Back to: Basic Technology JSS 1
Welcome to class!
In today’s class, we will be talking about electricity. Enjoy the class!
Basic Electricity
Electricity:
It is the flow of electrons from one place to another. Electrons can flow through any material but do so more easily in some than in others. How easily it flows is called resistance. The resistance of a material is measured in Ohms.
Note to recall:
- AMPS is amount of electricity.
- VOLTS is the Push, not the amount.
- OHMS slow the flow.
- WATTS is how much gets done.
Electric current:
Any movement of electric charge carriers, such as subatomic charged particles (e.g., electrons having negative charge, proton having positive charge), ions (atoms that have lost or gained one or more electrons), or holes (electron deficiencies that may be thought of as positive particles).
In an electric circuit, this charge is often carried by electrons moving through a wire.
There are two types of electric current:
- direct current (DC)
- alternating current (AC).
The electrons in direct current flow in one direction. The current produced by a battery is direct current. The electrons in alternating current flow in one direction, then in the opposite direction—over and over again.
Electrical circuit
An electrical circuit is a path in which electrons from a voltage or current source flow.
The point where those electrons enter an electrical circuit is called the “source” of electrons. The point where the electrons leave an electrical circuit is called the “return” or “earth ground“. The exit point is called the “return” because electrons always end up at the source when they complete the path of an electrical circuit.
Lets us go over some sample electrical symbols and what they represent.
- Ground or Earth:
A ground symbol (IEC symbol 5017) identifies a ground terminal. It can be used for a zero potential reference point from where current is measured. It is also for electrical shock protection. There are a few different ground symbols. The one we’re showing here is “Earth”, but there’s also a Chassis and Digital/Common ground with slight variations to this symbol.
- Resistor:
A resistor reduces the current flow. In a schematic, this is represented with a few zig-zags squiggles. We’re showing the US/Japan version of this symbol (IEEE).
- Switch:
Disconnects the current when open. We’re showing a simple SPST (single-pole single-throw) toggle switch, but there are variations for SPDT, push-button, dip, relay, and more. For a complete list of switch symbols, check out Smart Draw’s electrical symbol library.
- Capacitor:
A capacitor symbol shows two terminals running into plates. The curved plate indicates that the capacitor is polarized. The curved side has a lower voltage. A small plus sign can be added to the straight side indicated the positive pin.
- Fuse:
A fuse protects electrical circuits by stopping the flow of current when the intensity of current exceeds a set value. It does this by melting a special wire.
- Antenna:
Marks a device, rod, or wire designed to capture radio and electromagnetic waves into electrical signals and vice versa.
- Inductor:
An inductor is also called a coil or reactor. The coils store energy in a magnetic field or flux. An inductor symbol looks like a series of looped coils.
- Transformer:
A transformer is two or more coils coupled by magnetic induction. It helps keep the frequency and reduce tension in an AC circuit.
- Motor:
A motor is a device that can transform electric energy into mechanical energy.
- Source:
Represents the power source for your electronics. This symbol represents a direct current (DC). To represent AC, you’d replace the plus and minus sign with a wave.
- Battery:
Batteries are represented on a schematic with a pair of disproportionate, parallel lines. The number of lines indicates the number of series cells in the battery.
In our next class, we will be talking more about Basic Electricity. We hope you enjoyed the class.
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
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