3.1 DC Motor Fundamentals3.1.1 Torque, Current, and KT3.1.2 Rotational Speed, Voltage, and KV3.1.3 The KT-KV Tradeoff3.1.4 Switching Circuitry3.1.5 Pulse Width Modulation (PWM)3.2 Brushed Motors3.2.1 Mechanical Commutation3.2.2 Types of Brushed Motors3.2.3 Advantages and Disadvantages3.2.4 Control Circuitry3.3 Brushless Motors3.3.1 BLDC Structure3.3.2 Inrunner and Outrunner Motors3.3.3 Controlling BLDCs3.4 Electronic Speed Control (ESC) Systems3.4.1 Battery Eliminator Circuit (BEC)3.4.2 Programmability3.5 Batteries3.6 Summary