The speed controller - Electronic Speed Controllers - takes orders from the control unit in the heart of the plane - Flight Control - by increasing or decreasing the flow of current for each plane's engine, which in turn works to rationalize direct energy taken from the plane's battery because each engine has a special capacity to receive Amount of Volts Because increasing the volt quantity will damage the engine once the power is connected.
Sources :
Electronic Speed Controllers: http://pirofliprc.com/Spedix-IS30-4-in-1-2-4S-LiPo-DShot600-BLHeliS-30A-ESC_p_3953.html