Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 3rd Term
Week: 7
Age: 15 years
Duration: 45 minutes
Subject: Basic Electricity
Curriculum Theme: Basic Electricity
Previous Lesson: Power Supplies: Parts and Functions.
Topic: CONVERTERS
Subject Matter: Definition of converter, types of converters, basic examples of conversion processes in power electronics

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define what a converter is.
List and describe different types of converters.
State basic examples of conversion processes in power electronics.

Affective Domain:

Appreciate the importance of converters in various electrical systems.
Show interest in learning more about how electrical energy is transformed.

Psychomotor Domain:

Identify practical examples of converter devices in their environment.
Draw simple block diagrams representing different converter types.

Collaborate with peers to discuss the applications of different converters.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Senior Secondary Schools.
State Unified Scheme of Work for Basic Electricity SSS 1.
Basic Electricity for Senior Secondary Schools by P.N. Okoro.
Relevant charts and diagrams of converters.

Instructional Materials

The teacher will teach this lesson with the aid of:

Converter diagrams on charts or projector.
Sample converter devices (e.g., phone charger, power adapter, small inverter).
Whiteboard and markers.

Rationale for the Lesson

This lesson helps pupils understand how electrical energy is changed from one form to another. It explains the devices that make these changes possible, which are common in many electronic gadgets they use daily and are important for modern technology.

Prerequisite/Previous Knowledge

Pupils are expected to have a basic understanding of electricity, including concepts like voltage, current, Alternating Current (AC), and Direct Current (DC).

Lesson Content/Board Summary

CONVERTERS

Definition of a Converter

A converter is an electrical device that changes electrical energy from one form to another. It can modify voltage, current, or frequency, or convert AC to DC and vice versa.

Types of Converters

The following are common types of converters:

AC-DC Converter (Rectifier): This device changes Alternating Current (AC) into Direct Current (DC).
DC-AC Converter (Inverter): This device changes Direct Current (DC) into Alternating Current (AC).
DC-DC Converter (Chopper): This device changes a DC voltage level to another DC voltage level (either increasing or decreasing it).
AC-AC Converter (Cycloconverter/AC Voltage Controller): This device changes AC voltage or frequency to another AC voltage or frequency.

Basic Examples of Conversion Processes in Power Electronics

The following are basic examples of how converters are used in power electronics:

Rectification: Converting the AC mains supply to DC for charging mobile phone batteries or powering various DC electronic devices like laptops and radios.
Inversion: Converting DC from sources like car batteries or solar panels to AC to power household appliances such as fans, televisions, and lights.
DC Voltage Regulation: Using DC-DC converters to step down battery voltage for microcontrollers or to step up voltage for specific high-voltage applications.
AC Voltage Control: Adjusting AC voltage for applications like motor speed control in industrial machinery or for dimmer switches used in lighting systems.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to name some electronic devices they use daily. The teacher then asks what kind of power these devices use (AC or DC) and how they get it.
Pupils’ Activity: Pupils respond by naming devices and discussing their power sources.
Learning Point: Pupils connect their prior knowledge of electrical devices to the concept of power conversion, preparing them for the lesson on converters.

Step 2: Definition of a Converter

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines what a converter is, explaining its primary function of changing electrical energy from one form to another. The definition is written on the board.
Pupils’ Activity: Pupils listen attentively, take notes, and ask questions for clarification.
Learning Point: Pupils understand the fundamental definition and purpose of an electrical converter.

Step 3: Types of Converters

Time: 8 minutes
Teaching Skill: Elucidation/Categorization
Teacher’s Activity: The teacher introduces the different types of converters (AC-DC, DC-AC, DC-DC, AC-AC) using charts and simple block diagrams. Each type is briefly explained.
Pupils’ Activity: Pupils observe the diagrams, listen to the explanations, and take notes on the various converter types.
Learning Point: Pupils can identify and describe the main categories of electrical converters.

Step 4: Basic Examples of Conversion Processes

Time: 8 minutes
Teaching Skill: Illustration/Application
Teacher’s Activity: The teacher provides practical examples of conversion processes for each converter type, relating them to common electronic devices and systems. Examples are written on the board.
Pupils’ Activity: Pupils relate the examples to real-world scenarios and ask questions about specific applications.
Learning Point: Pupils understand the real-world applications of different converter types.

Step 5: Teacher Demonstration/Illustration

Time: 5 minutes
Teaching Skill: Demonstration/Visual Aid
Teacher’s Activity: The teacher uses actual sample converter devices (e.g., a phone charger for AC-DC, a small inverter for DC-AC) to show pupils what these devices look like and explain their function. Diagrams are also used to reinforce understanding.
Pupils’ Activity: Pupils observe the devices and diagrams, connecting the theoretical knowledge to physical objects. They may ask questions about the devices.
Learning Point: Pupils gain a visual and practical understanding of converters.

Step 6: Class Discussion/Q&A

Time: 5 minutes
Teaching Skill: Questioning/Engagement
Teacher’s Activity: The teacher facilitates a short class discussion, asking pupils to recall specific examples of converters they encounter daily and their functions. The teacher also addresses any lingering questions.
Pupils’ Activity: Pupils actively participate by sharing their observations and asking questions, clarifying their understanding.
Learning Point: Pupils consolidate their understanding through interactive engagement and peer learning.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define a converter.
Mention any three types of converters.
Give two examples of where an AC-DC converter is used.
Explain the function of a DC-AC converter.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of converters in modern electrical and electronic systems. The teacher then gives pupils a brief assignment to research more examples of converters.
Pupils’ Activity: Pupils listen to the summary and note down the assignment.
Learning Point: Pupils consolidate their learning and are encouraged to further explore the topic.

Lesson Keywords

Converter – An electrical device that changes electrical energy from one form to another.
Rectifier – An AC-DC converter that changes alternating current to direct current.
Inverter – A DC-AC converter that changes direct current to alternating current.
Chopper – A DC-DC converter that changes a DC voltage level to another DC voltage level.
Cycloconverter – An AC-AC converter that changes AC voltage or frequency to another AC voltage or frequency.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to research more complex converter applications (e.g., in electric vehicles). For pupils needing additional support, the teacher will provide simplified diagrams and allow more time for questions and one-on-one explanations.

Note for teachers using this lesson plan

Teachers should ensure to use clear and simple language, providing many practical examples that pupils can relate to their daily lives. Visual aids such as diagrams and actual converter devices are important for effective learning in this topic. Encourage pupils to ask questions and participate in discussions.