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

Simple Machines

Simple machines are basic devices formed by a single element. Their primary function is to multiply human force. Ancient philosophers identified five key simple machines: the lever, the wheel and axle, the inclined plane, the screw, and the wedge.

Types of Machines

• Drive Machines: These machines focus solely on producing motion.
• Operational Machines: These machines perform specific tasks, such as a vacuum cleaner.

Elements of a Machine

• Mechanisms: Moving parts that transmit motion to other machine components.
• Structure: Supports the mechanisms.
• Engine/Motor: Generates motion or force.

Force

Force is anything that can change the motion of a body or cause deformation. It is measured in Newtons (N). Approximately 0.1 N is the force exerted... Continue reading "Simple Machines and Mechanisms" »

Why Must an Ohmmeter be Calibrated When Changing Ranges?

What is Calibration?

An ohmmeter must be calibrated each time you change the measuring range to verify the proper operation of the instrument. When calibration is not performed, the needle may deflect incorrectly on the ohmmeter scale. Calibration involves measuring a known resistance standard and comparing it with the ohmmeter reading. This should be done at several points on the instrument's scale and for various scales.

Connecting an Ammeter to Measure Current Through a Resistor

Series vs. Parallel Connection

In which of the two forms mentioned would you connect an ammeter to measure the intensity of current flowing through resistor R? Justify your answer.

The correct way to connect an ammeter... Continue reading "Ohmmeter Calibration and Circuit Analysis Techniques" »

Closed-Loop Control System Components

Process

A continuous operation involving a series of systematic actions or changes designed to achieve a particular result. Common types include transformation, transport, and accumulation processes.

Primary Element of Measurement (Sensor)

An instrument that senses the variable to be measured. This variable can be physical or analytical, and sensors can be either intrusive or non-intrusive.

Transmission Elements

Devices that normalize and condition the sensor signal into a standard digital or analog signal, such as 4-20 mA electrical current, 1-5 VDC electrical voltage, or 3-15 psi (0.2-1 bar) pneumatic signals.

Indicator or Recorder

A device that provides a historical record of process variables over time, allowing... Continue reading "Closed-Loop Control Systems: Core Concepts & Components" »

When you need to make a motion transmission, you usually work directly with axes: We support a fixed, usually cylindrical axis, which serves as another element, such as a wheel or a pulley, to turn around. Tree: It's a bar, usually cylindrical, that transmits circular motion. Coupling: The element that allows joining two trees or two axes. Wheel Bearings: These are two completely smooth rim wheels that are in direct contact with one another for moving forward. Gearboxes: We have a minimum of two formed mechanisms, sprockets, constructed in such a way that matches the outgoing motion and transmits circular motion and power. Types of Gears: Cylindrical straight, helical, and bevel. A series of small items would not be possible without the proper... Continue reading "Understanding Motion Transmission Mechanisms in Machinery" »

Palmer Micrometer: Precision Measurement

A Palmer micrometer is a direct-reading measuring instrument. It provides the length value directly, enabling measurements with a precision of 0.01 mm and, in some models, 0.001 mm.

Micrometer Parts

• Body
• Tube
• Rotating drum
• Friction screw
• Circular graduation
• Linear graduation
• Brake
• Mobile probe
• Fixed and insulating probe handles

Micrometer Management

A micrometer can be used to measure parts on marble, on machines, or as support for serial investigations. The measurement procedure is as follows:

1. Open the tool to a range slightly greater than the dimension to be measured.
2. Position the piece between the probes.
3. Gently rotate the drum until the probes support against the piece. This should be done by acting through the

Heavy Work

This term refers to the part of a building's construction that includes the foundation, structural framework, walls, and roof girders.

Joist

A smaller beam, sometimes supported by principal beams or girders. In the context of poplar wood, this name also refers to the first piece carved with an axe from the tip of the trunk, typically 5 feet long.

Cuarton

This term indicates a piece obtained by sawing a whole tree crosswise. Generally, this name is given to sawn pieces with a thickness and width ranging from 2 to 6 inches.

Crowbar / Prop

This term can refer to:

• Vertical uprights or props used to support the formwork for concrete slabs and beams. Shims are often placed at their base to adjust the height.
• A sturdy lever or bar used for prying

Industrial Processes and Materials

Item 1: Production Cycle and Industry Types

1. The Production Cycle:

Industries can be classified into:

• Extractive Industries
• Processing Industries

2. Extraction of Raw Materials:

According to the type of resource:

• Mineral energetics
• Non-metallic rocks and minerals
• Hydrocarbons
• Plant and animal materials

3. Processing Industries:

• Steel and metal
• Petrochemicals
• Paper and artificial wood industries
• Textiles and leather
• Industrial ceramics, glass, and building materials

4. Automobile Manufacturing Process:

1. Realization of parts by melting and molding.
2. Union of parts by welding, adhesives, or threaded elements.
3. Realization of finishing by coating with paints, enamels, and varnishes.
4. Control, product warehousing, and packaging.

5. Saving

Camera Types for Video and Television

The camera's function is to capture the image. We can find a wide variety of video and television cameras, from cheaper designs to more sophisticated markets. We can find a great variety of models. When choosing a camera, several factors must be considered: price, practical aspects (e.g., weight), operational characteristics, and performance (image quality).

Studio Cameras

Studio cameras, for example, are used on set and are usually connected to a production control room. They create high-quality images. They tend to be large, bulky, heavy, expensive, and difficult to transport. They usually incorporate a prompter.

EFP Cameras

EFP stands for Electronic Field Production. These are lightweight cameras. Normally,... Continue reading "Camera Types and Supports for Video Production" »

**Plastic Materials: Properties, Types, and Manufacturing**

**Properties of Plastics**

Definition: Plastics are materials of organic origin, solid at room temperature, and easily molded by applying heat. They have a high molecular weight.

Most used: Polypropylene (PP)

Qualities:

• Weight reduction
• Noise damping
• Impact absorption
• Chemical resistance
• Corrosion resistance
• Thermal and acoustic insulation

Disadvantages:

• Low mechanical resistance
• Cannot withstand high temperatures
• Easily scratched
• Can easily capture moisture
• Sensitivity to sunlight
• Sensitivity to environmental conditions

**Chemical Processes**

Plastics are of organic origin and are chemical compounds formed by the union of several units. They can be formed by polymerization, polycondensation, or polyaddition.... Continue reading "Plastic Materials: Properties, Types, and Manufacturing Processes" »

Autoclave: Moist Heat Sterilization

Autoclave sterilization utilizes moist heat to effectively destroy spores, fungi, bacteria, and viruses. This process requires temperatures above 120°C. The autoclave chamber features a thick, stainless steel wall and a sealing lid. It includes a pressure gauge to monitor temperature and pressure, and a safety valve that activates when pressure reaches a dangerous level. A key controls the steam vent, enabling cooling. The tank contains water up to a specific level and a grid for placing objects. Heating can be electric or gas-powered.

Sterilization Phases in the Autoclave Process

Conditioning

Objects are placed on the grid, the lid is closed, and the vent key is opened.

Exposure to Vapor

The vent key is closed,... Continue reading "Autoclave and Ethylene Oxide Sterilization Methods" »