Topic 1 System Synthesis

Topic 1 System Synthesis

Systems Approach

Electronic systems consist of:

· An input device to sense changes, e.g. a light detector

· A processor that responds to the change

· An output device that enables the system to do something useful.

· There may be feedback to control the response of the circuit.

We can represent this very basic idea with a block diagram:

Now try Question 1, Question 2, and Question 3.

A Circuit diagram tells us:

· How the components are laid out and wired up.

· Engineers use circuit diagrams to assemble the circuit.

· It uses standard symbols with which you need to be familiar.

· The lines represent the copper tracks on the circuit board. Where the lines are connected there is a black dot, to represent a blob of solder.

Click on the picture to find out more from the excellent Doctronics website:

Now try Question 4

For more info, go to http://www.kpsec.freeuk.com/index.htm, an excellent site from Kelsey Park School

Block diagram.

This is a block diagram for a domestic burglar alarm.

With a block diagram we can split a complex system into a number of smaller sub-systems.

Often a complex circuit is built on several boards with each sub-system or module on a separate board. This has several advantages:

The circuit boards can be built and tested separately.

If the circuit goes wrong, the defective module can be easily removed without having to replace everything else.

Modifications can be made more easily.

Here is a simple block diagram of a train sound system that might be used for a model railway.

The wiring diagram shows the power supplies to the components of a circuit.

It shows:

The way the wires are connected between the components.

The way the wires may be in looms

The colour of the wires

There are some points that we can note for all electronic circuits:

Most electronic circuits use low voltage dc.

Most electronic circuits cannot give out a lot of power.

There are ways of interfacing low voltage circuits with high power outputs.

Often power supplies are omitted from circuits for clarity, but it is essential that they be put in when we build the circuit. The pin-out diagram shows the power supply as well as all the other connections.

Now try the topic quiz.

Presentation

System Synthesis

Useful Websites

http://home.howstuffworks.com/burglar-alarm1.htm

http://www.doctronics.co.uk/biscuit.htm

http://electronics.howstuffworks.com/amplifier.htm

Summary

Electronic systems consist of input, process, and output;
There may be feedback;
Circuit diagrams show the layout and connections of components;
Engineers use circuit diagrams to assemble the circuit.
Block diagrams show how a complex circuit can be broken down to subsystems.
Subsystems may be on separate boards that can be exchanged;
Wiring diagrams show how the circuit systems can be wired together.

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