Sensors and Actuators (Junior Cert Applied Technology): Revision Notes

Sensors and Actuators

Introduction

• Sensors and actuators are vital parts of control systems. They provide data input and do the actions needed to make a system work. They help automate tasks and improve efficiency.

Definitions

• Sensor: Detects changes in the surroundings and sends this information to the control system.
• Actuator: Turns input signals into actions in a control system.

Types of Sensors

• Infrared Sensors

  • Detect objects and motion using infrared light.
  • They can turn lights on by sensing movement and improve security systems.

• Temperature Sensors

  infoNote

  Temperature sensors are essential for maintaining comfortable environments in residential and commercial buildings.

  • Measure heat changes and change them into signals.
  • Manage HVAC systems to keep temperatures steady.

• Capacitance Sensors

  • Measure changes in capacitance to find touch or closeness.
  • Used in smartphones for touch controls.

Actuators

• Types of Actuators
  • Electric Actuators: Change electrical energy into movement.
    • Provide precise actions for tasks needing care.
  • Hydraulic Actuators: Use liquid power to do work.
    • Deliver strong movements in heavy machines.
  • Pneumatic Actuators: Use air pressure for movement.
    • Useful for fast actions in machines.

Examples of Devices

• Desk Fan
  • Uses a temperature sensor to activate automatically.
  • Uses actuators to direct airflow effectively.

Importance of Feedback

• Good feedback from sensors helps keep systems accurate.
• Feedback loops help systems adjust and work well.

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