Servomotor is a position control rotary actuator. (You can achieve 180 degrees by adjusting the rotation angle of the motor in the code)It mainly consists of housing, circuit board, core-less motor, gear and position sensor. Included with your servo motor you will find a variety of white motor mounts that connect to the shaft of your servo. You may choose to attach any mount you wish for the circuit. It will serve as a visual aid, making it easier to see the servo spin.

Working principle:

The receiver or MCU outputs a signal to the servomotor. The motor has a built-in reference circuit that gives out reference signal, cycle of 20ms and width of 1.5ms. The motor compares the acquired DC bias voltage to the voltage of the potentiometer and outputs a voltage difference. The IC on the circuit board will decide the rotate direction accordingly and drive the core-less motor. The gear then pass the force to the shaft. The sensor will determine if it has reached the commanded position according to the feedback signal. Servo motors are used in control systems that requires to have and maintain different angles. When the motor speed is definite, the gear will cause the potentiometer to rotate. When the voltage difference reduces to zero, the motor stops. Normally, the rotation angle range is among 0-180 degrees.

Servo motor comes with many specifications. But all of them have three connection wires, distinguished by brown, red, orange colors (different brand may have different color). Brown one is for GND, red one for power positive, orange one for signal line.The rotation angle of servo motor is controlled by regulating the duty cycle of PWM (Pulse-Width Modulation) signal. The standard cycle of PWM signal is 20ms (50Hz).

Theoretically, the width is distributed between 1ms-2ms, but in fact, it’s between 0.5ms-2.5ms. The width corresponds the rotation angle from 0° to 180°.
But note that for different brand motor, the same signal may have different rotation angle.

Parameters

• Operating voltage: DC 4.8V〜6V

• Angle range: about 180°(in 500→2500μsec)

• Pulsewidth range: 500→2500μsec

• No-load speed: 0.12±0.01 sec/60（DC 4.8V）; 0.1±0.01 sec/60（DC 6V）

• No-load current: 200±20mA（DC 4.8V）; 220±20mA（DC 6V）

• Stop torque: 1.3±0.01kg/cm（DC 4.8V）; 1.5±0.1kg/cm（DC 6V）

• Stop current: ≦850mA（DC 4.8V）; ≦1000mA（DC 6V）

• Standby current: 3±1mA（DC 4.8V）; 4±1mA（DC 6V）

• Operation temperature: -10℃〜50℃

• Save temperature: -20℃〜60℃

• Motor wire length: 250 ± 5 mm

• Dimensions: 22.9mm*12.2mm*30m

• Weight: 9± 1 g (without servo mounts)

Tutorial for your reference //fs.keyestudio.com/KS0194