Lesson Notes By Weeks and Term v4 - SHS 2

Lesson Video

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Performance objectives

• Define an inductor and its function.
• Identify different types of inductors.
• Explain the principle of inductance.
• Calculate the inductance of a coil.
• Design a simple circuit using an inductor.

Lesson summary

This lesson introduces learners to the inductor, a fundamental component in electronics. Alongside resistors and capacitors, inductors form the trio of basic passive electronic components. We see their effects everywhere, from the charging brick of our mobile phones to the large transformers used by the Electricity Company of Ghana (ECG) and the tuning circuits in our radios that allow us to listen to stations like Peace FM or Joy FM. Understanding how inductors work is crucial for anyone aspiring to repair, design, or innovate in the field of electronics. This lesson will focus on defining what an inductor is, describing its types, and explaining its role as a passive component.

Lesson notes

A. What is an Inductor?

An inductor, sometimes called a coil or choke, is a passive electronic component that stores energy in a magnetic field when electric current flows through it. Analogy: Think of an inductor like a heavy water wheel in a stream. When you first open the gate for water (current) to flow, the wheel resists turning because of its weight (inertia). It takes time for it to get up to speed. Once it's spinning, it has momentum. If you suddenly close the gate, the wheel will try to keep spinning and push the water forward for a moment. In Electronics: An inductor does the same thing with electric current. It resists any *change* in the current flowing through it. When current tries to increase, the inductor pushes back. When current tries to decrease, the inductor tries to keep it flowing. This property of resisting a change in current is called inductance. The standard unit of inductance is the Henry (H), named after Joseph Henry. In practice, we often use smaller units like the millihenry (mH, 10⁻³ H) and the microhenry (µH, 10⁻⁶ H). B. Why is an Inductor a "Passive" Component?

Electronic components are divided into two main categories: active and passive. Passive Components: These are components that do not require an external power source to operate and cannot amplify a signal or introduce energy into a circuit. They only consume, store, or dissipate energy. The three main passive components are Resistors (R), Capacitors (C), and Inductors (L). An inductor simply stores energy in its magnetic field and then releases it; it cannot generate power. Active Components: These components can control the flow of electricity and often require an external power source to function. They can amplify a signal (make it stronger). Examples include transistors, operational amplifiers (op-amps), and integrated circuits (ICs).

Therefore, an inductor is passive because it does not have gain or directionality and cannot amplify power. C. Basic Construction of an Inductor

Evaluation guide

• Creativity and innovation : Ability to use new
• ideas to design and create new designs with
• electronic components.
• relate to other learners when group assignment