Starter Activity

Enjoy ;)

Control Systems

AS ICT Asser Ayman

Objectives

• To know what a control system is

• Knowing the common variables controlled by a control system

• Be able to describe the applications that these uses can be put to.

What is a control system?

→ A “control system” is a device,

or set of devices that are used to

manage, command and direct the

behavior of other device

Examples of

control systems

• Air conditioning systems

• Central heating systems

• Refrigeration

• Medical applications: Intensive care

• Car Manufacture plants

• Process Control

Variablescontrolled by control systems

Temper a tu r e

P r e s su r e

Humid i t y

L ig h t

Moi s tu r e

And mor e X D

Hardware requirements: Input• N u m e r i c Ke y p a d

• P u s h b u t t o n s / s w i t ch e s

• Te m p e r a t u r e s e n s o r

• M o i s t u r e s e n s o r

• P r e s s u r e s e n s o r

• L i g h t s e n s o r

• C o n t a c t S w i t ch

Hardware requirements: Process

►ADC ( Analogue to digital converter )

→ Used to translate signals coming from devices such as sensors into signals that a computer can

read and process.

►DAC ( Digital to analogue converter )

→ Used to translate digital signal output of the computer to signals that other devices can read

and act upon.

►Timer

Hardware requirements: Output• Robo t

• Fans

• Hea t e r s

• Bo i l e r s

• Buzze r /a l a r m

• L ig h t s

• L ED d i sp l ay

Central heating systems

A “central heating system” provides warmth to the whole

interior of a building (or portion of a building) from

one point to multiple rooms. When combined with other

systems in order to control the building climate

Central heating systems

The boiler is controlled by a microprocessors that is

controlled using a touch screen. It heats the water in the water

cylinder which obviously stores heated water until it’s used.

When the radiators are turned on, the pump starts moving the

heated water from the water cylinder to the radiator through

pipes running usually inside the house’s walls (being outside

will give an ugly scene) using convection the atmosphere of

that part of the house starts changing its temperature.

Central heating systemHardware required for

› Bo i l e r

› Hot wa t e r c y l i nde r

› P ump

› Rad i a to r s

› Temper a tu r e s en so r s Used to heat water

To store heated water from boiler

Pumps the water across the pipes to radiators

Metal panels that are fixed to the wall in the

rooms that need heating

Monitors temperature continuously and sends

feedback to microprocessors

P.S>> this is going to look confusing ;) The arrows should give u a hint :P

Inputs Processes Outputs

Touch screen Sensors monitor temperature continuously LED display

Number pad or dialAnalogue data from temperature sensor

converted to digital by ADCRadiators

Temperature sensorTemperature compared to preset range/value

input by user

Signal sent to actuators to switch pump on & open valves if temp is too low

Signal sent to actuator to switch pump off/close valves if temp is OK

Closed Loop system

• Output directly affects the input

• No human intervention is

necessary

• Good for situations where control

is required 24/7, or in a

dangerous/difficult environment

This actually means that the system controls it

self.. It is not necessarily as good as you think

because these could’ve been jobs for

JOBLESS people.

Homework

χ Describe a central heating system in your own words

χ Mention the uses of a central heating system

Class dismissed ;)