A bleeder current control method. The bleeder current control method includes the following steps: The rectifier bridge transmits a post-bridge input signal to the power system. The shaping circuit obtains the post-bridge input signal and shapes it into a bleeder current reference signal, the bleeder current reference signal is inversely correlated with the initial post-bridge input signal. Acquiring a current sampling signal representing the bleeder current, and comparing the error of the current sampling signal with the bleeder current reference signal to obtain an error signal. The current sampling signal is controlled according to the error signal, so that the current sampling signal is output based on the waveform of the bleeder current reference signal. Thus, a reliable and full-time sine wave envelope signal is provided to the power system, so as to reduce the loss caused by the bleeder current to the power system.

A vehicle-mounted power supply system includes a sampling circuit, a voltage comparison control circuit, a power conversion circuit, and a motor. The sampling circuit is configured to obtain an output voltage value of an output terminal of the power conversion circuit. The voltage comparison control circuit is configured to output a first power adjustment signal to the power conversion circuit when the output voltage value is less than a first target voltage value. The power conversion circuit is configured to increase an output voltage to a first target voltage based on the first power adjustment signal, to output the output voltage to the motor and increase an input voltage of the motor. When a voltage of a power supply is low, the input voltage of the motor can be maintained at a required level.

There is provided a high frequency AC inverter comprising a DC-DC circuit, an output power circuit and a load circuit and a controller, the load circuit comprising a load circuit detector configured to detect the electrical parameters of the load circuit. The output power circuit comprises a DC to AC driver having a variable frequency output, a HFAC driver circuit comprising a resonant network and a transformer coupled to the HFAC driver circuit and the load circuit. The controller is configured to control the output frequency of the DC to AC driver and the output of the DC to DC circuit in response to the detected electrical parameters of the load circuit.

A bridge converter converts an input voltage into an output voltage, and includes a switching circuit, a transformer, a rectifying circuit, and a control module. The switching circuit includes a first switch and a second switch. The control module sets a first time period and a second time period. The control module provides a first control signal and a second control signal to control the switching circuit based on the output voltage. The control module fixes an operation frequency of the first control signal and the second control signal at the maximum frequency based on that the control module is set in a standby mode, and provides the first control signal and the second control signal in the first time period, and shields the first control signal and the second control signal in the second time period.

An electronic apparatus includes: an operator; and a power circuit configured to supply power to the operator, wherein the power circuit includes a first voltage converter configured to output a first voltage based on input power, and a power factor corrector (PFC) configured to output a second voltage by performing power factor correction for the first voltage, and supplies power based on the first voltage or the second voltage to the operator, wherein the power circuit stops an operation of the PFC, lowers the first voltage to have a level corresponding to the second voltage, and supplies power based on the lowered first voltage to the operator, based on power consumption of the operator lower than or equal to a predetermined value.

A converter operable to convert an input voltage at an input node to an output voltage at an output node coupled to a load by switching on and off a transistor at a switching frequency, the converter comprising: an error amplifier circuit having a first input coupled to a reference voltage, a second input coupled to the output node through a resistive divider, a first output operable to output a control current and a second output operable to output a current equivalent to the control current; a peak current comparator circuit having a first input coupled to the second output of the error amplifier circuit, a second input and an output, the second input is coupled to the input node through an inductor; an off-time timer circuit having an input coupled to the first output of the error amplifier circuit and an output, the off-time timer circuit operable to set the switching frequency based on the control current; and a control circuit having a first input coupled to the output of the peak current comparator circuit, a second input coupled to the output of the off-time timer circuit and an output coupled to a control terminal of the transistor.

The present disclosure provides a power factor improvement circuit with a DC/DC converter including an arithmetic circuit. A first voltage having a full-wave rectified waveform is received by an input voltage detection terminal of the power factor improvement circuit. A second voltage is generated by amplifying an error between a first detection voltage and a reference voltage according to an output voltage of the DC/DC converter. A third voltage is generated by multiplying the first voltage by the second voltage. The arithmetic circuit adds an offset voltage to a third voltage to generate a fourth voltage. A comparator is configured to compare a second detection voltage with the fourth voltage. A drive circuit is configured to turn on/off drive of the switching transistor according to an output of the comparator. When the second detection voltage is higher than the fourth voltage, the switching transistor is turned off.

Techniques and apparatus for current-based transitioning between a buck converter mode and a charge pump mode in an adaptive combination power supply circuit. One example power supply circuit generally includes a switching regulator and control logic coupled to the switching regulator. The control logic is generally configured to compare an indication of a current associated with the switching regulator to a threshold and to control a transition of the switching regulator between a buck converter mode and a charge pump mode based on the comparison.

An architecture for a multi-port AC/DC Switching Mode Power Supply (SMPS) with Power Factor Correction (PFC) comprises power management control (PMC) for PFC On/Off Control and Smart Power Distribution, and optionally, a boost follower circuit. For example, in a universal AC/DC multi-port USB-C Power Delivery (PD) adapter, PMC enables turn-on and turn-off of PFC dependent on output port operational status and a combined load of active output ports. A microprocessor control unit (MCU) receives operational status, a voltage sense input and a current sense input for each USB port, computes output power for each USB port, and executes a power distribution protocol to turn-on or turn-off PFC dependent on the combined load from each USB port. Available power may be distributed intelligently to one or more ports, dependent on load. In an example embodiment, turning-off PFC for low load and low AC line input increases efficiency by 3% to 5%.

A power supply includes an inverter configured to direct current (DC) power into alternating current (AC) power, an impedance matching circuit configured to supply the AC power to a load; and a controller configured to adjust disposition of a powering period, in which the AC power is output, and a freewheeling period, in which the AC power is not output, to adjust a power amount of the power supplied to the load through the impedance matching circuit by the inverter.