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

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

Electronic Communication Processes

In electronic communication, information in a signal moves from one device to another. Along the way, signals undergo a series of processes, including:

• Noise: The information signal gets mixed with other unwanted signals produced by highly diverse sources.
• Attenuation: This is the loss of energy a signal suffers as it propagates through a medium. This is resolved using amplifiers, repeaters, or signal regenerators at the transmitter and receiver.
• Signal Collision: A medium can be shared by several signals, but if they coincide, they collide and interfere with each other.

Denoising with Balanced Cables

This method consists of two conductors, where each carries the same signal but with opposite polarity to the other.... Continue reading "Signal Integrity in Guided Transmission Media" »

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" »

Fundamentals of Electrical Circuits

An electrical circuit is a closed path in which electrons circulate. A basic circuit includes the following elements: a generator that provides power, a wire, a switch, and a receptor.

The continuous circulation of electrons through a circuit is called electric current.

Circuit Components

• Generators: Necessary to provide the energy required for electrons to move (e.g., batteries).
• Receptors: Devices that convert electrical energy into another type of energy (e.g., light bulbs, motors, resistors).
• Control Elements: Utilized for directing and interrupting the electric current (e.g., switches, pushbuttons).
• Protection Elements: If the current is too high in a circuit, cables and components can overheat and melt or

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" »

Understanding Disk Partitioning

In computing, a disk partition is a division of a storage device, most commonly a hard disk drive. Partitions are formatted with specific file systems, such as FAT or NTFS. Physically, a disk is divided into cylinders, tracks, and sectors.

Types of Partitions

• Primary Partition: The main bootable partition.
• Extended Partition: A container for logical partitions.
• Logical Partition: A partition created within an extended partition.

Operating System Installation Process

To install an operating system, insert the installation media and reboot your computer. During startup, follow the on-screen prompts to select your partition, choose whether to reformat, and define the partition size. Once configured, the system will proceed... Continue reading "Disk Partitioning and Operating System Installation Essentials" »

Piston System Characteristics

• Irregular Wear: Piston Support & Cylinder Ovality

  The piston's support can cause the cylinder to become oval, leading to irregular wear patterns.

• Average Piston Speed Considerations

  Typically, average piston speed ranges from 10 to 15 m/s, though it should not exceed 8 m/s for optimal performance and longevity.

• CYP Ratio Parameters

  The CYP ratio usually falls within the range of 0.85 to 1.2.

• CH and CS: Direct Contact vs. Heat Transmission

  CH involves the vane in direct contact with liquid, while CS refers to heat transmission through other means.

• Piston Skirt Function: Guiding & Protection

  The piston skirt guides the piston's top movement and prevents it from hitting the cylinder head.

• Piston Temperature Zones: Crown

Fundamental Electrical Concepts

• Voltage (V): A characteristic of the energy source, indicating its ability to boost the flow of electricity along a circuit. It is measured in volts (V).
• Resistance: A feature of a receptor that measures its opposition to the passage of current. It is expressed in ohms (Ω).
• Current Intensity (I): Indicates the number of electrons circulating per second at any point in a circuit. It is expressed in amperes (A).
• Electric Energy: Consumed by a receptor, expressed in kilowatt-hours (kWh) and calculated using the formula: E = V · I · t.
• Electric Power: Of a receptor, expressed in watts (W) and calculated using the formula: P = V · I.

Types of Electric Current

• Direct Current (DC): Always flows in the same direction, generated

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

Rotary Engine Mechanics

How the Wankel Engine Functions

The triangular rotor rotates on an eccentric located on the motor shaft or output shaft. During its rotation, the three vertices of the rotor remain in constant contact with the inner surface of the epitrochoidal-shaped housing. The rotor describes orbits around a stationary pinion gear. The rotation of the rotor is transmitted to the drive shaft at a 3:1 ratio; for every three turns of the rotor, the shaft completes one revolution.

Each of the three chambers formed between the rotor and the housing undergoes a 4-stroke cycle. In one turn of the rotor, three complete cycles occur per rotor revolution. This means the engine receives a power pulse every 120 degrees, utilizing intake and exhaust... Continue reading "Rotary Engine Mechanics: How the Wankel System Works" »