Power supply and method of operating the same

A power supply comprising:

• a main power supply configured to receive external power and output charge voltage and main power;
• and
• an auxiliary power supply including a capacitor array configured to charge auxiliary power using the charge voltage and output the auxiliary power,
• wherein the auxiliary power supply is configured to check a detected voltage charged in the capacitor array until a charging level of the capacitor array reaches a target level, and periodically repeat a discharge operation and a sub charge operation on the capacitor array.

A method of operating a power supply, the method comprising:

• supplying an auxiliary power to capacitors through a charge line;
• and
• periodically performing a monitoring operation on the charge line while a charging level of the plurality of capacitors is increased to a target level,
• wherein the monitoring operation comprises:
• decreasing a voltage of the charge line;
• and
• charging the charge line.