Basic Electrical Symbols and Their Meanings
The visual and straightforward way to present an electrical circuit should be diagramming it by using basic electrical symbols. You can depict a complex electrical circuit with the standard and simplified electrical symbols. Therefore, anyone who knows of electrical and electronic circuits can read, understand, and build quickly.
Basic Electrical Symbols
Earth electrode is a metal plate or other conducting elements of electricity partially buried in the earth to constitute and provide a reliable conductive path for the fault current to the ground.
Cell is a device containing electrodes immersed in an electrolyte, used for generating current or for electrolysis.
Battery is a container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power.
Source is a part of a field-effect transistor from which carriers flow into the inter-electrode channel.
Ideal source includes ideal voltage source and ideal current source. An ideal source is a theoretical concept of an electrical current or voltage supply (such as a battery) that has no losses and is a perfect voltage or current supply. Ideal sources are used for analytical purposes because they cannot occur in nature.
Resistor is a device that has resistance to the passage of an electric current.
Capacitor is a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator.
Antenna is an electrical device which converts electric power into radio waves, and vice versa.
Some most commonly-used basic electrical symbols in schematic diagrams are shown below:
Let's take a look at how to use the basic electrical symbols to draw a schematic diagram of the circuit and its components.
Example one: There are three D-cells placed in a battery pack to power a circuit containing three light bulbs. The resistor symbol represents each light bulb. The connecting lines are used to connect the symbols. While don't forget to put the switch in the circuit to control the current flow. The final sketch is shown in the following picture.
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Switches and Relays Symbols
The picture below shows switches symbols. Switch 1P, isolator 1P, circuit breaker 1P, SPST, SPDT, DPST, DPDT and more symbols are available in Edraw Max.
Switch is a device for making and breaking the connection in an electric circuit.
Isolator is a mechanical switch that isolates a part of a circuit from the system as when required. Electrical isolators separate a part of the system from rest for safe maintenance works.
SPST is a single-pole, single-throw (SPST) switch.
SPDT is single-pole, double-throw (SPDT) switch.
DPST is double-pole, single-throw(DPDT) switch.
DPDT is a double-pole, double-throw (DPDT) switch.
As you can see from the above pictures, using electrical symbols to draw an electrical circuit diagram is quite easy. To illustrate the method, we will give you another example about using the basic electrical symbols.
Example two: Three D-cells are placed in a battery pack to power a circuit containing three light bulbs. Firstly, quickly figure out which electrical symbol shall be used in the diagram. Then, think about the layout of these symbols. Last but not least, use a connector tool to connect all the electrical symbols.
Using the basic electrical symbols to draw a circuit diagram can show the manners in which the circuit components are placed. With the complete electrical schematic, you can read the picture to know the physical connections and layout of an electric circuit.
Transmission Path Symbols
The picture below shows the transmission path symbols like wire, multi-line bus, straight bus, junction, terminal, test point, label, outware flow, inware flow, etc.
Wire is used to connect the components in a circuit.
Test point is a location within an electronic circuit that is used to either monitor the state of the circuitry or to inject test signals.
Outward flow means flowing outwardly, so inward flow means flowing inwardly.
The basic electrical symbols are used to simplify the drafting and to help people understand the electrical drawing. Electrical symbols are standardized throughout the industry, so it is easy to achieve the ability to interpret the meaning of the symbols. With the standard electrical symbols in Edraw, you can create a circuit diagram that shows the actual layout of the components simply and quickly.