3. 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.
4. 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
5. Examples of
control systems
• Air conditioning systems
• Central heating systems
• Refrigeration
• Medical applications: Intensive care
• Car Manufacture plants
• Process Control
7. Hardware requirements: Input
• Numeric Keypad
• Push buttons/switches
• Te m p e r a t u r e s e n s o r
• Moisture sensor
• Pressure sensor
• Light sensor
• Contact Switch
8. 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
10. 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
11. 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.
12. P.S>> this is going to look confusing ;) The arrows should give u a hint :P
To store heated water from boiler
› Boiler
Monitors temperature continuously and sends
› Hot water cylinder feedback to microprocessors
› Pump Metal panels that are fixed to the wall in the
rooms that need heating
› Radiators Pumps the water across the pipes to radiators
› Te m p e r a t u r e s e n s o r s Used to heat water
Central heating system
Hardware required for
13. Inputs Processes Outputs
Touch screen Sensors monitor temperature continuously LED display
Analogue data from temperature sensor Radiators
Number pad or dial converted to digital by ADC
Temperature compared to preset range/value
Temperature sensor 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
14. 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.
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
15. Homework
χ Describe a central heating system in your own words
χ Mention the uses of a central heating system