If you want to power a darling single board computer, but you have only a higher voltage power source at hand, this linear regulator will do the trick. This converter from the Troyka Module series will help power modules with 3.3-volt logic.
The regulator takes an input voltage from 4.4 to 20 V and converts it to 3.3 V. The remaining power is dissipated as heat. The module itself acts as a radiator.
The use of a linear transducer simplifies the design of the device and eliminates interference which means you can use this to power sensitive sensors.
The terminal blocks for external power supply and load are soldered on the module:
The input and output voltages are switched on Troyka contacts by installing the appropriate jumpers.