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Computer Science IGCSEPDF 69
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Automatic doors and elevators
6.2 Components of an Automated System
Automated systems operate in three stages:
1. Input Devices (Sensors)
Function:
Sensors collect data from the environment and convert physical quantities (e.g. temperature,
pressure, light) into electrical signals.
Common Sensors:
Sensor
Temperature sensor
Purpose
Measures heat
Example
Thermostat, oven
Light sensor (LDR)
Measures brightness
Streetlights
Pressure sensor
Detects pressure/force
Car tyres, elevators
Infrared sensor
Detects movement
Sound sensor (microphone)
Detects sound
Automatic doors
Voice-activated systems
Moisture/humidity sensor
Measures moisture
Greenhouses