1. Control
Control Devices

2. Who’s in control?
Computers are capable of controlling many other devices.
Peripheral devices (devices linked to your computer) such as your printer and speakers are controlled directly by your computer.
Another word for this is device control – one thing
controlling another by sending it signals.

3. 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:
microwaves
washing machines
televisions
video recorders
electronic games.
They may be doing work for you such as starting or finishing at a set time.

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

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

6. Put these actions into the correct order:

7. How things work Every system must have an input and an output.
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.

9. Count ‘em
Computers that are linked to sensors are very good at counting.
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 road
counting tin cans as they pass along a production line
counting people entering a sports stadium.

10. For every cause, there is an effect
The terms cause and effect are used a lot in computer control.
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.

13. How Can Computers Control Things?
A computer control system, like any system, is made up of three parts...
Input devices called sensors feed data into the computer
The computer then processes the input data (by following a set of instructions)
As a result of the processing, the computer can turn on or off output devices called actuators.

14. The best way to understand how a computer can control things is to think about how a person controls something... For example, how does a human control a car when he/she is driving? The person looks ahead at the road to see what is approaching, thinks about what he/she has seen, then acts upon it (turns the steering wheel and/or presses the pedals).

15. In other words the person reacts to what is happening in the world around them. Computer-controlled systems work in a similar way – the system detects what is happening in the world around it, processes this information, and then acts upon what it has detected.

16. Summary The End 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.
What can I remember?
The End