Notes, summaries, assignments, exams, and exercises for Technology for Vocational training

Fundamentals of Informatics

Informatics is the branch of technology that studies the automatic treatment of information by computers.

Core Components of a Computer System

Hardware

Hardware refers to all physical and electronic parts of a computer.

Software

Software is composed of the operating system and application programs (a set of instructions), for example, text processors or games.

Computer Types

Common types of computers include:

• Desktop computer
• Notebook computer
• Computer room (Workstation/Server)
• Pocket computer

Internal Hardware Structure

The Case (Chassis)

The Case (or frame) incorporates the main structural elements and houses components like the motherboard.

The Motherboard

The Motherboard is an electronic board featuring a set of circuits, connectors,...

Laying Ground Facilities Project

The process involves several key steps:

• Research
• Determination
• Design
• Calculation of resistance
• Computation step of crack on the outside of the installation
• Calculation of contact and step voltages inside the installation
• Checking
• Research
• Correction

Wenner Method

The Wenner method is the most used and recommended technique to measure the resistivity of the ground.

High Voltage Open Circuit Procedure

1. Open the switch.
2. Open the disconnectors.

High Voltage Circuit Closing Procedure

1. Close the disconnectors.
2. Close the switch.

Lockout or Interlock Device

A lockout or interlock device is the set of operations aimed at preventing the operation of a device and maintaining it in a given position.

Verification of Absence of Tension

It is necessary...

Understanding Cyber Threats and Security Measures

1. Malware: Any malicious program or code that is harmful to systems.

2. Trojan Horse: A Trojan horse is a program that appears harmless but is, in fact, malicious. Unexpected changes to computer settings and unusual activity, even when the computer should be idle, are strong indications that a Trojan is residing on a computer. It is not able to replicate itself.

3. Worm: A computer worm is a standalone malware computer program that replicates itself to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Worms almost always cause at least some harm to the network.

4. Spam: Spam refers to unsolicited, unwanted,...

Electric Brake Dynamometer

The electric brake dynamometer transforms energy absorbed from the engine into electrical energy, unlike hydraulic brakes which convert it into heat. It consists of a stator (or inductor) that can pivot on a support resting on the bench via ball bearings, allowing for damping fluctuations around a shaft attached to the rotor (or armature) of the dynamo. The housing is mounted on a lever arm that collects the load weight, which determines the resistance torque measured on the dynamometer. On the opposite side of the housing, an extension of the lever arm carries a counterweight to balance the machine at rest.

Prony Brake: A Historical Perspective

The Prony brake is the simplest and most rudimentary dynamometer, and it...

Plastic Repair Methods

Plastic repair can be achieved through various techniques, including acetone welding, thermal welding, and structural adhesion.

Thermal Welding

Thermal welding involves applying heat to soften the material. Note that you may only weld nature-identical materials (same plastic type).

Equipment

• Air welder
• Speed welding nozzle or wedge
• Rotary cutter
• Support and safety rods

Operation

Connect to the power source, adjust temperature and airflow, position the nozzle, and allow the device to warm up.

Welding Steps

1. Identify plastic type
2. Surface preparation
3. Crack prevention
4. Material restoration
5. Welding preparation
6. Tack welding
7. Filler material application
8. Pendulum welding
9. Surface matching
10. Painting

Preparation of Welding

1. Remove paint 10–15 mm around the

Hydraulics Fundamentals

Hydraulics studies the balance and movement of liquids and their application in circuits that use liquids as fluid. Principal characteristics:

• They have no shape.
• Incompressible.
• Transmit pressure in all directions.
• Multiply the force applied.

Hydraulic Press

With a small force applied to the lower piston, you can get great efforts on the larger piston.

Hydraulic Pumps

Hydraulic pumps produce a shift of fluid flow from the tank or to another point in the circuit.

Types of Displacement:

• Nonpositive Displacement: Move the liquid velocity increasing in the circuit.
• Positive Displacement: Move the liquid flow generated.

Flow pumps can have fixed or variable displacement.

Gear Pumps

Gear pumps are fixed displacement pumps. There are external...

Serrated cutting is a metal removal operation that can divide a piece into two or more parts by removing material between them. The manual process consists of the sawing and the forward movement of the saw. The effectiveness depends on operator skill and the number of sawing strokes per second.

Bow or Frame

This tool supports the saw blade. It consists of a rigid, U-shaped arch. At the ends of the arch are two mutually perpendicular blocks that hold the saw. One of these blocks is controlled by a mobile or wing nut, and a handle serves as a grip.

The arches of saws can be fixed or extensible. The advantage of the extensible type is that it allows the assembly of saw blades of various sizes.

Saw Blade

A saw blade is made of thin, laminated carbon...

Mechanical Properties of Metals

Mechanical properties are the properties that express the behavior of metals under forces aimed at altering their shape. A summary of the different types of fundamental forces to which any structure or machine can be subjected are: tension, compression, shear, bending, torsional buckling, or a combination of these.

Resistance

Resistance is the ability of a metal to withstand an external load of the types mentioned above without breaking. As each load type has its corresponding resistance, it is usual to work with a resistance lower than that which would cause breakage in the plastic period of the material, i.e., working within the elastic period.

Hardness

There are two types of hardness: physical, which is the ability...