Output Devices : Control Devices

Output Devices : Control Devices

Computers can also be used to control other devices such as motors and lights which can be switched on and off. These devices are activated by electrical signals sent to them by a computer.

There are lots of different devices available. Examples of common devices include :

Device	Action Produced	Application
Bulb	Lights up an area.	Lighting up a garden when a person walks into the area.
Motor	Rotation of a shaft.	Moving a buggy.
Buzzer	Makes a short beep noise.	Warning a pilot of a dangerous situation.
Pump	Moves gasses or liquids from one place to another.	Keeping a fish tank supplied with oxygen.
Heater	Produces heat.	Keeping a house warm in a central heating system.
LCD Display	Displays short sequences of numbers or letters.	Information readout on a till.

The action of many devices will depend upon how high or low the analogue voltage that is sent to the device is. For example :

A motor will rotate more quickly if it is supplied with a high voltage than if it is supplied with a low voltage.
A bulb will glow more brightly if it is supplied with a high voltage than if it is supplied with a low voltage.

Devices like these are used by computerised control systems.

Computer Assisted Manufacturing (CAM) systems can control devices such as CNC lathes and robots and use these to make items.

GCSE ICT Companion 04 - (C) P Meakin 2004