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

Essential Electronic Components

Relays

Relays are components used to control a high voltage current by means of a small current applied to a coil. When an electric current passes through the coil, it acts like an electromagnet and attracts a movable piece of metal that closes two contacts. If an electric current doesn't flow through the coil, the central contact stays joined to the contact on the left.

Capacitors

These are components that can store electric charge. They are made of two conductive plates separated by a non-conductive material called a dielectric. There are two kinds of capacitors: electrolytic and non-electrolytic capacitors. Electrolytic capacitors have terminals of different lengths, while non-electrolytic capacitors have terminals... Continue reading "Essential Electronic Components: Relays, Capacitors, and More" »

Gears: Basic Concepts

1. What are gears and what are they used for?

They are mechanical elements designed to transmit turning movements.

2. What does it mean when two gears "engage"?

It means their teeth fit into those of another similar wheel.

3. What are the two main characteristics of gears? How are they represented?

The two main characteristics are the number of teeth (Z) and the rotational speed (N).

4. What happens if two gears have a different number of teeth? And if they have the same number?

• If they have a different number of teeth, the smaller gear rotates faster than the larger gear.
• If they have the same number of teeth, they rotate at the same speed.

5. In a pair of gears, what role does the motor gear have? And the output gear?

• The motor

Understanding Levers: Simple Machines

What is a Lever?

Levers are simple machines. They are made up of a rigid bar and a point of support, which is also called a fulcrum. They are normally used to exert a large force using only a small force; they are a type of force multiplier.

Key Elements of a Lever

Resistance is the force that must be overcome by the applied force. The point of support, or fulcrum, is the point about which the lever swings. The arms, the force arm and the resistance arm, correspond to the distance between the fulcrum and the applied force or resistance, respectively.

• The force arm is the distance between the fulcrum and the applied force.
• The resistance arm is the distance between the fulcrum and the resistance.

The Law of the

Computer Hardware and Usage: Q&A

Basic Computer Knowledge

1. What is a Bus?

   A bus is a device that determines how much data can be transmitted.

2. What Does She Look Like?

   She is beautiful, medium tall, with brown hair.

3. How Tall Are You?

   I am tall, one meter and seventy-four centimeters.

4. What is a Motherboard?

   The motherboard is the hub used to connect all the essential components of a computer.

Input and Output Devices

5) Define input and output device

An input device is a peripheral used to provide data and control signals to an information processing system.

An output device is any piece of computer hardware used to communicate the results of data processing.

RAM vs. ROM

6) What is the difference between ROM and RAM?

ROM: Access to memory information... Continue reading "Computer Hardware and Usage: Q&A for Students" »

**Protection and Indirect Contacts**

Luminaires shall be Class I or Class II. Accessible metal parts of the luminaires will be connected to the ground. Excluded from this requirement are those metal parts with double insulation that are not accessible to the general public. For access to the interior of luminaires installed at a height less than 3 meters above the ground or in a publicly accessible space, the use of special tools will be required. All metal structures within a distance of less than 2 meters from the metal parts of the exterior lighting installation shall be joined together equipotentially. It must be ascertained whether these metallic elements can transfer dangerous voltage points to a distance (e.g., metallic). In which case,... Continue reading "Safety and Installation Standards for Outdoor Lighting" »

1. Construction Machinery Administration

R: Administration is essential for optimal operation of construction machinery in all relevant processes.

2. Machine Definition

R: A machine is a set of moving and fixed parts that leverages, manages, regulates, or transforms energy to perform work.

3. Machinery Definition

R: Machinery refers to a set of machines with a common purpose and the mechanism providing motion.

4. Machine Components

R: The main components are: Motor, mechanism, chassis, and safety components.

5. Motor

R: The motor converts energy to perform the required work.

6. Mechanism

R: The mechanism is a set of mechanical elements, some mobile, transforming motor energy into the desired output.

7. Chassis

R: The chassis is the rigid structure supporting... Continue reading "Construction Machinery Management and Classification" »

Workplace Safety and Health

Royal Decree 486/1997, April 14: Safety and Health Provisions in the Workplace

Article 4 - Construction Conditions

The design and construction features of the workplace must provide security against risks of falls, blows, landslides, or materials falling on workers. The design and construction features are required to provide emergency exits or fire escapes.

Article 8 - Illumination

Lighting must be sufficient so that workers can see and carry out their work safely.

The construction of the store should be safe, with secure electrical installations and no vibrations that could damage the material. The design must provide safety against falls, crashes, collapses, or falling materials. Risk areas with potential falling objects... Continue reading "Workplace Safety and Material Handling in Storage Facilities" »

X.25 Networks

X.25 is a standard for wide area network (WAN) packet switching. It establishes mechanisms for routing between users, negotiation of communication features, and error recovery techniques. Public packet-switching services support numerous types of stations from different manufacturers. Therefore, it is of utmost importance to define the interface between the end user's computer and the network.

Levels of X.25

• Physical Level: The recommendation for the X.25 packet level coincides with one of the recommendations of the third level of the OSI model. X.25 encompasses the third level and also the two lowest levels.
• The Link Layer: In X.25, it is assumed that the link layer is LAPB (Link Access Procedure, Balanced). LAPB is responsible for

Understanding Malware Threats

Malware encompasses any program, document, or message that can harm your computer. This harm can include deleting data, slowing down performance, or causing programs to malfunction.

Types of Malware

Viruses

A virus is a program that installs itself on your computer without your knowledge. Its primary purpose is to spread to other computers and execute malicious actions.

• Objectives: Affect the integrity and availability of data and software.
• Affected Elements: Data and software.
• Solution: Antivirus software (scanning, file checking, and resident protection). Prevention, detection, and recovery are key.

Trojans

Trojans are small applications disguised as utility programs, images, or messages. Their purpose is to create a... Continue reading "Understanding Malware: Viruses, Trojans, Worms, and More" »

Fluid Mechanics: Definition and Characteristics

A fluid is a gas or liquid whose particles do not maintain sufficient attraction between them and move freely. When a force is applied, they slide over each other. Key characteristics include flow, spill, and the ability to move through pipelines.

Pneumatic Circuits: Components and Function

A pneumatic circuit performs work using the energy gained by pressurizing a gas, usually atmospheric air. It consists of:

• Compressor: Creates air pressure.
• Tank: Stores and cools the compressed air.
• Storage Unit (filter, lubricator, and pressure gauge): Conditions the air.
• Pipes: Distribute the air.
• Cylinders: Perform the work.
• Valves: Control the airflow to the cylinders.

Hydraulic Circuits: Principles and Components

A... Continue reading "Pneumatic, Hydraulic Circuits, and Water Systems" »