This circuit will double almost any DC input voltage as well as handling plenty of current. 12 to 24V is just an example. With a few changes, it can also supply any desired output voltage.
There are many possible applications. One I can think of would be to get the 28V for the ADC connector on Gigabit Ethernet and later Power Macintosh G4s from the +12V on a standard PC ATX power supply. Basically any time you need more voltage than what you’ve got. Possibly on camping trips when you need 12-14 volts but only have 6V cells. Also you can use it to boost the cooling power of the fans in your computer if they can handle the extra voltage. Some can’t. Keep reading for more on this. What I use it for is to increase the speed and thus the airflow of a standard 80mm DC brushless fan.
Read More Source:
http://kickme.to/lightningstalker
http://www.elecfree.com/electronic/12v-to-24vdc-voltage-booster/
