Power supply device for varying an output voltage

摘要

A power supply device includes an output port, a transformer, a power switch, a current sensor, a voltage-dividing controller, a voltage-feedback unit, a voltage comparator, a main controller, and a pulse width modulator. The transformer has two inductances. The power switch is electrically connected to a primary winding of the transformer, the pulse width modulator, and the current sensor coupled to the voltage-dividing controller. The voltage-feedback unit is electrically connected to the voltage-dividing controller, the voltage comparator, and the output port. The main controller is coupled to the pulse width modulator and the voltage comparator.

主权项

1. A power supply device electrically comprising an output port electrically connected to an electronic product, the power supply device comprising:
a power source; a transformer comprising a primary winding and a secondary winding coupled with each other, the primary winding electrically connected to the power source, and the secondary winding electrically connected to the output port, wherein the transformer having a first inductance and a second inductance smaller than the first inductance; a power switch electrically connected to the primary winding and the power source; a current sensor electrically connected to the power switch; a voltage-dividing controller electrically connected to the current sensor, wherein the voltage-diving controller comprises a light-generating component and a light-receiving component, the light-generating component is electrically connected to the current sensor, and the light-receiving component is electrically connected to the voltage-feedback unit; a voltage-feedback unit coupled to the voltage-diving controller and the output port; a voltage comparator electrically connected to the voltage-feedback unit; a main controller electrically connected to the voltage comparator; and a pulse width modulator electrically connected to the power switch and the main controller, wherein the current sensor senses a current flowing through the primary winding to make the voltage-dividing controller generate a voltage-dividing-controlling signal for regulating a voltage outputted from the voltage-feedback unit, and the voltage comparator compares a potential level of the regulated voltage with a preset potential level, to generate a compared signal for modulating a duty cycle of the pulse width modulating signal outputted from the pulse width modulator, thus an output voltage from the output port is regulated.