Circuit Symbols for Diagramming

Circuit Symbols for Diagramming

When creating a circuit diagram, it’s important to understand how common electrical engineering symbols are used and what they mean. Check out our guide to circuit symbols in Lucidchart to get a head start.

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Common circuit diagram icons

Circuit diagrams can be created with thousands of possible icons and symbols. Lucidchart’s circuit diagram library is schematic and includes many icons commonly used by engineers. From transistors to logic gates, you’ll find icons that are modeled to international standards. Our icons are grouped into families, outlined below.


ELECTRICAL SYMBOLS

These are the most commonly used symbols in circuit diagramming. Amplifiers (denoted by triangle shapes) increase the output signal in your circuit. Capacitors (parallel lines) store energy in your system, while resistors (zigzag lines) reduce current flow. All electrical engineering students should become familiar with these three shapes, as they are universally used in circuit diagrams. In Lucidchart, simply hover over the shape to see its name. You can also search for a shape (e.g. light bulb) and our high-powered search function will bring up both icons and Google image search results.

Circuit Symbols for Diagramming

POWER SOURCES

Lucidchart provides you with accurate symbols for alternating and direct currents. Our easy-to-use dialogs let you switch the direction of the positive and negative charge icons, as well as the orientation and the voltage label. You can also make your circuit diagram stand out by adding a fill color with just one click.

Circuit Symbols for Diagramming

TRANSISTORS

To beginners, the names of transistors can resemble alphabet soup. Lucidchart provides schematics for three major transistor types: bipolar junction transistors (BJT), junction gate field-effect transistors (JFET), and metal oxide semiconductor field-effect transistors (MOSFET). Each type has its unique advantages and drawbacks. BJTs have high transconductance, whereas MOSFETs excel at low voltages. A useful mnemonic device for remembering which transistors are PNP (positive-negative-positive) and which are NPN (negative-positive-negative) is “not pointing in” for NPN and “pointing in proudly” for PNP.

Circuit Symbols for Diagramming

RELAYS

Relays form switches in your electrical circuit. Our relays are labeled for easy comprehension. They include both the full name, e.g. Single Pole Single Throw, and its abbreviation—in this case, SPST. You can easily rotate a relay, or any other icon in Lucidchart, to fit the parameters of your circuit diagram.

Circuit Symbols for Diagramming

LOGIC GATES

Logic gates perform logical functions (i.e. “and,” “not and,” or “exclusive or”) on one or more inputs to create a single output. Lucidchart has international-style logic gate icons, including an inverter. You can also choose from several types of flip-flops.

Circuit Symbols for Diagramming

VOLTMETERS, CHARGE SYMBOLS, WAVES, AND MORE

Our Miscellaneous library gives you even more options for customization. If you ever made a potato-powered battery for an elementary school science fair, you’re familiar with voltmeters. You can also drag and drop an ammeter, an inverter contact, and an electrical charge symbol onto your canvas.

Circuit Symbols for Diagramming

Lucidchart is perfect for building circuit diagrams. Enjoy an intuitive drag-and-drop editor and a huge array of shapes, all for an affordable price.

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