Unit2-L2-T.English

University Overview

  • Institution: University of Science and Technology Houari Boumediene

  • Faculty: Faculty of Electrical Engineering

  • Department: Department of Electronics

  • Course: Technical English For Electronics

  • Prepared by: Dr. Boutana Nassiha

  • Target Group: Students L2

Unit 2: Electric Circuits

Definition of Electric Circuit

  • Electric Circuit/Network: A pathway for electric current flow.

  • Simple Circuit Components:

    • Power source (battery or generator)

    • Two conducting wires connected to the terminals o Load: Device (e.g., light bulb) that allows electricity to flow through.

  • Closed Circuit: All parts properly connected; current flows and device operates.

  • Open Circuit: Wires disconnected; current does not flow.

  • Switch: Device that opens/closes the circuit.

Functions of Loads

  • Purpose: Convert electrical energy into useful forms.

  • Examples of Loads:

    • Light Bulbs/LEDs: Change electrical energy into light.

    • Electric Motors: Change electrical energy into mechanical energy.

    • Speakers: Change electrical energy into sound.

Electrical Energy Sources

Source & Control

  • Electrical Energy Source:

    • Storage Battery

    • Generator

  • Role of the Switch: Interrupts current flow, allowing for control over electricity distribution.

Short Circuits

  • Definition: Occurs when an abnormally high amount of current flows in the network.

  • Causes:

    • Drop in resistance

    • Broken insulation

  • Prevention:

    • Use of Fuses: Melt when excessive current flows, opening the circuit.

    • Circuit Breaker: Protects against overloading, can be reset.

Comprehension Check

Questions for Review

  1. What causes a short circuit?

    • Abnormally high current due to resistance drop or broken insulation.

  2. Prevention of Short Circuits:

    • Use of fuses that melt during excess current flow.

  3. Role of Circuit Breaker:

    • Protect against circuit overloads, overheating, and short circuits.

Vocabulary Match

  • Load: Device consuming electric power.

  • Switch: Device controlling current flow.

  • Source: Provides electrical power.

  • Fuse: Protective device against excess current.

  • Closed Circuit: Complete circuit without breaks.

  • Broken Circuit: Circuit with disconnections.

Additional Vocabulary Review

Synonyms and Translations

  • Common Synonyms:

    • Abnormally: Unusually

    • Flow: Movement

    • Provides: Delivers

    • Interrupts: Disturbs

    • Occur: Happen

    • Drop: Descent

  • French Translations:

    • Terminal: Borne

    • Load: Charge

    • Amount: Quantité

    • Insulation: Isolation

    • Overloading: Surcharge

    • Overheating: Surchauffe

Terminology and Components

Structure of a Battery

  • Function: Converts chemical energy into electrical energy.

  • Components: Electrochemical cells with an electrolyte, cathode, and anode.

  • Common Types: Alkaline, lithium-ion, and nickel-metal hydride

Advanced Components

  • Potentiometer: Variable resistor used to control voltage/current, adjusts device brightness/volume.

  • Light Emitting Diode (LED): Emits light when electric current passes through.

Resistor Standards

Schematic Symbols

  • ANSI Symbol: Zigzag line for resistors.

  • IEC Symbol: Rectangle with two terminals.

  • Organizations:

    • IEC: International standards for electrical technologies.

    • ANSI: Oversees technical standards in the U.S.

Resistor Color Code

Reading Resistor Values

  • Typical Four-Band Resistor:

    1. 1st Band: First significant digit

    2. 2nd Band: Second significant digit

    3. Multiplier Band: Multiplies the value

    4. Tolerance Band: Variation percentage

  • Example: 52 MΩ with ±5% tolerance could range from 49.4 MΩ to 54.6 MΩ.

Current and Resistance

Key Electrical Concepts

  • Current: Measure of energy carried by charge, measured in watts/W.

  • Resistance: Restricts electric current flow, measured with an ammeter in series.

  • Power and Energy: Rate of using/supplying energy, often measured in kilowatt-hours (kWh).

Circuit Types

Series vs. Parallel Circuits

  • Series Circuit: Components connected end-to-end; current flows through all components.

    • Disadvantage: If one component fails, the entire circuit stops.

  • Parallel Circuit: Multiple paths for current; if one component fails, others continue to operate.

  • Application: Parallel circuits commonly used in household wiring to allow independent functioning of sockets.