Power supply device and method of controlling the same

A method for controlling a power supply device comprising a power factor corrector which corrects a power factor of initial power, and a standby power supply unit which is connected to the power factor corrector and comprises a transformer to convert a received input power to a predetermined level of a standby power and supply a driving power to a system, the method comprising:

• detecting a level of an induced power corresponding to the input power;
• determining whether the level of the induced power exceeds a critical value when a system-on signal is received;
• activating the power factor corrector if the level of the induced power exceeds the critical value;
• and
• supplying the driving power to the system based on the level of the induced power detected after the power factor corrector is activated.

A power supply device comprising:

• a power factor corrector which is coupled to a source of an initial power, and corrects a power factor of the initial power to output a corrected input power;
• and
• a standby power supply unit which is connected to the power factor corrector, and selectively receives one of the initial power or the corrected input power, the standby power supply unit comprising:
• a transformer which converts one of the received initial power and the corrected input power and comprises first and second coils;
• a sensor which is coupled to the second coil and induces an induced power in the second coil corresponding to a level of one of the received initial power and the corrected input power;
• and
• a power supply controller which determines whether the level of the induced power exceeds a critical value when a system-on signal is received, activates the power factor corrector to correct the power factor of the initial power and supply the corrected input power to the standby power supply unit if the level of the induced power exceeds the critical value, and supplies a driving power to the system based on the level of the induced power detected after the power factor corrector is activated.