different from the second resistance value of the second resistor chip. Each first LED chip corresponds to one of the first resistor chips, and each second LED chip corresponds to one of the second resistor chips. When the power supply is turned off, the residual capacitance remaining in the capacitor can be released by cooperation of the first resistor chips and the second resistor chips.

A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

A switching mode power supply preventing a first switch from being falsely triggered. The switching mode power supply detects a peak of an input signal and starts timing a period of time since the arrival of the peak of the input signal is detected. The first switch starts performing the on and off switching operations when the period of time expires.

A circuit includes two input nodes and two output nodes. A rectifier bridge is coupled to the input and output nodes. The rectifier bridge includes a first and second thyristors and a third thyristor coupled in series with a resistor in series. The series coupled third thyristor and resistor are coupled in parallel with one of the first and second thyristors. The first and second thyristors are controlled off, with the third thyristor controlled on, during start up with resistor functioning as an in in-rush current limiter circuit. In normal rectifying operation mode, the first and second thyristors are controlled on, with the third thyristor controlled off.

Embodiments of this application provide charging apparatuses, charging apparatus control methods, and charging systems, and relate to the field of terminal device charging technologies. The charging apparatus includes a rectifier circuit, a transformer, a lower bridge switch, a clamp capacitor, an upper bridge switch, and a controller. The transformer includes a primary coil and at least one secondary coil. The controller is configured to control the upper bridge switch and the lower bridge switch to be alternatively turned on. The controller is further configured to obtain a sampling waveform at a location at which the controller is electrically connected to the transformer when the lower bridge switch is turned off, and, when the sampling waveform is abnormal, turn off the lower bridge switch in a first phase of a next charging cycle. The sampling waveform includes a voltage waveform of the primary coil or a voltage waveform of the secondary coil.

Embodiments of this application provide charging apparatuses, charging apparatus control methods, and charging systems, and relate to the field of terminal device charging technologies. The charging apparatus includes a rectifier circuit, a transformer, a lower bridge switch, a clamp capacitor, an upper bridge switch, and a controller. The transformer includes a primary coil and at least one secondary coil. The controller is configured to control the upper bridge switch and the lower bridge switch to be alternatively turned on. The controller is further configured to obtain a sampling waveform at a location at which the controller is electrically connected to the transformer when the lower bridge switch is turned off, and, when the sampling waveform is abnormal, turn off the lower bridge switch in a first phase of a next charging cycle. The sampling waveform includes a voltage waveform of the primary coil or a voltage waveform of the secondary coil.

Various embodiments are directed to a voltage clamp system comprising: a rectifier; a protected node, a reference node, and one or more internal nodes, coupled to the rectifier; a power converter, coupled to the rectifier via the one or more internal nodes; and one or more output nodes coupled to the power converter and configured to couple to a power sink. The rectifier and the power converter are configured to output power via one or more output nodes coupled to the rectifier, and to limit a component of the voltage between the protected node and the reference node.

An AC to DC conversion device has first and second AC input terminals arranged to be coupled respectively to first and second terminals of a phase of an AC current generator, an H-bridge rectification device comprising two pairs of diodes, each pair being coupled to a respective one of the AC terminals to produce a DC output comprising a rectified back EMF waveform, and a waveform generator. The waveform generator comprises an output coupled to the DC output of the H-bridge rectification device, and is configured to input a unidirectional waveform to the DC output having the same magnitude and fundamental frequency as the rectified back EMF, phase shifted by a predetermined angle relative to the rectified back EMF waveform.

A system for dynamically adjusting coupling coefficients of a non-contact transmission magnetic mechanism, wherein a power supply end is connected to a non-contact transmission electric energy conversion module and a magnetic field regulation electric conversion module respectively by means of an input power consumption measurement unit, the non-contact transmission electric energy conversion module is connected to a transmitting coil by means of a tuning wave-blocking circuit, a receiving coil is provided corresponding to the transmitting coil, the receiving coil is provided on the wave-blocking circuit, the wave-blocking circuit is connected to a load end by means of a rectifying and voltage stabilizing circuit and an output power consumption measurement module, signal loading and extraction modules having a controller and a signal modulation and demodulation module are connected in parallel to two ends of the transmitting coil and the receiving coil

This application provides a switching conversion circuit, including: a power module, supplying power to a switching conversion module and an IC controller; and the switching conversion module is an asymmetrical half-bridge flyback structure and includes at least a first switching transistor, a second switching transistor, a first capacitor, and a transformer. The transformer includes a first secondary-side winding and a second secondary-side winding, and the first secondary-side winding of the transformer is coupled to a load. The IC controller turns on the first switching transistor or the second switching transistor based on a value of a first voltage, so that the switching conversion module enters an operating state to supply power to the load; and turns off the first switching transistor and the second switching transistor based on a value of a second voltage, so that the switching conversion module stops supplying power to the load.