Understanding Basic Electrical Concepts
Electricity Basics
Introduction to Electricity
Electricity is the movement of electrons through a conductor, such as a wire. This movement requires an energy source, like a generator.
Types of Current
Direct Current (DC)
In direct current, electrons flow continuously in one direction, from the negative to the positive terminal of a power source. Examples include batteries and flashlights.
Alternating Current (AC)
In alternating current, the flow of electrons changes direction periodically. This is the type of current used in most household appliances.
Circuit Elements
- Electric Generator: Produces electricity from another energy source.
- Conductors: Materials that allow electricity to flow easily, such as wires and cables.
- Receivers/Loads: Devices that transform electrical energy into other forms of energy, such as light (lamps) or motion (motors).
- Switching/Control Elements: Devices that control the flow of current, such as switches and buttons.
- Protection Elements: Devices that protect circuits and users from overloads and other electrical hazards, such as fuses and circuit breakers.
Types of Connections
Series Connection
In a series connection, components are connected end-to-end, so the current flows through each component in turn.
Parallel Connection
In a parallel connection, components share the same two connection points, so the current divides among them.
Electrical Concepts
Resistance
Resistance is the opposition to the flow of current. It is measured in ohms (Ω). Resistance is calculated using the formula: R = ρL/S, where ρ is resistivity, L is length, and S is cross-sectional area.
Voltage
Voltage, also known as potential difference, is the force that drives the flow of current. It is measured in volts (V).
Current
Current is the rate of flow of electric charge. It is measured in amperes (A).
Ohm’s Law
Ohm’s Law states that the current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance: V = IR, R = V/I, I = V/R.
Electric Power
Electric power is the rate at which electrical energy is consumed or produced. It is measured in watts (W) or kilowatts (kW): P = VI.
Electrical Energy
Electrical energy is the total amount of electrical energy consumed or produced over time. It is measured in watt-hours (Wh) or kilowatt-hours (kWh): E = Pt.
Thermistors
Thermistors are devices whose resistance changes with temperature.
NTC (Negative Temperature Coefficient)
NTC thermistors have resistance that decreases with increasing temperature.
PTC (Positive Temperature Coefficient)
PTC thermistors have resistance that increases with increasing temperature.
Diodes
LED (Light-Emitting Diode)
LEDs are diodes that emit light when current flows through them in the forward direction.
Zener Diode
Zener diodes are used to regulate voltage in a circuit.