I'm trying to build my own quadcopter and I plan to design my own flight controller / mother board. Now my question is, how do drones, such as the DJI phantom, reduce a high voltage with high current, like 11.1V 5000mah, to a more usable voltage, such as 3V, for the controller, yet still distribute the a maximum number of power.

  • Is the power pin of the ESC connected directly to the main supply?
  • Do they use a step-down converter to lower the main voltage to a more usable voltage for the microcontroller?
  • How do I calculate how big does my traces on the PCB needs to be?

1 Answer 1


Typically the ESC draws power directly from the main supply battery. To do anything else would be a gross waste of power and payload.

Many ESC have built-in "battery-eliminators", i.e. a lower voltage output specifically designed to power the electronics (receiver, controller, etc.)

There are formulae for calculating track-width depending on current capacity and temperature rise. Note also that PC boards are available with copper of different thickness. High-current boards would seem more likely to use 2oz copper than the more common 1oz copper thickness.

Google for: pcb trace width calculator


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