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Computers can take readings from sensors automatically. This can be helpful in control systems where responses need to be triggered due to changes in environmental conditions.

Example of a Street Lamp Control System

A street lamp turns itself on an off automatically each morning and evening. This flowchart describes the three components of the control system:


This flowchart describes how the control program will decide what to do with the lamp:


Notice that there is no stop symbol in this flowchart. The control program would carry on forever in a repeating cycle to keep checking if the light levels had changed. This is called iteration and is usually entered into the computer using a repeat command.

Advantages of using Control Systems

Control systems like this are useful because they can:
  • respond more quickly than humans to changes in environmental conditions;
  • work continuously without making mistakes – they are very accurate and won’t get tired.
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