A first node of converter circuit receives an input, provides an output at a second node, and has a third node coupled by an inductance to ground. A first switch has a current path between the first and third nodes and a second switch has a current path between the third and second nodes. The converter circuit operates in a first state (with the first switch conductive and the second switch non-conductive) and a second state (with the first switch non-conductive and the second switch conductive). Current flowing through the first switch is sensed during the first state to produce a sensing signal indicative of inductance current. The sensing signal is averaged to produce an averaged sensing signal indicative of an average value of the current. The averaged sensing signal is then weighted by a time during which the second switch is conductive to produce a weighted signal.

The power supply apparatus alternately repeats a control between a first control of varying a frequency of switching operation within a predetermined range and for a predetermined cycle according to a frequency determined based on a feedback voltage, and a second control of varying the frequency within a range narrower than the predetermined range or a third control of controlling the frequency to be a constant frequency.

At a first node (N1), an intermediate voltage potential occurs between a voltage potential of the first input terminal (P1) and a voltage potential of the second input terminal (P2). A second node (N2) is connected to ends (b1 to b3) of primary windings (w1, w4, w7) of transformers (T1 to T3) of LLC resonant converters (11 to 13). A switch circuit is connected between the first node (N1) and the second node (N2). A control circuit (15) is configured to turn on a switch circuit (SW) when a load current of a load apparatus (6) connected to a first output terminal (P3) and a second output terminal (P4) is equal to or smaller than a predetermined criterion and turn off the switch circuit (SW) when the load current of the load apparatus (6) is larger than the predetermined criterion.

The present invention discloses a method of standby power supply including steps of: detecting a loading level; determining the loading level; entering a select mode; selecting a standby mode; entering a no-load mode, or a sleep mode, or a power-down mode; during the no-load mode, generating a no-load sustaining power, and returning back to detect the loading level when a preset condition is met; during the sleep mode, generating a sleep sustaining power, and returning back to detect the loading level when the preset condition is met; during the power-down mode, ceasing the power and entering a power-down recovery mode; and during the power-down recovery mode, returning back to detect the loading level when the preset condition is met. Therefore, the present invention implements power conversion for normal power supply, and particularly effectively controls the amount of power in the standby state, thereby greatly reducing power consumption and improving power saving.

Disclosed is a user system which includes a first device and a second device, which share a shared voltage, and a power management integrated circuit (PMIC) generating the shared voltage. An operation method of the user system includes performing a first operation of the first device, determining whether a second operation of the second device is to be performed while the first device performs the first operation, based on an operation profile, and when it is determined that the second operation of the second device is to be performed while the first device performs the first operation, changing a power mode of the PMIC from a first power mode to a second power mode, before the second device performs the second operation. The PMIC generates the shared voltage based on the first power mode or the second power mode.

A method involves determining that a power converter is in a no-load or ultra-light load mode of operation. In response to determining that the power converter is in a no-load or ultra-light load mode of operation, a voltage amplitude of a feedback signal of the power converter is allowed to rise towards a voltage amplitude that is greater than or equal to a first threshold voltage level. Upon determining that the voltage amplitude of the feedback signal is greater than or equal to the first threshold voltage level, a first sequence of enabling pulses are issued to a primary side switch of the power converter to reduce a voltage amplitude of the feedback signal. Upon determining that the voltage amplitude of the feedback signal is greater than or equal to a second threshold voltage level, a normal mode of operation of the power converter is entered.

An integrated circuit for a power supply circuit that includes a transformer including a primary coil, a secondary coil, and an auxiliary coil, and a transistor controlling a current flowing through the primary coil. The integrated circuit includes a first determination circuit determining a state of the load; a second determination circuit determining whether a current of the secondary coil is in a continuous mode and a discontinuous mode, in which the current of the secondary coil respectively does not reach, and reaches, zero when the transistor is off; an oscillator circuit outputting an oscillator signal; and a switching control circuit controlling switching of the transistor in response to a determination result of the second determination circuit and the oscillator signal, and in response to the oscillator signal irrespective of the determination result of the second determination circuit, respectively when the state of the load is light and heavy.

An energy storage device and a method thereof for supplying power are provided. Control a power conversion circuit to lower an AC output voltage during a preset period to a preset voltage, control the power conversion circuit to change from outputting the preset voltage to outputting a surge voltage, so that the power conversion circuit enters a surge generation period, and determine whether to turn off the energy storage device according to whether an output terminal of the power conversion circuit generating a surge current during the surge generation period.

In an example, a system includes a differential amplifier having a first input terminal and a second input terminal, the differential amplifier configured to be coupled to a boost diode of a boost converter. The system also includes an input diode coupled to the first input terminal and the second input terminal. The system includes a pull-up circuit coupled to the input diode and configured to be coupled to the boost diode. The system also includes a pull-down circuit coupled to the pull-up circuit. The system includes a transistor coupled to the pull-up circuit and the pull-down circuit.

A power convertor configured to output power to an electrofusion welding coupler for performing electrofusion welding. The power convertor comprises an array of connected DC to DC power convertor circuits. In use, the array of connected DC to DC power convertor circuits is configured to receive, at a first interface, power at a first voltage level from a battery and output power, at a second interface, at a second voltage level to provide power to electrofusion welding cable means. The DC to DC power convertors are arranged in a buck-boost configuration which can operate in a boost mode in which the first voltage level is less than the second voltage level and in a buck mode in which the first voltage level is greater than the second voltage level.