A power switching converter includes a switch coupled to an input terminal through a primary winding of a transformer and a control circuit configured to drive the switch to provide a regulated output signal at a secondary winding of the transformer. A wake up circuit is provided to force the switching-on of the switch when the power converter enters in a burst mode. The wake up circuit includes a transmitting section coupled to the secondary winding and a receiving section coupled to an auxiliary winding of the transformer and the control circuit. The transmitting section is configured to provide a wake up signal communicated in a wireless manner to the receiving section when the output signal falls below a threshold value.

An uninterruptible power supply for providing an output power signal to a load has a ferroresonant transformer, a resonant capacitor operatively connected to the ferroresonant transformer, and an inverter operatively connected to the ferroresonant transformer. The inverter is configured to generate the output power signal based on at least one inverter control signal such that the output power signal is a quasi square wave having a first change of phase, an upper limit, and a second change of phase. The at least one inverter control signal is pulse-width modulated between the first change of phase and the upper limit, pulse-width modulated between the upper limit and the second change of phase, and held in an ON state when the output power signal is at the upper limit.

The present disclosure relates to a circuit structure for enhancing EFT immunity of primary side converter, including a power ground and a feedback voltage detecting block, a feedback current detecting block, a controller, a PWM driving block, a high voltage starting block, a starting unit, a circuit for enhancing EFT immunity of primary side converter, a power MOS transistor, and an OR gate configured to perform a logical OR of an off-time calculated theoretically and an off-time output by an off-time control block. The present disclosure enhances EFT immunity effectively and improves the dynamic characteristics of the primary side converter.

In accordance with an embodiment, a method of controlling a switched-mode power supply includes operating the switched-mode power supply in a first operating mode by monitoring a feedback signal from an output of the power supply using a feedback interface circuit in a first configuration. The method further includes determining when the feedback signal crosses a first threshold in a first direction, and transitioning the switched-mode power from the first operating to a second operating mode by switching the feedback interface circuit from the first configuration to a second configuration.

A switching power supply comprises a transformer; a switching element; a power supply control section which outputs a first gate voltage of a first pulse width consecutively for plural times when the switching element is driven in a burst mode in which the switching element is intermittently driven; a drive time control section which, based on the first gate voltage input consecutively for plural times when the switching element is driven, outputs a second gate voltage to the switching element consecutively for plural times and gradually increases a pulse width of the second gate voltage to a first pulse width from a second pulse width narrower than the first pulse width; and a switching section to which a feedback voltage is input which switches an input destination of the first gate voltage output by the power supply control section from the switching element to the drive time control section in the burst mode.

A method and an apparatus for transferring electric power to an electrical load (105); the method includes steps of: converting a direct electric current into an electric tension wave, applying the electric tension wave in inlet to at least a couple of electric capacitors (125, 130); supplying the electrical load (105) with the electric tension in outlet from the capacitors (125, 130).

A control circuit, a power supply including a control circuit, and a method are disclosed. The control circuit is configured to activate a second output capacitor connected in parallel with a first output capacitor of a power supply when the power supply is in a normal operating mode, and deactivate the second output capacitor when the power supply is in a standby mode.

Various embodiments relate to a power converter including a resonant converter with an controller, the controller configured to control the converter to operate in a normal mode when output power is above a burst mode threshold level, start a timer when the output power falls below the burst mode threshold level, continue operating in the normal mode until the timer reaches a predetermined time and operate in burst mode when the timer reaches the predetermined time.

A control signal generator includes an error amplifier, a first comparator, a second comparator, a logic circuit and a pulse generator. The error amplifier has a first output, a first input, a second input and a first snooze input. The first comparator has a second output, a third input and a fourth input. The third input is coupled to the first output. The second comparator has a third output, a fifth input, a sixth input and a second snooze input. The fifth input is coupled to the third input. The logic circuit has a fourth output and logic circuit inputs, including a first logic circuit input coupled to the second output. The pulse generator has a fifth output and a seventh input. The seventh input is coupled to the fourth output. A snooze mode controller has a sixth output coupled to the first snooze input and the second snooze input.

A power supply device includes a rectification circuit that is supplied with AC power from an AC power supply, a power factor improvement circuit that boosts an output voltage of the rectification circuit, smooths a boosted voltage with a capacitor, and thereby generates a DC output voltage outputted to a load circuit, a DC-DC converter that steps down the DC output voltage to a prescribed first voltage, a DC output voltage detection circuit that detects whether or not the DC output voltage satisfies a prescribed condition, and a switch circuit that temporarily puts the power factor improvement circuit in an operating state by use of the first voltage each time the prescribed condition is satisfied in a period in which the power factor improvement circuit is in a stopped state due to an energy saving mode of the load circuit.