A drive circuit includes a second drive circuit that drives a semiconductor switching element in a case where a pulse width of a corresponding signal is determined to be larger than a second threshold, and a timing adjustment circuit that adjusts a timing at which the second drive circuit cooperates with a first drive circuit to drive the semiconductor switching element during a turn-off period of the semiconductor switching element due to drive of the first drive circuit.

Synchronous rectification control circuit and switching power supply system are provided. The circuit includes a sampling circuit, a turn-on comparison circuit, a turn-off comparison circuit, a drive control circuit, an anti-accidental turn-on circuit, wherein the sampling circuit has a first terminal coupled to a first output terminal of a transformer; the anti-accidental turn-on circuit has a first input terminal coupled to a second terminal of the sampling circuit; the turn-on comparison circuit has a first input terminal coupled to the second terminal of the sampling circuit, a second input terminal coupled to an output terminal of the anti-accidental turn-on circuit; the turn-off comparison circuit has an input terminal coupled to the second terminal of the sampling circuit; the drive control circuit has a first input terminal coupled to an output terminal of the turn-on comparison circuit, a second input terminal coupled to an output terminal of the turn-off comparison circuit.

A system for turning off a synchronous rectifier (SR) based on a primary switch (PS) turn-on detection in a flyback converter having a primary-side and a secondary-side is disclosed. The system comprises the PS on the primary-side, the SR on the secondary-side, a spike detector, and a SR controller. The SR is configured to produce a drain-to-source voltage (V.sub.DS). The spike detector is in signal communication with an output capacitor (C.sub.out) on the secondary-side and the spike detector is configured to detect a voltage spike of an output voltage (V.sub.Out) across the C.sub.out that is indicative of the PS being turned-on. The SR controller is in signal communication with the SR and the spike detector and the SR controller is configured to turn-off the SR based on the spike detector detecting the voltage spike of the V.sub.Out.

A control circuit for a switching converter, where: in a first operation state, the control circuit controls a switching period of the switching converter to remain unchanged, controls a turn-on time of a power transistor in the switching converter to be not less than a minimum turn-on time in each switching period, and controls a turn-off time of the power transistor to be not less than a minimum turn-off time; in a second operation state, the control circuit controls the turn-on time of the power transistor to be the minimum turn-on time in each switching period, and adjusts the switching period to further reduce a duty cycle; and in a third operation state, the control circuit controls the turn-off time of the power transistor to be the minimum turn-off time in each switching period, and adjusts the switching period to further increase the duty cycle.

The invention relates to a switching power supply converter, which comprising a transformer including a primary winding and a secondary winding, a power switch circuit and a voltage input circuit, a voltage output circuit, an auxiliary winding, a control circuit, and a voltage sensing circuit; the control circuit performs that in a first turn-off period of the power switch circuit, acquiring a first time duration from a preset delay after the power switch circuit turning off until the sensed voltage corresponding to a preset condition, and acquiring a difference between the first time duration and a preset time duration as a second time duration; in a second turn-off period of the power switch circuit, acquiring the sensed voltage at the time point corresponding to the end of the second time duration starting from the preset delay after the power switch circuit turning off as an effective sample.

A power device is provided. The power device includes a current limiting resistor in series with a load, the current limiting resistor configured to provide a first current path to the load. The power device also includes an inrush current control device configured to provide a second current path to the load, the second current path configured to bypass the first current path in response to the inrush current control device being activated. The power device also includes a bypass device configured to provide a third current path to the load, the third current path configured to provide a low-resistance current path to the load during a power surge.

A power supply for providing an electric pulse to an electrical consumer is shown. The power supply has an input circuit, a storage capacitor, and an output circuit. The input circuit is configured to charge the storage capacitor up to a maximum voltage. The output circuit is configured to provide one or more pulses having a pulse voltage on the basis of a charge stored in the storage capacitor and to compensate for a reduction of the voltage of the storage capacitor by at least 30% down from the maximum voltage. Moreover, the power supply is configured such that the voltage of the storage capacitor is reduced by at least 30% during the generation of one or more pulses.

A power transmission device includes a transmission coil that supplies power to a power reception device, a power supply circuit that converts DC power supplied from a DC power source via a plurality of switching elements connected in a full bridge shape or a half bridge shape between DC power sources and the transmission coil into AC power and supplies the AC power to the transmission coil, a phase adjustment circuit having an LC series circuit connected in parallel with the transmission coil and a switching element connected in series with the LC series circuit, and a control circuit that controls switching on and off of the switching element of the phase adjustment circuit in accordance with a measured value of an amount of current when any of the plurality of switching elements of the power supply circuit is turned off by a current detection circuit.

A DC-DC boost converter includes an inductor coupled between an input voltage and an input node, a first path coupled between the input node and a first output node at which a first output voltage is generated, and a second path coupled between the input node and a second output node at which a second output voltage is generated. The DC-DC boost converter operates in a first operating phase where the first path boosts the first output voltage and where the second path is kept from boosting the second output voltage by the second path being coupled to the first path, and operates in a second operating phase where the second path boosts the second output voltage and where the first path is kept from boosting the first output voltage by the second path not being coupled to the first path.

A system and method for controlling a power module are provided. The system includes a switch element that adjusts output of a power module, a driving signal generation unit that generates a switch ON signal and a switch OFF signal for the switch element, and a latch that is connected between the driving signal generation unit and the switch element and is configured to delay the switch ON signal generated by the driving signal generation unit by a preset delay time and transfer a delayed signal to the switch element. Additionally, a compensation unit is connected between the latch and the power module and is configured to adjust the output of the power module during the delay time by which the latch delays the switch ON signal.