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

Mass Media

Mass media refers to channels used to transmit messages to large populations, such as newspapers, radio, and cinema. Our society relies heavily on their constant presence.

Characteristics of Mass Media

• Complex technology requiring specialized professionals.
• Collective receivership (messages reach multiple people simultaneously).
• Primarily unidirectional communication (limited feedback from receivers).

Mass media are powerful instruments of social influence, serving three main purposes: informing, shaping public opinion, and entertaining.

Verbal and Nonverbal Codes

Each medium employs unique communicative codes. For example, the press utilizes images, headlines, and text layout, while television incorporates sets, gestures, and music.

Television

Television... Continue reading "Mass Media and Dialects of Castilian" »

Rigid Couplings

Rigid couplings are those which have a rigid connection between the two axes. Generally, they are built with two plates that are joined together by means of screws. They do not allow any relative movement between the two elements joined.

Torque Limiters

Torque limiters are rigid, maintaining the transmission of the effort while not exceeding a certain value. The most basic are constructed by a cross pin which is sheared when the torque limit is exceeded. They are simple and economical but have the disadvantage of being removed each time they are sheared. They are used as security features.

Elastic Couplings

Elastic couplings are those that allow some relative movement between the two axes united. Therefore, they have some elastic... Continue reading "Mechanical Couplings and Clutches: Types and Applications" »

Active Safety Systems

Active safety systems aim to prevent accidents, ensuring vehicle operation is as safe as possible on the road or in any situation. They contribute to the vehicle's active safety in addition to factors that increase running safety (such as suspension, steering, and brakes). This also includes the design of the body, which takes into account driver visibility, and seats manufactured properly to fit the body and avoid fatigue.

Passive Safety Systems

Passive safety systems condition the manufacture of all components of the passenger compartment so that, in the event of an accident, they reduce damage to passengers or prevent injuries. Active systems are engaged at the time of an accident (e.g., ABS, airbags), while passive systems... Continue reading "Car Safety Systems: Active, Passive, Airbags" »

Understanding Programmable Logic Controllers (PLCs)

A Programmable Logic Controller (PLC) is an electronic device capable of processing analog variables, digital, numeric, and alphanumeric information. PLCs are designed for real-time monitoring and control of automated industrial processes.

External circuits consist of sensors, which send information from the industrial process to the automaton, and actuators, responsible for executing the program's commands.

PLC Memory

The primary function of PLC memory is to store program instructions, data, internal states, and input/output states. PLC memory is typically organized into distinct work areas.

Memory Types

• RAM (Random Access Memory): Read-write memory. In the absence of power, information volatilizes

Asynchronous Machine Analysis: Torque, Fields, and Braking

Starting Torque and Stator Connection

Q: Demonstrate the relationship between the starting torque of an asynchronous machine with the stator connected in a triangle, being three times higher than the same machine with the star-connected stator.

Ta star = (1 / √3)² Tb

Ta = 1 / 3 Ta

Ia star = 1 / 3 Ta

The starting current in star is 1/3 in a triangle, reducing starting torque to 1/3.

Magnetic Field and Rotor Speed

Q: Demonstrate that the magnetic field produced by the stator currents of an induction machine turns at the same speed as the magnetic field produced by currents induced in the engine.

The connection speed of the stator field created by the rotor is the sum of the speed but the torn... Continue reading "Asynchronous Machine Torque, Magnetic Fields, and Braking Analysis" »

Electromagnetic Waves

6. Wave: electromagnetic vibration propagating through space.

• Length (m): Distance from the beginning until it repeats.
• Width (m): Maximum height.
• Frequency (Hertz): Wave quantities per second.

Voice Transmission

7. Voice (microphone) → cable → electrical signal transmitter → antenna (emits waves) → wave → electrical signal → antenna captures → voice.

Am: Amplitude Modulated.
FM: Frequency modulation.

Digital Terrestrial Television (DTT)

8. Television is accessible to all with DTT, offering optional paid content.

• Eliminates image defects and snow effect.
• Improves picture quality and sound.
• Allows subtitle and language selection.
• Offers interactive and multimedia services.
• Enables real-time traffic, statistics, surveys,

Communication is the process by which a sender transmits a message to a receiver.

A sign is something (a set of sounds, a figure, a light) which suggests the idea of something else.

Schematic Diagram of Communication:

• Issuer: The one who prepares and sends the message.
• Receiver: The one who receives and interprets the message.
• Message: The information that the sender transmits.
• Context: The set of circumstances surrounding the communication.
• Code: The sign system used to develop the message.
• Channel: The medium that carries the message (visual, auditory).

Text: A complete message that is transmitted orally or in writing.

Classes of Texts:

According to the communicative intention, we can distinguish four types of texts:

• Informative: Aim to facilitate new

Understanding Control System Controllers

Core Components of a Control Loop

In a control and regulation system, we can distinguish the following elements:

• Transducers and sensors
• Comparators and error detectors
• Control and regulation elements
• Final elements or actuators

The controller is the 'brain' of a control loop. It is responsible for comparing a physical variable with the desired value (setpoint), interpreting the error or deviation, and acting to minimize or eliminate this error. While the controlled variable is maintained at the expected value, the controller does not act on the final elements. If the control variable deviates from the setpoint, the controller modifies the signal acting on the final elements to correct this deviation, continuing... Continue reading "Understanding Proportional, Integral, and Derivative Controller Actions" »

Lesson 1

Hydropower Plants: Using the energy generated by the water stored in a swamp to a steep fall on the turbine that mechanically turns the electric generator, which produces electricity.

Nuclear and Thermal Power: Using steam at pressure on the turbines that drive the electric generator. In thermal power, steam is produced by combustion, while in nuclear power, a controlled nuclear reaction with uranium is used as fuel.

Wind Farms: Exploits the kinetic energy of wind for electric power generation by grouping several wind generators.

Photovoltaic Power Plant: It can generate electricity by exploiting the energy from photovoltaic cells that capture sunlight.

Charles Coulomb enunciated what is known as Coulomb's Law to demonstrate experimentally... Continue reading "Understanding Power Generation: Key Concepts and Principles" »

Understanding Electricity Billing

Let's break down the components of your electricity bill:

• Power Term (T. potencia): A fixed amount paid in billing, determined by the contracted power.
• Energy Term (T. energia): The amount paid for the actual energy consumed.

Types of Electricity Rates

• Last Resort Rate (TUR): Replaces the former "integral rate," set by the government. It features a single price for all users. Available for those with contracted power less than 10kW.
• Toll-Free Rate: You can negotiate different conditions than the TUR with a marketer.
• Access Fee: Covers the cost of using the distribution network to bring electricity to your home. Not applicable if you have the TUR.
• Social Bond: A tariff designed to protect households with fewer resources.