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

Materiais Téxtiles

Os materiais téxtiles poden ser naturais ou sintéticos. As fibras naturais extráense de materias primas de orixe animal, vexetal ou mineral.

Fibras de Orixe Natural

Orixe Vexetal

Algodón: Provén do froito da planta do mesmo nome, da familia das malváceas. Aínda que a súa cor natural é branca, pode tinguirse de moitas cores. É elástico e flexible, bo illante térmico, resistente aos ácidos, lixeiro e permeable.

Liño: Obtense do talo da planta do mesmo nome, da familia das lináceas. A súa cor natural é branca ou castaña. É suave, flexible, bo condutor térmico e resistente ao cloro e á lixivia.

Esparto: Extráese das follas dunha planta herbácea. É moi resistente e tenaz. Emprégase na industria do calzado,... Continue reading "Propiedades e Aplicacións de Materiais Naturais e Sintéticos" »

DC Machine Types

Field or Parallel Shunt

• Field winding with many turns
• Small wire cross-section
• High resistance
• High inductance
• Field current is 1 to 4% of Inom

Field Series

• Low resistance
• Large cross-section
• Few turns
• Low inductance

Compound or Series and Parallel

• Part of the field is in series
• Low resistance
• Large cross-section
• Coils with few turns
• Low inductance

Independent Excitation

• Used for servo applications
• Auxiliary fields for weak-field switching
• Interpolate and is connected in series with armature
• Instability at high speeds
• Field-stabilizer used in shunting engines, connected in series with the armature

Control System

A control system is a device or group of devices used to control the operation of one or more electric machines.

Types of Diagrams

Connection

Technology, Materials, and Processes

Technology seeks to meet human needs by creating artificial objects. It involves the study of materials, technical skills, and work organization.

Materials are consumed in a process. They are used once and then depleted.

Tools are not consumed in a process. They can be used repeatedly and experience little to no depletion.

Inventing is creating an object for the first time.

Innovating is improving an object that already exists.

Discovering is finding something that existed but was previously unknown.

Craftsmanship involves creating objects with few or many people. These objects are unique because they are handmade with limited tools and tend to be expensive.

Industry involves many people, resulting in identical... Continue reading "Technology, Materials, and Processes: A Comprehensive Look" »

Broadband Connections: To transmit the large volume of data sent via the Internet, the majority of primary networks are comprised of fiber optic cables. In the early Internet, the analog electrical signal coming through the telephone line was received and converted to a digital format accessible by a device known as a modem. The increasing power of personal computers and the growing number of users accessing the Internet have created the need to expand the capacity of connections that were developed. Broadband connections, the chief of which is the ADSL technology, allow Internet users a direct connection to the server. On an ADSL line, there are three communication channels: the delivery of data, data reception, and normal telephone service,... Continue reading "Understanding Broadband Connections and Digital Technology" »

Pneumatics

Pneumatics is a set of techniques based on the use of compressed air as a fluid for transmitting energy for the operation of machines and mechanisms. It is used because it does not emit sparks, is readily available, is a clean fluid, is easily stored, and moves quickly inside conductions.

Hydraulics

Hydraulics is a set of techniques based on the use of mineral oil as a fluid for transmitting energy for the operation of machines and mechanisms. Mechanical applications of hydraulics transmit small and large efforts and achieve the most varied movements.

Advantages of hydraulic systems include:

• Easy control of speed
• Powerful transmission
• Position control
• Reversibility of the drives
• System protection
• Noise reduction
• Possibility of starting and

Television Control Systems & Components

Core Functions of TV Control Systems

• Q: What are the specific functions of a television's control system?
• A: The control system is designed to obey user commands, offer practical solutions to problems, and optimize color display.
• Q: Is there a function that allows TV surveillance?
• A: This refers to the suspension aspect of operation.
• Q: How were televisions presented in past years?
• A: They featured digital compatibility.
• Q: What was the manufacturer's purpose in introducing a TV receiving phase?
• A: To facilitate television reception for the user.

SYSCOM and Microcontroller Operations

• Q: What are three functions of the SYSCOM?
• A: SYSCOM functions include increasing operational speed, ensuring accuracy, and preventing

Key Concepts in Modern Technology and Materials

Nanotechnology Explained

Nanotechnology is an applied science that focuses on the design, manufacture, and application of materials and equipment at the nanoscale.

Key Aspects of the Second Industrial Revolution

• New production systems emerged.
• Production improvements accelerated significantly.
• Transformative changes occurred in production methods at all levels.
• Minimization of production costs became a focus.
• Global transformation was evident.

Understanding Semiconductors

Semiconductors are materials whose conductivity can be varied, typically by changing the temperature at which they operate. The most important examples include silicon and germanium.

Innovative Materials and Technologies

• Fabrics that are

Chalcolithic Material Characteristics

Bell-shaped vessels were common, known for their good cooking properties and profuse exterior decoration. Smaller vessels sometimes featured interior decoration as well. The exterior typically displayed alternating smooth and decorated horizontal bands. Lower triangular motifs sometimes incorporated radial patterns when viewed from below, while the lip featured narrow bands with more complex decorations. Vertical band developments were also present. Some bands were filled with parallel oblique lines, oblique lattice patterns, or left undecorated. Printed series of spikes were also observed. The arrangement and combination of decorative motifs varied depending on the specific type, such as troughs, Ciempozuelos,... Continue reading "Chalcolithic Artifacts: Pottery, Arrowheads, and Idols" »

Hydraulic Pumps: Boosting Suction and Discharge

• Constant High-Pressure Flow: A moving part (piston) is housed inside a casing.
• External-Tooth Gear Pump: Reverse rotation occurs at the entrance. There is a negative pressure difference that allows the transfer of the deposit to the inlet of the pump.
• Internal-Tooth Gear Pump: Features external teeth on the driving gear and internal teeth on the driven gear, along with a crescent-shaped plate.
• Lobe Pump: Similar to an external-tooth gear pump but designed for constant flow (unbalanced).
• Unbalanced Vane Pump: The rotor rotates within the volumetric ring and is located eccentrically.
• Balanced Vane Pump: The rotor and the ring are concentrically arranged, creating two zones of aspiration and discharge.

Resistors: Limiting Current Flow

Resistors are fundamental electronic components that limit and regulate the amount of current flowing through a given circuit. They protect other components by ensuring that a very high current does not circulate through them.

Types of Resistors

Fixed Resistors & Tolerance

Fixed resistors have a constant resistance value. Their tolerance indicates the maximum deviation from their stated value, expressed as a percentage. This value is typically indicated by the first three bands or digits on the component.

Variable Resistors: Potentiometers

Potentiometers are variable resistors commonly used in electronic circuits to create adjustable voltage drops or to control current. Their resistance can be manually changed.... Continue reading "Fundamental Electronic Components Explained" »