Component review


UK Power Networks - Circuit Components

In my previous blog, I detailed how I reviewed my notes in order to ease the process of building my project. This is a continuation with a review of the basic components of a circuit.

Key concept

  • Understand what a resistor, LED, capacitor and transistor do


Resistor Stock Photo - Download Image Now - iStock

Resistor: A resistor is a passive electrical component that implements electrical resistance in a circuit. In audio they are used to adjust signal levels. There are many different types of resistors with different values and they determine how much resistance there is within a circuit.

Different resistors can be identified through the colour of their bands.

Resistor Colour Code
Resistor colour band chart

Transistors: A semiconductor device used to amplify or switch electrical signals and electrical power. In simple terms it can turn a current on or off. The two most common transistors are BJT and MOSFET.
Bipolar Junction Transistor: Has 3 legs and includes 3 parts. Base, collector and emitter. If you turn it on the current will be able to flow from the collector to the emitter. If its turned off then it does not work.

Application of bipolar junction transistor (BJT) - Polytechnic Hub
BJT Transistor

MOSFET: It has 3 pins. Gate, source and drain. One important difference between the two is that in the BJT transistor, the current from base to emitter decides how much current can flow from collector to emitter. In MOSFET transistor, the voltage between gate and source decides how much current can flow from drain to source.

Nettigo: N-channel MOSFET transistor, 60V, 16A
MOSFET Transistor

Why a transistor: A great advantage the transistor provides is that you can use a small voltage/current to control a much larger voltage/current.
Furthermore in audio a transistor allows for the existence of an amplifier on and off state.

Capacitor: Much like the name states, a capacitor stores electrical energy in a circuit. It is a passive electrical component with two terminals allowing for connections to both the positive and negative side. Capacitor work like filters. In audio it is quite literal that they are used in LPF/HPF. A clock is an example of an everyday object that uses a transistor.

How Does A Capacitor Work? - Build Electronic Circuits

LED: An LED or light emitting diode is a semiconductor light source that emits light when current flows through it. Its function is to light up if a current flows through it to show that a current is flowing. It is very common and can be seen in many everyday things such as a laptop.

What Is An LED (Light-Emitting Diode)? - Build Electronic Circuits

Practice makes perfect

Now that the basic components have been reviewed, the best way to understand them is to get a hands on experience with them. For my case, before I begin building my circuit I will build basic circuits with the help of circuit diagrams in order to make the whole project easier to understand.

Circuit Diagram | MyDraw
Circuit Diagram