Notes, summaries, assignments, exams, and exercises for Technology for Secondary education

Hardware: Physical components of a computer, including electronic circuits and electromechanical devices.

Software: Logical programs that enable computer functionality, such as word processors and email clients.

Operating System: A core program that manages the execution of other programs and serves as an interface between the user and the computer hardware. Key properties include comfort, efficiency, and capacity evolution.

• Windows and Linux feature both graphical environments and command-line interfaces.

Hard Disk: Stores computer data and comprises plates, a motor, and a read/write head.

• Partition: A logical division of the hard drive.
• Defragmentation: Optimizes the hard disk by reorganizing data, reducing the time it takes for the computer to

Metrology and Measurement Fundamentals

Metrology is a theoretical science and practical discipline covering the context of measurement.

Parallax Error

Parallax error is avoided when reading the scale by positioning your view perpendicular to the vernier scale. Reading at an angle introduces considerable errors.

Caliper

A caliper is an instrument used to measure linear dimensions such as internal, external and depth dimensions of a workpiece. It consists of a graduated ruler with a fixed jaw, on which a sliding jaw moves.

1. Fixed ear
2. Movable ear
3. Vernier scale (inch)
4. Locking screw
5. Slider
6. Fixed inch scale
7. Fixed jaw
8. Fixed stop
9. Movable stop
10. Movable jaw
11. Vernier scale (mm)
12. Depth probe
13. Fixed millimeter scale

Types of Calipers

The quadrimensional caliper is used for internal,...

The Digital Revolution and the Internet

The digital revolution, including the Internet and ARPANET, is built upon three foundational technological breakthroughs:

• Microprocessors
• Data transmission at the speed of light
• Compression and coding systems that allow information to be represented and sent as binary values.

The Origins of the Internet

The origins of the Internet date back to 1968 during the Cold War. The U.S. Department of Defense created a research agency with a mandate to develop a system capable of preserving information in the event of a nuclear attack. This led to the creation of ARPANET, which digitized information for transmission via telephone cables.

Initially intended for the military, the system was later made available to the scientific...

Electronic Systems and Signal Processing

An electronic system captures information from the outside world (such as sound or light), converts it into electrical signals, processes it, and transforms it into another energy source to produce a specific effect.

Types of Signals

• Analog Signals: Continuous signals that can take an infinite number of values.
• Digital Signals: Discrete signals that exist only at specific moments and take specific values, usually transmitted in binary.

Capacitors

A capacitor consists of two parallel metal plates separated by air or another material called a dielectric. Its function is to store electrons and release them when necessary. The amount of energy it can store is called capacitance, measured in farads.

• DC Behavior:

What Is an Electron?

An electron is a subatomic fermionic elementary particle.

Relationship With Electricity

Electrons carry a negative charge; their movement through a material conducts electricity.

What Is Electric Current?

Electric current is the flow of charge per unit of time (per second) traveling through a material.

Types of Current

• Direct Current: Electrons flow in the same direction.
• Alternating Current: Electrons change direction 50 times per second.

Ohm's Law

Ohm's Law defines the relationship between voltage, current, and resistance:

• R (Resistance): Measured in ohms (Ω). Formula: R = V / I
• I (Intensity/Current): Measured in amperes (A). Formula: I = V / R
• V (Voltage): Measured in volts (V). Formula: V = R × I

The Electric Circuit

An electric...

Thermal Machines: Converting Energy into Mechanical Work

Thermal machines, also known as heat engines, are machines that transform thermal energy (heat) into mechanical energy.

Types of Heat Engines

Heat engines are classified into two main groups according to where combustion takes place:

• External combustion engines: the fuel burns outside the machine. The heat is transferred to a working fluid, usually water, which boils and turns into steam.
• Internal combustion engines: the fuel burns inside the machine. The combustion gases are the working fluid that directly produces mechanical work.

External Combustion Engines

These engines can be:

• Alternative (reciprocating): for example, the steam engine.
• Rotary: for example, the steam turbine.

Internal Combustion

Resistance: Opposition to offer the components of a circuit when current flow is the ohm eléctrica.Medida. The fixed resistors: The electrical resistance is the difficulty posed by the materials to the passage of electrical current. In electronic circuits we use these components to limit or regulate the amount of current flowing through a given circuit, so as to protect some components that should not circulate a high current intensity. Resistances variables (potential): The potentiometers vary their resistance between zero ohms (Ù) and a maximum value which is indicated on the component. To vary the resistance value is necessary to turn a shaft or move a cursor. Example: the volume control of a radio or the remote control speed of a car...

Key Metallurgy Concepts

Ore and Gangue

Ore refers to the useful part of a mineral, while Gangue is the unused portion of the mineral.

Metallurgy Defined

Metallurgy is the set of industries responsible for mineral extraction and metal transformation.

Types of Metals

Ferrous Metals

Ferrous metals are materials whose major component is iron, such as pure iron and steel foundries. Steel is a branch of metallurgy that works with ferrous materials.

Non-Ferrous Metals

Non-ferrous metals are materials that contain no iron, or contain iron only in small quantities. Examples include copper, brass, and bronze.

Alloys

An alloy is a mixture of two or more chemical elements, at least one of which is a metal and is found in greater proportion.

Properties of Iron

Iron...

Pneumatic Systems: Principles and Applications

Pneumatic refers to all techniques involving the use of compressed air as a fluid to transmit energy for machines and mechanical mechanisms.

Advantages of Pneumatic Systems

• No risk of sparks, making them safe for hazardous environments.
• Air is easily and abundantly available.
• It is a clean fluid.
• Easy to store in tanks.
• Rapid movement through conduits.

Basic Elements of Pneumatic Installations

1. Production

• Compressors: Rotary machines driven by electric motors or internal combustion engines (petrol or diesel). They take atmospheric air and compress it to a higher pressure. They are the central element of the installation.
• Coolers: Heat exchangers, typically consisting of a series of tubes through which a

Fundamentals of Structures

What is a structure?

A structure is a group of elements united to support a load.

What is a force?

A force is anything that can deform a body or modify its state of rest or movement.

What is a load?

Loads are the forces that a structure must bear.

Types of structural loads

Loads are categorized as either fixed or variable.

What is an effort?

An effort is the internal force experienced by the elements of a structure when subjected to external forces.

Types of structural efforts

The primary efforts are: Tension, Compression, Shear, Torsion, and Bending.

Conditions for a stable structure

A structure must possess three key conditions: rigidity, stability, and resistance.

• Rigidity: Achieved through triangulation.
• Stability: Achieved by