Operating an electrical load controller includes, in one aspect, detecting zero-crossings of an AC waveform, determining periods each corresponding to a full cycle of the AC waveform, determining a frequency of the AC waveform based on the determined periods, and controlling a supply of AC power to a load based thereon using the determined frequency to fire a switching circuit of the electrical load controller. In another aspect, a method includes maintaining a minimum on-time for which a control signal to the switching circuit is to remain in an ON state to fire the switching circuit; based on a desired load level setting of the electrical load controller, setting a corresponding control signal turn-on time to turn the control signal to the ON state to conduct the supply of AC power to the load, the control signal turn-on time corresponding to a firing angle of half cycles of the AC power; selecting a control signal turn-off time to turn the control signal to the OFF state, where the selecting is made between (i) a first turn-off time equal to the set turn-on time plus the minimum on-time, and (ii) a second turn-off time equal to a default turn-off time for turning the control signal to the OFF state, the control signal turn-off time corresponding to a second angle of half cycles of the AC power; and controlling the supply of AC power to the load by selectively controlling the switching circuit to conduct the supply of AC power to the load, the controlling the supply of AC power to the load including: based on turning the control signal to the ON state during a half cycle of the AC power at the set control signal turn-on time, holding the control signal in the ON state until the selected control signal turn-off time during the half cycle.

The present disclosure relates to electronic equipment, and especially relates to an alternating current transmission circuit. The alternating current transmission circuit includes power supply circuit and a switch circuit coupled with the power supply circuit. The switch circuit includes a main control circuit, a surge detection circuit, and a first switch device connected in series in the power supply circuit. The main control circuit is signal connected with the first switch device and configured to control on-off of the power supply circuit by controlling the first switch device. An input terminal of the surge detection circuit is connected with the power supply circuit, and an output terminal of the surge detection circuit is connected with the main control circuit.

A control device includes a triac and a first diode that is series-connected between the triac and a first terminal of the device that is configured to be connected to a cathode gate of a thyristor. A second terminal of the control device is configured to be connected to an anode of the thyristor. The triac has a gate connected to a third terminal of the device that is configured to receive a control signal. The thyristor is a component part of one or more of a rectifying bridge circuit, an in-rush current limiting circuit or a solid-state relay circuit.

Described herein are active rectification methods and systems for a rectifier of a wireless power system. Exemplary methods can include detecting, by a zero-crossing detector, one or more zero-crossings of a current at an input of the rectifier and determining a first delay time based on at least one wireless power system parameter and the zero-crossings. The methods can include generating first and second control signals for first and second switches of the rectifier, respectively, based on the first delay time; inserting a first dead time between the first control signal and the second control signal; and providing the first and second control signals to the first and second switches, respectively.

The power converter A1 includes a semiconductor device B1, and a substrate H on which the semiconductor device B1 is mounted, where the semiconductor device B1 includes a control chip constituting a primary control circuit, a semiconductor chip constituting a secondary power circuit, and a transmission circuit for electrically insulating the primary control circuit and the secondary power circuit and for signal transmission between the primary control circuit and the secondary power circuit. The substrate H has a conductive portion K. The power converter A1 includes a connecting terminal T1 disposed on the substrate H and electrically connected to the conductive portion K. The power converter A1 includes a conductive path D1 that is at least partially formed by the conductive portion K of the substrate H, and that electrically connects the primary control circuit and the connecting terminal T1. Such a configuration contributes to downsizing the power converter A1.

An integrated circuit for a power supply circuit configured to generate an output voltage of a target level from an alternating current (AC) voltage. The power supply circuit includes a first capacitor and an inductor configured to receive a voltage according to the AC voltage, and a transistor configured to control an inductor current flowing through the inductor. The integrated circuit is configured to switch the transistor, and includes: an identification circuit configured to identify whether a voltage level of an effective value of the AC voltage is a first level or a second level, and a signal output circuit configured to output a driving signal to drive the transistor, and correct the driving signal to thereby correct the input current, in response to the voltage level of the effective value being the first level and the second level, respectively.

A method and apparatus are described for controlling the gain of a phase loop of an interleaved boost converter using cycle signals. In an embodiment, a phase compensator compares a duration of the power phase of a converter to a cycle duration for the converter to generate a phase compensation. A phase adjustment module receives phase feedback signals of the first and second converters, measures the phase difference, receives the phase compensation, and generates a phase control output in response. A cycle controller receives the phase control output and generates first and second drive signals to control switching of first and second gates of the respective converters, wherein times of the first and second drive signals are adjusted using the phase control output.

This application relates to methods and apparatus for powering microcontrollers (104), in particular for powering microcontrollers of a personal care product, such as a shaver product (107). The microcontroller is arranged such that a first output port (206-1) of a plurality of output ports of the microcontroller receives, in use, an AC waveform. Each output port has an associated high-side switch (207) electrically connected between the output port and a high-side DC voltage rail and an associated low-side switch (208) electrically connected between the output port and a low-side DC voltage rail. A processing module (202) of the microcontroller is configured to monitor a phase of the AC waveform and to control switching of the associated high-side and low-side switches of the first output port based on the phase of the AC waveform so as to provide a rectified voltage between the high-side DC voltage rail and the low-side voltage rail for powering the processing module. The processing module (202) also controls switching of the associated switches of at least a further output port to output a control signal for controlling at least one aspect of operation of a host device. The processing module is further configured to maintain the associated high-side switch of the first output port in a turned-off state when a monitored voltage of the AC waveform at the first output port is between zero and a monitored voltage at the high-side DC voltage rail, and to maintain the associated high-side switch of the first output port in a turned-on state when the monitored voltage of the AC waveform at the first output port is greater than the monitored voltage at the high-side DC voltage rail.

A wireless power transfer system using a resonant rectifier circuit with capacitor sensing. A wireless power transfer system includes a power receiver resonant circuit and a synchronous rectifier. The power receiver resonant circuit includes an inductor and a capacitor connected in series with the inductor. The synchronous rectifier is configured to identify zero crossings of alternating current flowing through the inductor based on voltage across the capacitor, and control synchronous rectification of the alternating current based on timing of the zero crossings.

A power converter comprises a primary stage including four switches forming a first H bridge; a control circuit capable of applying a first control signal to the first H bridge; a secondary stage including four switches forming a second H bridge; a control circuit capable of applying a second control signal to the second H bridge; and a power transmission stage coupling the primary stage to the secondary stage, wherein the control circuit of the secondary stage is electrically isolated from the control circuit of the primary stage. During a measurement period of a synchronization phase, the switches of the secondary stage are maintained in a short-circuit configuration while the switches of the primary stage are controlled in switched mode.