Moreover, it is easily possible with switching power supplies to obtain higher voltages than the input voltage (Step Up controller), or even a negative output voltage to generate.
Here are some links to switching power supplies
Here you will find Schematic Circuit Diagram for DIY and further information on Switching Power Supplies
|Low Voltage Step-Down Regulator, 3.3 V to 1.2 V up to 1A. Very well
|Small effective switching power supply, depending on input voltage 5-40V 2.5 A||www.kreatives-chaos.com/index.php?seite=schaltnetzteil|