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

Technology: Creating Practical Solutions

Technology is creating practical solutions to satisfy human needs and problems.

Factors in the Technological Process

Physical and scientific concepts

Technical drawing

Materials and their properties

Work techniques

Economic factors

Information technology

Stages of the Technological Process

Needs and problems

Collecting information

Designing (drawing)

Planning (materials-tools-time-money-people in charge)

Building

Evaluating and checking

Writing a report

Materials for technical use

Resolution and Sensitivity

Resolution = MaxV / (2^bit - 1).

Linear Potentiometer

Total Resistance = 800 Ohms, E = 2V, L = 10 cm.

Sensitivity = V/L. Max/Min Z.

Z_out = || 80{10 - |x|}.

Z_min = 0 Ohms.

Z_max = 400 || 400 = 200 Ohms.

Unknown input impedance = voltage follower.

Gauge Factor

20mm wire strain gauge resistance = 150 Ohms. Under force tension, R changes by 5, and L changes to 0.08.

Load Cell

Load Cell Sensitivity / Minimum Value of N.

LC makes a change in V from 0 to 2V. V varies linearly.

LCS = 2V / 10N = 0.2 V/N.

Minimum Value of N = 10N / 0.1N = 100, 2⁶.

Filters

IIR Filter Identification

Unbounded, non-causal.

IIR/Unbounded. y[n-1] = 200x[n] + 300x[n-1] - 500x[n-2]. Non-causal.

Digital-to-Analog Conversion

N-bit R-2R Ladder

V = 0/6.4. n = 5.

Maximum V_out... Continue reading "Understanding Sensors, Filters, and Data Conversion" »

Solid Bulk Terminals

As the name implies, solid bulk terminals handle bulk cargo and are typically located near port entrances.

Design

These terminals don't require a continuous berth. The current trend is to construct them with a light working platform.

Goods

Solid bulk terminals handle various goods, categorized as follows:

• Primary Bulk Cargo: Iron ore, cereals, coal, bauxite, and phosphates.
• Secondary Bulk Cargo: Metals, minerals for construction (coke, cast iron, cement, magnesium ore, scrap), and other agricultural products.

Storage

Storage methods depend on the cargo type:

• Clean Bulk: Products for human or animal consumption (cereals, flour, animal feed) require specific handling and storage facilities.
• Dirty Bulk: Materials from mining and steel

Teen Room Essentials

Furniture

• Chest of drawers: A piece of furniture with drawers in which you keep things such as clothes.
• Cushion: A bag made of cloth, plastic, or leather that is filled with soft material, often has an attractive cover, and is used especially on chairs for sitting or leaning on.
• Duvet: A quilt, often with a removable cover; comforter.
• Wardrobe: A tall cupboard in which you hang your clothes.

Room Atmosphere

• Dimly-lit: Describing the way a room is lit when there's only a small amount of light.
• Restful: Used to describe something that produces a feeling of being calm and relaxed.

Social Dynamics

• Alter: To change, or to make someone or something change.
• Compromise: The act of agreeing to something that is not exactly what you want in

Properties of Metals

PROPERTIES OF METALS: good electrical, thermal and acoustic conductors; ductile and malleable; tough; they melt at high temperatures, expand when the temperature rises and contract when it cools; some are magnetic; rust when they come into contact with air and oxygen (not all); can be recycled and reused, some are toxic for the environment.

Ferrous Metals

FERROUS METALS: main component is iron.

PURE IRON: greyish white colour, good magnetic properties. Disadvantages: only melts at high temperature, difficult to machine, fragile and brittle. Uses: rarely used, used in electronics and electrical components. CAST IRON: very hard and resistant. Uses: machine parts, casing for engines, stands for machines, pistons, street lamps,... Continue reading "Properties of Metals and Ferrous vs. Non-Ferrous Metals" »

Function Definition

A function definition in C++ consists of the statements that constitute a function. It includes:

• Name: The identifier of the function.
• Parameter List: Variables enclosed in parentheses that hold values passed to the function.
• Body: Statements within curly braces that perform the function's task.
• Return Type: The data type of the value the function returns (e.g., int, double, void if no value is returned).

Function Header

The function header declares the function. It consists of:

• Return Type
• Name
• Parameter List

For example: void evenOrOdd(int num). Note that there is no semicolon at the end of the header.

Function Return Type

• If a function returns a value, the return type must be specified (e.g., int main()).
• If a function doesn't return

What is Injection Molding?

Injection molding is a manufacturing process for producing parts in large volumes. It is most typically used in mass-production processes where the same part is being created thousands or even millions of times in succession.

Injection Molding Machine

Why Use Injection Molding?

The principal advantage of injection molding is the ability to scale production en masse. Once the initial costs have been paid, the price per unit during injection molded manufacturing is extremely low. The price also tends to drop drastically as more parts are produced. Other advantages include the following:

• Molding is very repeatable. That is, the second part you produce is going to be practically identical to the first one. This is a wonderful

Circulator

A nonreciprocal device, means transfer function cannot be calculated inverse (output to input). The characteristic of this device depends on which direction the applied signal. It is based on magnetic ferrite and uses a ferrite core.

MW Semiconductor Devices

• Diodes: can be used for detecting MW signals. (Until the 1960s).
• -Schottky pin diodes are passive. Varactor, tunnel are active diodes. Gun impatt, trapatt. You can't use diodes with wires because this wire becomes inductive and stops MW signal. Connect diode chips with wire bonds (without connectors.)
• Schottky barrier diode: there are no minority carriers, so there is no delay (only majority). The operation speed is high, so it can be used in MW applications as a detector.

Cutoff Frequency

Home Automation and Telecommunication

Home Automation

Home Automation refers to the use of computer and information technology to control a home. This includes various aspects such as:

• HVAC (Heating, Ventilation, and Air Conditioning): Controls the temperature and air quality in your home.
• Lighting: Allows you to control lights remotely and automate lighting schedules.
• Intercom: Enables communication within the home or with visitors at the door.
• Smart Window: Windows that can be automatically tinted or adjusted for optimal energy efficiency.
• Video Door Phone System: Allows you to see and communicate with visitors at your door remotely.
• Socket: Smart sockets that can be controlled remotely and monitor energy usage.
• TV Set: Integration with smart TVs