Notes, summaries, assignments, exams, and problems for Technology

Resistors are fundamental electronic components classified into two main groups: fixed resistors and variable resistors. Understanding their types and characteristics is crucial for circuit design and analysis.

Fixed Resistors

Fixed resistors possess a unique, constant resistance value between their terminals. They are designed to maintain a specific resistance under normal operating conditions.

Types of Fixed Resistors

• Wire-Wound Resistors

  Manufactured by winding a resistive wire (often an alloy) around a ceramic cylinder. These are typically used for power applications (e.g., >2W) due to their ability to dissipate significant heat.

• Carbon Film Resistors

  Produced by depositing a thin film of carbon pyrolytically onto a ceramic cylinder. A small

Aircraft Safety Regulations

1. Never smoke in the lavatories.
2. Never store your bag above your head in the overhead compartment during takeoff or landing.
3. Never listen to a radio on the plane without headphones.
4. Fasten your seat belt when the "Fasten Seat Belt" light is flashing.
5. Never inflate your life jacket inside the aircraft.
6. Always know the location of your nearest emergency exit.

Engine Cooling System Description

The water is stored in the radiator and the engine jacket. It's pumped along the bottom hose from the radiator to the engine jacket. It flows through the engine jacket and the heater radiator to the thermostat. When the thermostat is closed, the water keeps going round the engine circuit. When it is open, the water passes along the top... Continue reading "Technical English for Industrial and Safety Applications" »

Metal Properties: An Overview

Oxidation: A chemical reaction where a substance combines with oxygen, often leading to corrosion in metals. While corrosion can be detrimental, it can also form a protective layer on some metals. The process may slow down or stop as the protective layer develops.

Corrosion: The gradual deterioration of metals due to a combination of oxygen and moisture, or chemical reactions with acids.

Mechanical Properties

Strength: A metal's ability to resist breakage or deformation under stress.

Elasticity: The property of a metal to return to its original shape after being deformed.

Yield Strength: The maximum force a material can withstand without permanent deformation.

Modulus of Rupture: The relationship between applied stress... Continue reading "Metal Properties: Oxidation, Strength, and More" »

Plastic Extrusion and Molding Processes

Extrusion profiles are used to create long, uniform sections. This process utilizes a specialized machine called an extruder, which operates similarly to a kitchen cutting machine. Plastic granules are poured into a feed hopper and flow into a chamber where a screw rotates. The extruder heats the plastic to between 150 and 250 degrees Celsius to soften it and force it through a die, creating the desired shape.

Extrusion and Blow Molding

Extrusion and blow molding are used for creating items like electrical lighting components, bottles, and toys. A hollow preform, called a parison, is extruded and then placed into a mold. Air pressure is then injected to expand the plastic, conforming it to the mold's shape.... Continue reading "Plastic Extrusion and Molding Processes: A Comprehensive Look" »

What is a Heat Engine?

A set of mechanical elements that exchange mechanical energy through the variation of the thermal energy of a fluid passing through them.

A set of mechanical elements that provide mechanical energy through the thermal state generated in a combustion reaction.

What is an External Combustion Engine?

Combustion occurs in a different working fluid and closed cycles, e.g., steam engines: steam engines, steam turbines, Stirling motors.

What is an Internal Combustion Engine?

Combustion occurs in the same fluid for work and open cycles, for example, reciprocating engines, rotary engines, gas turbines, turbojets.

What is a Volumetric Heat Machine/Motor?

Process with intermittent fluid friction, insignificant heat loss, pressure conversion... Continue reading "Understanding Heat Engines: Types and Inventors" »

Hot Water System Essentials

1. Tube Layout Characteristics: Pre-Use Checks

• Measuring diameter and wall thickness
• Analyzing galvanized steel tubing
• Testing hot water flow capacity (if applicable)
• Checking width
• Identifying accessory types

2. Tube Layout: Records Before Covering

• Ensuring no water leaks from joints under load tests
• Positioning hot water lines above cold water lines
• Maintaining minimum distances from other utilities:
  • 3 cm from gas pipes
  • 4 cm from other pipes
  • 30 cm from electrical lines

3. Types of Pipe Connections

• Concrete (with metal jacket): Double-shirt welding bead (interior and exterior)
• Steel: Thread, flange, or welding
• Cast Iron: Flange connection, automatic and mechanical joint gasket
• Polyvinyl Chloride (PVC): Screw joints, gluing, or ring

Water and Sewage

• Greywater: Waters that have been used in toilets, etc.
• Sewage: Waters that have been used to remove excrement.
• Downpipe: A conduit that carries wastewater to sewers.
• Distribution Network: Deals with the distribution of water ready to drink, called potable water.
• Siphon Outlet: U-shaped tube that always contains water to prevent the passage of odors.

Environmental Design

• Environmental Design: Aims to achieve thermal comfort inside a house naturally, taking into account the environmental conditions of the house and climate.

Broadband and Digital TV

• Broadband: A communication connection that allows faster data flow between sender and receiver.
• Decoder: A device that receives a signal and interprets it by offering a sound and signal that

Electronic circuits are fundamental systems designed to process information and manage electrical power efficiently.

Structure of Electronic Devices

Electronic devices typically comprise the following functional units:

• Input Devices: Provide the necessary information for the device to function.
• Processing Devices: Control the operation of the device based on the input information.
• Output Devices: Produce end effects, such as visual displays or sound.

These devices commonly include a housing, printed circuit boards (PCBs), and a power supply.

Key Electronic Components

Discrete Components

Discrete components are individual, fundamental units of an electronic circuit. They are categorized into two main types:

• Passive Components: These do not modify the

Composite Materials

Composite materials combine different components to achieve enhanced properties. Key types include:

Metal Matrix Composites

Arrays of metal, such as copper-alumina and titanium metal matrices, are used in aerospace applications with boron carbide and silicon carbide fibers.

Ceramic Matrix Composites

These are arrays of carbon graphite fibers used to improve the toughness of ceramics and maintain their properties.

Polymeric Matrix Composites

Polymeric matrices, like polyester with carbon fiber, provide flexibility and enhance the resistance of the fiber.

New Material Categories

Advances in materials research and manufacturing have enabled the creation of new materials from cheap and abundant raw materials, requiring less energy consumption.... Continue reading "Advanced Materials and Their Diverse Applications" »

IPL (Initial Program Load)

IPL (Initial Program Load) -> Power On Self Test (POST)

BIOS (Basic Input/Output System)

BIOS: A set of input and output routines. It handles the communication between the operating system and hardware.

Types of Memory

• RAM (Random Access Memory): For both reading and writing.
• ROM (Read-Only Memory): For reading only.

Types of ROMs

• ROM: Read-Only Memory.
• PROM: Programmable Read-Only Memory. A digital memory where each bit's value depends on a fuse that can be burned only once.
• EPROM: Erasable Programmable Read-Only Memory. Read sequentially. Less reading provides a greater margin for error.
• EEPROM: Electrically Erasable Programmable Read-Only Memory. The signal is updated and erased with the BIOS.

RAM and ROM Classification

• Dynamic