🔋 ESC
Electronic Speed Control — the module that takes the receiver signal and drives the motor.
Handles forward/brake/reverse, has a low-voltage cutoff to protect the pack, and often includes a BEC to power the receiver.
What it actually does
The Electronic Speed Control sits between the battery and the motor and decides how much power reaches it. It reads the throttle signal from the receiver and converts battery voltage into the rapid switching that drives the motor — it is the component that turns a stick movement into speed.
In practice
ESCs are rated by current handling and by the cell count they accept, and both need to comfortably exceed what your motor and battery will ask for. Most also carry a BEC to power the receiver and servo, low-voltage cutoff, and thermal protection that backs power off when the ESC gets too hot.
Worth knowing
Airflow and gearing matter more than the sticker rating. An ESC well within its ratings will still shut down if it is buried under a sealed body with over-aggressive gearing.