WDifferences between DC Motor 12 V and Servo Motor

A motor is a machine that produces a motion whenever powered on. A current running through a coil of wire generates an electromagnetic field along the centre of the coil causing movement of the shaft of the motor.

Function:Drive power is supplied to the DC motor 12V through a two wire connection. Like a light bulb, the DC motor has no electronics of its own and requires a heavy drive current for it to run. When switched on it rotates very fast (about 5000 RPM) freely through 360 degrees.

dc motor 12v

Control:The speed of the DC motor 12V is controlled using Pulse Width Modulation (PWM). The motor’s power level is controlled by switching power on and off. The duty cycle (on-off time percentage) decides the power of operation.

Servo Motor:A servomotor consists of a normal DC motor 12V, a position sensor, a reduction gear mechanism and a motor controller device. When powered on, the motor controller gives a signal to the servo to move to a particular position. A position sensor senses the servo position and gives a feedback signal that determines the magnitude and direction of DC motor movement always.

Function:The servo has a constant power source through a three wire connection for power, ground, and control each. The drive electronics of the servo draws current from the power lead and supplies drive to the motor. The servo DC motor does not rotate freely but turns only about 200 degrees either side.

Control:Although the control signal is Pulse Width Modulated (PWM), the duration of the positive-going pulse determines the position of the servo shaft. The servo control pulse which gets repeated every 20 milliseconds decides the turn magnitude and direction. A longer pulse makes servo turn to clockwise and a shorter pulse to counter-clockwise from the centre position.