2 - Circuits Diagrams and Circuit Boards


To make a lamp light up, we need a power source. If we would like to turn it on and off manually, we might incorporate a suitable switch. These different devices are known as components.

When connected together, these components form a circuit and the details of this can be shown on a circuit diagram.

Circuit diagrams use symbols to represent the different components. Straight lines represent the wires connecting the components together.

In the following circuit diagram, the switch has been left out and the two lamps connected directly to a cell by wires.

Example Circuit Diagram

Many different electrical or electronic components are used in the circuits found inside electronic products we use. These circuits are usually built on circuit boards. To take the place of the circuit's interconnecting wires, these boards have specially arranged conducting copper tracks to allow the components to be connected together by soldering. This allows manufacturers to make smaller, more reliable products.

 

Example: FastTrack Circuit Board

 

The copper tracks are usually tinned with solder to make them easier to solder to. Sometimes it is necessary for them to be plated in gold, to make them better electrical conductors.

Materials that do not allow electrical current to flow are called insulators. The green coating on this circuit board is "solder resist" and does not conduct. It therefore helps to prevent shortcircuits occuring between the tracks when the components are being soldered to the round pads.