This design idea reprises another “ 1A, 20V, PWM controlled current source.” Like the earlier circuit, this design integrates an LM3x7 adjustable regulator with a PWM DAC to make a programmable 20 V, ...

RC receivers are 5 VDC and draw very little current, so it’s even possible to power the whole arrangement from the USB port. On the software side, the Arduino sketch does about what you expect.

This article explores several approaches for using FETs in voltage controlled circuits.