The Dimension Engineering AnyVolt 3 Universal DC-DC Converter is an adjustable step up/step down 3A switching regulator.
The Dimension Engineering AnyVolt is a pretty solid DC-DC converter that will take any voltage from 5 to 30V and turn it into 3 to 24V (at up to 3A, if your supply can source it). Yes, there are other DC-DC converters, but none this affordable with this performance!
Set your desired output with a small screw potentiometer on the back of the AnyVolt 3. Once set, it does not matter whether input voltage is higher, lower, or the same as the desired output. The potential applications are endless and only limited by the unit's specifications and your collection of gadgets that require DC power at a different voltage than their supply.
Input power and output loads are connected with reusable screw terminals, so no soldering is necessary.