# 2.1: Basic Electrical Circuits

• • Camosun College
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Describe basic circuit concepts

You must understand how basic circuits function to properly diagnose and repair electrical problems. Now that you understand a simple circuit and how the basic components are connected, you can assemble more complex circuits and observe their characteristics.

Basic electrical circuits

A circuit must provide a complete path for current flow from the power source. The current must flow through a control device into an electrical load and back to the power source through a wire or through a vehicle chassis.

In equipment, wire is normally used only on the insulated side of the circuit, since the return circuit is the chassis. Some components may require a ground wire from the component to the frame This type of circuit is called the single wire system (Figure 1). Figure $$\PageIndex{1}$$: (CC BY-NC-SA; BC Industry Training Authority)
1. Single wire circuit Figure $$\PageIndex{1}$$: (CC BY-NC-SA; BC Industry Training Authority)
2. Two wire circuit

There are three types of basic electrical circuits:

• series circuits
• parallel circuits
• series-parallel (combination) circuits