A power supply used to convert an input voltage into an output voltage, and the power supply includes an input detection circuit, a conversion circuit, a detection circuit, and a controller. The input detection circuit provides a power good signal or a power fail signal according to the input voltage. The conversion circuit converts the input voltage into an output voltage, and the detection circuit detects the output voltage according to the power good signal to accordingly provide an output feedback signal with a first feedback value. The controller stabilizes a voltage level of the output voltage according to the first feedback value. The detection circuit self-adjusts a feedback condition according to the power fail signal, and correspondingly adjusts the output feedback signal to a second feedback value according to the feedback condition. The controller reduces the voltage level of the output voltage according to the second feedback value.

Optical amplification apparatus (1) for a submarine optical amplifier (90), the optical amplification apparatus (1) comprising an optical amplification system (2), comprising at least one active component (3), and a DC/DC converter (4) connected to supply the optical amplification system (2), wherein the DC/DC converter (4) comprises a first commutator (5) and a pulse modulator (6) connected to the first commutator (5) for cyclically switching with a duty cycle the first commutator (5) between a closing configuration, in which it can be passed thought by a current, and an opening configuration, in which it cannot be passed thought by the current, characterized in that the DC/DC converter (4) comprises a retroaction circuit (7) comprising, a first differential amplifier (8) connected for receiving, at a first input port, a first signal (100) representative of at least a voltage at output from the DC/DC converter (4) and at input into the optical amplification system (2) and, at a second input port, a first reference signal (201), the first differential amplifier (8) being structured for generating a first error signal (101) representative of a difference between the first signal (100) and the first reference signal (201), a second differential amplifier (9) connected to the first differential amplifier (8) for receiving, at a first respective input port, the first error signal (101) and, at a second respective input port, a second reference signal (201), the second differential amplifier (9) being structured for generating a second error signal (102) representative of a difference between the first error signal (101) and the second reference signal (201), wherein the second error signal (102) is proportional to a deviation of the voltage at output from the DC/DC converter (4) with respect to a nominal working voltage of the optical amplification system (2), in that the first input port of the first differential amplifier (8) and the first respective input port of the second differential amplifier (9) are concordant ports, and in that the pulse modulator (6) is connected to the second differential amplifier (9) for receiving the second error signal (102) and for regulating the duty cycle as a function of the second error signal (102).

One example includes a differential amplifier, a voltage weighting element, coupled to a voltage source which provides an input voltage, to provide a reference voltage with a constant power limit when the input voltage varies, an error amplifier configured to receive and compare the reference voltage provided from the voltage weighting element and a feedback sensed voltage provided from the differential amplifier to identify whether the sensed voltage exceeds the reference voltage, and a pulse width modulation (PWM) controller, coupled to a power transformer and the error amplifier, that reduces a transformer input current provided to the power transformer based on the comparison of the reference voltage from the voltage weighting element and the feedback sensed voltage from the differential amplifier.

Embodiments of a power converter are disclosed. In an embodiment, the power converter comprises a power factor correction (PFC) stage circuit, an emulation circuit and a controller. The PFC stage circuit is configured to produce an output signal on an output terminal. The PFC stage circuit includes an inductor coupled between a rectifier and the output terminal and a switch coupled to the inductor. The emulation circuit is connected to the PFC stage circuit to generate an emulated current that corresponds to current through the inductor of the PFC stage circuit. The emulated current is generated based on a voltage signal at a node between the inductor and the output terminal and a sensed current at a sense resistor connected to the rectifier. The controller is connected to the emulation circuit to receive the emulated current and generate a control signal for the switch of the PFC stage circuit based on the emulated current.

The present document relates to a power converter configured to generate an output voltage at an output of the power converter. The power converter may comprise a power stage, a modulator circuit, ramp generator circuit, a first feedback circuit, and a second feedback circuit. The power stage may be coupled to the output of the power converter. The modulator circuit may comprise a first input and a second input, and an output of the modulator circuit may be coupled to the power stage. The ramp generator circuit may be configured to generate a ramp signal, and an output of the ramp generator circuit may be coupled to the first input of the modulator circuit. The first feedback loop may be coupled between the output of the power converter and the second input of the modulator circuit.

Controller and method for a power converter. For example, a controller for a power converter includes: a feedback detector configured to receive a feedback voltage, sample the feedback voltage, and generate a sampled voltage based at least in part on the feedback voltage, the sampled voltage being associated with one or more fluctuations in magnitude; a resistor selector configured to receive the sampled voltage and generate one or more control signals based at least in part on the one or more fluctuations associated with the sampled voltage; a variable resistor network configured to receive the one or more control signals, determine a network resistance based at least in part on the one or more control signals, and output a compensation voltage based at least in part on the network resistance; and a voltage generator connected to the variable resistor network and configured to receive the compensation voltage.

A power supply apparatus including a switching element configured to supply or cut off electric power to a primary coil of a transformer by a switching operation, and a control unit configured to control the switching operation. The control unit is configured to perform intermittent control of repeating a switching period for performing the switching operation and a stop period for stopping the switching operation. In the switching period, when the control unit performs the switching operation a predetermined number of times, the switching period is transitioned to the stop period. In the stop period, when the control unit determines that a voltage output from a secondary coil of the transformer falls below a target voltage, the stop period is transitioned to the switching period. The control unit is configured to change the switching operation based on a length of the stop period.

A synchronous average harmonic current controller for a line connected bidirectional resonant power converter results in a harmonic voltage gain closely related to the commanded bridge duty cycles. A primary bridge has its duty cycle set to achieve controlled line power transfer and voltage regulation of a primary bus energy storage capacitor. A secondary bridge circuit has its duty cycle set to achieve voltage regulation of secondary bus energy storage capacitor. A first embodiment uses the independent energy storage elements to achieve power factor correction and low noise regulation using a single stage. A second embodiment uses feedforward duty cycle control to achieve isolated voltage regulation using the well-defined voltage gain resulting from the synchronous average harmonic current controller.

A method for controlling the input voltage frequency of a DC-DC converter includes calculating a control frequency value of the DC-DC converter. If the measured voltage is greater than the upper voltage limit, the control frequency corresponds to the minimum control frequency. If the measured voltage is less than the lower voltage limit, the control frequency corresponds to the maximum control frequency. If the measured voltage is between the upper voltage limit and the lower voltage limit, the control frequency corresponds to an average frequency calculated as a function of the difference between the setpoint voltage value and the measured voltage, upper error values and lower error values, and maximum and minimum control frequency values.

An apparatus includes a buck-boost converter comprising a buck portion and a boost portion connected in cascade, and a controller comprising a first timer and a second timer, wherein the first timer is configured to determine a turn-on time of a high-side switch of the buck portion, and wherein the first timer determines the turn-on time of the high-side switch of the buck portion based on a comparison between a first signal and a second signal, and wherein the first signal is proportional to an output voltage of the buck-boost converter and the second signal is generated based on a signal proportional to an input voltage of the buck-boost converter, and the second timer is configured to determine a turn-on time of a low-side switch of the boost portion.