Electronics and Electricity Fundamentals

Electronics and Electricity

Electronics is the science and technology concerned with the study of electrons and their applications in information processing and transmission.

Direct Current (DC)

Direct current (DC) is the flow of electrons in a single, constant direction with consistent voltage and current over time.

Alternating Current (AC)

Alternating current (AC) is a variable current where voltage and current continuously change direction. The most common type of AC used in homes is sinusoidal, meaning it's a periodic electrical signal that repeats at regular intervals.

Transformers

Transformers are used to increase voltage for electricity transmission from power plants and then decrease it for safe household consumption.

Key AC Parameters

• Cycle: The repeating pattern of the signal over time.
• Period (T): The duration of one complete cycle, measured in seconds.
• Frequency (f): The number of cycles per second, measured in Hertz (Hz).
• Instantaneous Value (v, i): The value of the signal at any given moment.
• Maximum Value (Vmax, Imax): The highest value of the signal within a period.
• Root Mean Square (RMS): The equivalent DC value that produces the same power in a load.

Electronic Components

Electronic circuits are made up of various components, which can be classified as:

• Passive Components: These components cannot amplify or generate electrical signals on their own.
• Active Components: These components can generate or amplify electrical signals.

Resistors

Resistors are passive components that impede the flow of electrical current. Their value is measured in ohms (Ω) and is typically indicated by a color code. Key resistor characteristics include ohmic value, tolerance, and power dissipation.

Rheostats and Potentiometers

Rheostats and potentiometers are variable resistors that can be manually adjusted. They are used to control volume, light intensity, motor speed, and other applications.

Nonlinear Resistors

Nonlinear resistors have variable resistance that changes based on factors like light or temperature.

• Light-Dependent Resistor (LDR): A resistor whose resistance changes with the intensity of light.
• Negative Temperature Coefficient (NTC) Resistor: A resistor whose resistance decreases with increasing temperature.