That’s because brushless DC motors ... Speed Control (ESC). [Fileark] built and ESC using an Arduino and has a couple of posts explaining the concept and demonstrating how it works. His test ...

En route to getting the off-the-peg DC-51 motor speed controller ... these contacts or the speed control from also shorting the 240V+Vcc rail if the max speed preset potentiometer is adjusted to 0Ω.

Prior knowledge needed: ECEA 5340 Sensors and Sensor Circuit ... AC motor control components and systems, both manual and automatic. This will culminate in training for you on AC variable speed drives ...