Abstract:
An LED driver of an LED tube includes: an AC-to-DC converting module converting an AC voltage received from a ballast into an intermediate DC voltage that is smaller than or equal to a predetermined threshold voltage, and a DC-to-DC converting module converting the intermediate DC voltage into a DC output voltage for driving LEDs of the LED tube.
Abstract:
An energy management system includes a power supply module, a charging module, an interface module and an energy management module. The power supply module provides an input power. The charging module generates, based on the input power, a first charge power and a second charge power in response to a first charge control signal and a second charge control signal. The interface module detects electrical energy stored in an energy storage device to generate a detection result. In response to the detection result, the energy management module determines an operating state of the energy storage device, and generates one of the first and second charge control signals.
Abstract:
An interleaved buck converter performs buck conversion by controlling operation of each of two switches thereof between an ON state and an OFF state. The switches have the same switching period and the same ON time interval, and a time delay from switching of one of the switches into the ON state to switching of the other one of the switches into the ON state equals the ON time interval of the switches minus a predetermined time interval.
Abstract:
A power converting device includes a main switch, a synchronous rectifier switch, a rectifier-filter circuit which outputs an output voltage, and a synchronous rectifier control circuit which includes a sampling circuit coupled to the rectifier-filter circuit for outputting a voltage variation signal, a differential amplifier circuit that outputs an amplified signal by adding the output voltage and an offset voltage to the voltage variation signal attenuated thereby, and a comparison circuit that compares the amplified signal with the output voltage so as to output a trigger signal, such that the synchronous rectifier switch is turned on when the main switch is turned off, and is turned off prior to conduction of the main switch.
Abstract:
A flyback converter includes: a transformer including a primary winding and a secondary winding; a first switch coupled to the primary winding; a first control module configured to control the first switch; a second switch coupled to the secondary winding; and a second control module configured to control the second switch, such that the second switch operates in an ON state during a first time period and during a second time period which follows the first time period, and such that a current flowing through the secondary winding has a direction during the second time period opposite to that during the first time period.
Abstract:
A buck converter includes: a first input terminal; a second input terminal; a first output terminal; a second output terminal; an internal node; a first inductor, a second inductor and a main switch connected in series between the first input terminal and the internal node; a third inductor connected between the internal node and the first output terminal; a fourth inductor connected between the second input terminal and the second output terminal; a first auxiliary switch connected between the internal node and the second output terminal; and a second auxiliary switch connected between the second input terminal and the first output terminal.
Abstract:
A voltage control method for a power converter includes: acquiring a current of a first primary side winding of a transformer circuit of the power converter; integrating the acquired current to obtain an average voltage; comparing the average voltage with a reflected voltage associated with a current of a secondary side winding of the transformer circuit; and adjusting a duty cycle of a switch of the power converter based on an obtained comparison result for adjustment of an output voltage of the power converter.
Abstract:
A power converting device includes a transformer, a first switch coupled to a primary winding of the transformer, a PWM controller which generates a first PWM signal for controlling conduction and non-conduction of the first switch and which generates a control signal that leads the first PWM signal, a rectifier-filter circuit which rectifies an induced voltage generated by a secondary winding of the transformer, a second switch coupled to the secondary winding, and a synchronous rectifier controller which controls conduction and non-conduction of the second switch, and which controls, according to the control signal, the second switch to become non-conductive prior to conduction of the first switch.
Abstract:
A power supply apparatus includes a switch, a converting module and a control module. When the switch operates in an ON state, an input voltage is outputted through the switch to serve as an output voltage. The converting module selectively converts the input voltage into the output voltage. When the power supply apparatus operates in a mode where the switch operates in an OFF state, where the converting module performs the conversion, and where the output voltage is stabilized at a target voltage value, and when a condition associated with the input voltage is met, the control module causes the output voltage to gradually change toward the input voltage.
Abstract:
A single-stage AC-to-DC converter includes a bus capacitor, a power factor correcting module, a resonant converting module and a control module. The power factor correcting module generates, based on an AC (alternating current) input voltage, a first control signal and a second control signal, a DC (direct current) bus voltage across the bus capacitor and an intermediate voltage switching between the bus voltage and zero. The resonant converting module generates a DC output voltage based on the intermediate voltage. The control module generates, based on the bus voltage, the first and second control signals, each of which switches between an active state and an inactive state and has a duty cycle associated with the bus voltage.