A power supply apparatus includes a DC-to-DC converter performing a voltage conversion converting a voltage of a source power supplied from a direct current power source to a first predetermined voltage lower than the voltage of the source power and a voltage regulator carrying out a voltage regulation...http://www.google.de/patents/US6713992?utm_source=gb-gplus-sharePatent US6713992 - Method and apparatus for power supply capable of effectively reducing a power consumption
