© Boardworks Ltd 2003 1 of 13 Control Devices Control For more detailed instructions, see the Getting Started presentation. This icon indicates the slide.

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Control Devices

Control

For more detailed instructions, see the Getting Started presentation.

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Computers are capable of controlling many other devices.

Who’s in control?

Another word for this is device control – one thing controlling another by sending it signals.

Peripheral devices (devices linked to your computer) such as your printer and speakers are controlled directly by your computer.

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Computers control devices all around the house.

Processors that are the same (or similar) to those found inside your home computer are used everywhere!

They may control time, power, electric motors and so on, in the following devices:

They may be doing work for you such as starting or finishing at a set time.

microwaveswashing machinestelevisionsvideo recorderselectronic games.

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Control systems are part of everyday life. They are all around us.

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Imagine you are being driven into a car park. Think about what is being controlled.

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Every system must have an input and an output.

How things work

Input usually has to do with the computer being told to do something from an external device, such as your fingers on a keyboard or your voice via a microphone.

Output usually has to do with the computer making a peripheral (outside) device do something, such as making a speaker produce sound or a printer print a document.

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Computers that are linked to sensors are very good at counting.

Count ‘em

Computers use tiny circuits called logic circuits in the processor to add things up every time the sensor sends them a signal.In the car park example there was a counter counting the cars going in and going out of the car park.

This is very important to ensure that there are not more cars than spaces in the car park.

Counters are used everywhere! For example:

counting the number of cars that use a roadcounting tin cans as they pass along a production linecounting people entering a sports stadium.

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The terms cause and effect are used a lot in computer control.

For every cause an effect

An example of cause and effect would be if a burglar broke a window (the cause) the burglar alarm would begin sounding (the effect).

This is because a sensor has sent a message to the computer which controls the alarm. The sensor might be a light beam across the window which, when broken, tells the computer to sound the alarm.

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Summary

What can I remember?

Computers are capable of controlling many devices.

Every system has an input and an output.

Computers use tiny circuits called logic circuits in the processor to add things up every time the sensor sends them a signal.

For every cause there is usually an effect.