US Patent 7589964 Power supply apparatus

A power supply apparatus for use with a redundant power supply system includes a casing, a main circuit board and an airflow driving device. The casing includes a first airflow opening and a second airflow opening. The main circuit board is disposed within the casing and includes plural electronic components thereon. The airflow driving device is disposed in the middle region of the main circuit board. A cooling air is pumped by the airflow driving device to be introduced into the inner portion of the casing through one of the first airflow opening and the second airflow opening, then the heat generated from the electronic components is removed by the cooling air, and finally a heated air is exhausted through the other one of the first airflow opening and the second airflow opening.