Circuits and Circuit Design

Basic Concepts of Circuits

An electrical circuit is a path in which electrons from a voltage or current source flow.
The components in a circuit are joined by conducting wires and are powered by a power source such as a battery or mains electricity.
The flow of current is from the positive to the negative terminal in a circuit.
A closed circuit allows electricity to flow, while an open circuit stops the flow of electricity.
In a series circuit, components are connected end-to-end, so there is only one path for the current.
In a parallel circuit, components are connected across each other, providing multiple paths for the current.

Circuit design involves planning the arrangement of electronic components in a circuit and creating schematic diagrams.
When designing a circuit, consider the layout of components, the type of components needed, and the connections between them.
Make use of standard circuit symbols to represent different components in your schematic diagrams.
Be mindful of the current, voltage, and resistance in your circuit, as these will affect its operation.

Analog circuit design involves designing circuits for continuous, varying signals such as in radio receivers, audio amplifiers, and power supply units.
Digital circuit design involves designing circuits for discrete signals, most commonly binary signals used in processors and memory chips.
Mixed-signal circuit design combines both analog and digital components, often used in devices such as smartphones and digital cameras.

Use tools like breadboards and soldering equipment to prototype and assemble circuits.
Oscilloscopes and multimeters are essential tools for testing and troubleshooting circuits.
Circuit analysis, the process of finding the voltages across and the current through every component in the network, is crucial for a functioning circuit.
Modern circuit design often involves computer-aided design (CAD) software which can help simulate and analyse circuits before they are built.

Prototyping is the process of creating a preliminary model or sample of the circuit to test its functionality.
It’s important to test your circuit incrementally, checking each component and connection before moving on to the next.
Use fault-finding techniques such as checking for short and open circuits if your prototype does not work as expected.
Once your prototype works as needed, you can produce a final circuit. This may involve transferring your breadboard design to a printed circuit board (PCB).