An ESC is a device that controls the speed of a brushless electric motor in an RC vehicle. It works by taking the input from a receiver, which is connected to a radio transmitter, and using that input to control the amount of power that the motor receives.

The ESC has three main components: the power wires, the control wires, and the microcontroller. The power wires are connected to the battery and the motor, and they carry the electrical power to the motor. The control wires are connected to the receiver and the microcontroller, and they carry the signals from the radio transmitter to the ESC.

The microcontroller is the brains of the ESC, it reads the signals from the control wires and uses that information to control the amount of power that the motor receives. It does this by switching the power on and off very quickly, a process called pulse width modulation (PWM). By varying the width of the pulses, the microcontroller can control the speed of the motor.

The ESC also has a built-in safety feature called low voltage cut-off (LVC), which helps to prevent damage to the battery. This feature will automatically cut off power to the motor when the battery voltage drops too low, protecting the battery from over discharge.

In summary, the RC ESC is a device that controls the speed of a brushless electric motor by regulating the amount of power it receives using the input of a radio transmitter, through a microcontroller that uses PWM, and also have a built-in safety feature to protect the battery. It is a crucial component in any RC vehicle and makes it possible for us to have fine control over the speed and performance of our RC cars and trucks.