Basic Electrical Training Card
Chapter 1: Introduction

Lesson 2: Exploring the Components of a Simple Circuit

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Here’s the path the current takes:

  1. B+ Test Point – This is the positive power source. It represents the battery’s positive terminal.

  2. Switch – The sliding switch controls whether current can flow. When it’s turned on (to the right), the circuit is complete, and power can move through the rest of the components.

  3. Resistor – The resistor limits the amount of current flowing through the circuit. This protects the LED from too much current and demonstrates how resistance affects voltage drop.

  4. LED (Light Emitting Diode) – The LED lights up when current flows through it in the correct direction. This shows that LEDs only conduct one way and helps visualize current flow.

  5. Ground (GND) – The ground point completes the circuit, returning current to the negative side of the power source — just like the chassis ground in a vehicle.

You’ll notice test points placed between each component.
These are used to take voltage measurements with a multimeter so you can see how voltage changes as it moves through the circuit.