Electrical Components and Wiring

Chapter 57 Electrical Components and Wiring Repair WyoTech

Lesson Objectives

  • Explain the operation of switches and circuit protection devices

  • Describe the operation of relays and solenoids

  • Describe common types of resistors

  • Describe basic operation of motors and transformers

  • Describe types and components of wiring harnesses

  • Replace wire terminals and perform solder repairs

  • Explain wiring diagrams and trace circuits

Operation of Switches and Circuit Protection Devices

  • Switch Functionality

    • Turns current on/off in the circuit

    • Off: Opens circuit, stopping current flow

    • On: Closes circuit, allowing current flow

  • Circuit Protection Devices

    • Automatically or manually open circuit when current is too high

    • Types include fuses, circuit breakers, fusible links, and thermistor devices

Types of Switches

  • Basic Switch Types

    • Toggle switches

    • Push-button switches

    • Specialty switches (e.g., turn signals, wipers)

  • Complex Switches

    • Many terminals/contact multiple circuits

    • Includes circuit and schematic diagrams

Circuit Protection Devices

  • Fuses and Circuit Breakers

    • Open circuits during high current flow

    • Blade Fuses: Common types with various amp ratings

    • Fusible Links: Melt at specific currents, placed near batteries

    • Circuit Breakers: Can reset themselves or be manually reset

Relays and Solenoids

  • Relay Operation

    • Controlled by smaller current, switches larger currents

    • Consists of electromagnet and switch contacts

  • Solid-State Relay

    • No moving parts, uses transistorized circuitry

  • Solenoid

    • Converts electric energy into mechanical linear movement

Resistors

  • Types of Resistors

    • Fixed Resistors: Contain colored stripes for value indication

    • Variable Resistors: Include rheostats and potentiometers

    • Thermistors: Resistance changes based on temperature

Motors and Transformers

  • Electric Motors

    • Comprise a field (magnets) and an armature (coil)

  • Transformers

    • Change output voltage/amperage from input

Wiring Harnesses

  • Components

    • Copper wiring is dominant for power/signals

    • Includes multi-stranded wire, ribbon cable, and drain lines

  • Terminals and Connectors

    • Include push-on, eye ring, and solderless terminals

    • Provide low-resistance terminations and facilitate serviceability

Wiring Diagrams

  • Diagram Types

    • Pictorial, Block, and Schematic diagrams

  • Purpose

    • Diagnose electrical circuit faults

Repair and Installation Techniques

  • Replacing Wire Terminals and Soldering

    • Inspect terminals for corrosion and damage

    • Use soldering techniques for strong electrical connections

    • Emphasize the importance of proper insulation and sealing (e.g., heat shrink tubing)

Summary Questions Overview

  • Identify key concepts regarding switches, fuses, relays, motors, and wiring harnesses to reinforce learning.


Chapter 57 Electrical Components and Wiring Repair WyoTech

Lesson Objectives

  • Explain the operation of switches and circuit protection devices in various applications.

  • Describe the operation principles and common uses of relays and solenoids in automotive and electrical systems.

  • Identify and describe common types of resistors, including applications and significance in circuit functionality.

  • Elucidate the basic operation of electric motors and transformers, highlighting their roles in energy conversion and mechanical work.

  • Describe the different types and components of wiring harnesses, including their construction and applications in vehicle systems.

  • Execute the replacement of wire terminals and perform solder repairs to ensure reliable electrical connections and longevity in repair work.

  • Explain how to read and interpret wiring diagrams and trace circuits for troubleshooting and repair.

Operation of Switches and Circuit Protection Devices

Switch Functionality

  • Purpose: Switches are essential components in electrical circuits that control the flow of current.

  • On State: When a switch is engaged to the 'On' position, it closes the circuit, thus allowing electrical current to flow through the system, powering up devices and components connected to the circuit.

  • Off State: Engaging the switch to 'Off' opens the circuit, effectively stopping the flow of electricity and preventing power from reaching connected devices.

Circuit Protection Devices

  • These devices are crucial for protecting electrical circuits from overload conditions.

  • Types: Circuit protection mechanisms automatically or manually interrupt the circuit when excessive current flows through, thereby preventing damage to wiring and components.

    • Fuses: These are designed to melt and disconnect the circuit at a specific current level. They must be replaced after an operation.

    • Circuit Breakers: These can trip automatically or be reset manually and are reusable.

    • Fusible Links: Positioned near batteries, they are designed to melt under excessive current to protect primary wiring from damage.

    • Thermistors: These resistive devices change resistance based on temperature, providing self-regulation in circuits.

Types of Switches

Basic Switch Types

  • Toggle Switches: Commonly used for general applications, they can be switched on and off through a physical lever or knob.

  • Push-button Switches: Often used in devices requiring momentary or continuous operation; simple and intuitive.

  • Specialty Switches: Include specific functions like turn signals and wiper controls in automotive applications.

Complex Switches

  • These have multiple terminals and can control multiple circuits or devices simultaneously.

  • Often depicted in circuit and schematic diagrams to show intricate operations and connections.

Relays and Solenoids

Relay Operation

  • Relays serve to control a high-power circuit with a much lower power signal.

  • Components: They consist of an electromagnet that, when energized, opens or closes switch contacts to control high currents.

  • Solid-State Relays: These variants use semiconductor technology without moving parts to switch power in a reliable and efficient manner.

Solenoid

  • A solenoid is a coil of wire that produces a magnetic field when electrical current passes through it, converting electrical energy into linear mechanical movement, often utilized in locking mechanisms and actuators.

Resistors

Types of Resistors

  • Fixed Resistors: Their resistance value is constant and indicated by colored stripes.

  • Variable Resistors: Include types like rheostats and potentiometers, which allow the user to adjust resistance levels manually.

  • Thermistors: Components whose resistance is temperature-dependent, utilized in temperature sensing and control applications.

Motors and Transformers

Electric Motors

  • Composed of a stationary magnetic field (field) and a rotating armature (coil) that converts electrical energy into mechanical motion.

  • Used in a variety of applications from automotive to household appliances.

Transformers

  • Devices that manage AC voltage levels by stepping voltage up or down while altering amperage, essential in power distribution and electronics.

Wiring Harnesses

Components

  • The predominant material for wiring harnesses is copper, valued for its electrical conductivity.

  • Harnesses may incorporate multi-stranded wire, ribbon cable for compact installations, and drain lines to manage moisture.

Terminals and Connectors

  • Types include push-on, eye ring, and solderless terminals, which provide secure, low-resistance connections and assist in simplifying service and repairs.

Wiring Diagrams

Diagram Types

  • Pictorial Diagrams: Visually represent components and their connections.

  • Block Diagrams: Simplify complex systems into functional blocks to illustrate connections and functions.

  • Schematic Diagrams: Detailed illustrations of electrical connections and devices used in circuits.

Purpose

  • Wiring diagrams are instrumental in diagnosing electrical circuit faults, guiding repairs, and installation methodologies.

Repair and Installation Techniques

Replacing Wire Terminals and Soldering

  • Inspect terminals for signs of corrosion and damage to ensure reliability of connections.

  • Utilize proper soldering techniques to guarantee strong electrical connections, emphasizing the role of insulation and sealing measures such as heat shrink tubing to protect the integrity of repairs.

Summary Questions Overview

  • Review and identify key concepts regarding switches, fuses, relays, motors, and wiring harnesses to reinforce learning and comprehension of essential electrical fundamentals.