摘要 |
A power supply having a two-way DC to DC converter has an AC to DC converter and a two-way DC to DC converter. When an AC power is input to the AC to DC converter, the AC to DC converter transforms the AC power to a middle level DC power and the two-way DC to DC converter transforms the middle level DC power to a low level DC power. When the AC power is unavailable and the two-way DC to DC converter obtains an external DC power, the two-way DC to DC converter transforms the external DC power to the middle level DC power. Therefore, if the power supply obtains the external DC power, the power supply can still output the middle level DC power even the AC power is unavailable. |