Lesson Notes By Weeks and Term v4 - SHS 3
ELECTRICAL SYSTEMS DESIGN
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
ELECTRICAL SYSTEMS DESIGN
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Applied Technology
Class: SHS 3
Term: 2nd Term
Week: 8
Grade code: 2.4.1.LI.4
Strand code: 4
Sub-strand code: 1
Content standard code: 2.4.1.CS.1
Indicator code: 2.4.1.LI.4
Theme: ELECTRICAL AND ELECTRONIC TECHNOLOGY
Subtheme: ELECTRICAL SYSTEMS DESIGN
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
Welcome, students. Today, we are exploring a very important machine: the DC (Direct Current) generator. Think about times when the main power from the national grid ("light off" or "dumsor") goes out. Many businesses, hospitals, and even homes use generators to provide backup power. While many are AC generators, DC generators are specialists with crucial roles, especially in charging batteries, welding, and in vehicles. Understanding how these machines convert mechanical energy (from a spinning engine) into useful DC electrical energy is a fundamental skill in electrical technology.
A. Principle of Operation: How a DC Generator Works
The operation of a DC generator is based on a fundamental principle in physics discovered by Michael Faraday.
Faraday's Law of Electromagnetic Induction: This law states that whenever a conductor cuts through magnetic lines of force (or magnetic flux), an electromotive force (EMF), or voltage, is induced in that conductor.
For this to happen, three things are required: A magnetic field (produced by magnets or electromagnets). A conductor (usually a coil of copper wire). Relative motion between the conductor and the magnetic field (one must move relative to the other).