S1 - Input power switch

U1 - Adjustable Voltage Regulator

D1 - Allows connection of power input in any direction. No worries about which side is positive. Also allows for AC wall warts.

P1 - Alows for connection of any wall wart, just cut, strip and connect. Three pin are shown here but part should be two pos.

J1 - Standard 2.1mm DC power jack common on most wall warts.

C3 - Decoupling Cap

C1 - Input decoupling Cap. Allows for AC input. DC input only could use much smaller value.

C2

R1 SelA for 9V supply

R1 SelA for 6V supply

R1 SelA for 5V supply

R1 SelA for 3V or 3.3V supply

R2 SelB for 9V or 6V supply

R2 SelB for 5V supply

R2 SelB for 3V supply

R2 SelB for 3.3V supply

J2, J3, J5 and J6

J4 Ground Testpoint