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13. Output Devices

For this week, I have learnt on [Output Devices]

Output Devices

Output devices are the electronic parts of the computer. A computer’s output devices are those part of computer hardware equipment that converts the information into readable form. It can be text, graphics, audio, or video.

For this week, I have worked on:

Group Assignment

We have measured the power consumption of an output device. If you have interest, you can CLICK HERE to know more about the details.

Individual Assignment:

Servo Motor Servo motor, which is chosen for my assignment in this week, is the DC motor that allows for precise control of the angular position. In the DC motors, their speed is slowly lowered by the gears.

Operating Power of DC and AC Servos

DC Servos are used for providing fast torque response and are also known as a permanent magnet DC motor or separately excited DC motor. The reason behind providing fast torque response is because of the torque and flus are decoupled. Thus, a small variation in the armature voltage or current can produce a notable shift in the position or speed of the shaft. DC servos are most used servo motors among all the types.

There are two types of AC servo motors. The one is 2 phase and the second is 3 phase. Mainly two-phase squirrel cage servo motor is used for low power applications. Three-phase squirrel cage servo is used for high power systems.

Construction of Servos

The Servo motor is DC motor which has 5 following parts:-

  1. Stator Winding
    This type of winding wound on the stationary part of the motor. It is also known as field winding of the motor.

  2. Rotor Winding
    This type of winding wound on the rotating part of the motor. It is also known as an armature winding of the motor.

  3. Bearing
    These are of two types,i.e, font bearing and back bearing which are used for the movement of the shaft.

  4. Shaft
    The armature winding is coupled on the iron rod is known as the shaft of the motor.

  5. Encoder It has the approximate sensor which determines the rotational speed of motor and revolution per minute of the motor.

Revolutions of Servos

The servo motors usually have a revolution cut off from 90° to 180°. A few servo motors also have a revolution cutoff of 360° or more. But servo motors do not rotate constantly. Their rotation is limited between the fixed angles.

Application in industry
servo motors are used in machine tools, packaging, factory automation, material handling, printing converting, assembly lines, and many other demanding applications robotics, CNC machinery, or automated manufacturing.

ES08MAII Servo Motor
For this week assignment, I have chosen ES08MAII Servo motor and may apply to my final project.

Each motor has three inputs: VCC, ground, and a periodic square wave signal. The pulse width of the square wave determines the speed and direction of the servo motors.

The following draft was the System Integration Diagram (SID). This diagram showed each integration of connection between different components in the system.

For this time, the signal pin of servo connected to the pin PA0 of the ATTiny44.

ES08MAII Servo Motor and ATTiny44 were used.

Before connection between them, signal should be found from the pinout diagram for ATTiny44. PA0 was the signal pin we should used this time.

The following video can show the servo worked with ATTiny44 properly.

CLICK HEREto know more about about Electonics Production of this PCB board.

CLICK HERE to know more about electronics design this PCB Board.

In my final project, I have planned to have a light sensor to control the solar panel for chasing sunlight

Therefore, I need to change the direction to allow the solar panel to move forward, backward, and turn left and right. If the pulse width is under a certain time frame, the motor will drive in a clockwise direction. If the pulse width exceeds that time frame, the motor will drive in a counterclockwise direction. The middle time frame can be adjusted through a built-in potentiometer inside the motor.

File Download

***servo_test.ino


Last update: July 5, 2021