How to Identify Circuit Symbols

Electronic symbol


Common circuit diagram symbols (US symbols)

An electronic symbol is a pictogram used to represent various electrical and electronic devices (such as wires, batteries, resistors, and transistors) in a schematic diagram of an electrical or electronic circuit. These symbols can (because of remaining traditions) vary from country to country, but are today to a large extent internationally standardized. Some symbols represent components (such as vacuum tubes) which ceased to be used routinely as newer technologies were introduced.

Contents


  • 1Standards for symbols
  • 2Gallery of common electronic symbols
    • 2.1Traces
    • 2.2Circuit Return
    • 2.3Sources
    • 2.4Resistors
    • 2.5Capacitors
    • 2.6Inductors
    • 2.7Transistors
      • 2.7.1Unipolar
      • 2.7.2Bipolar
    • 2.8Diodes
    • 2.9Antennas
    • 2.10Vacuum tubes
    • 2.11Switches
    • 2.12Relays
    • 2.13Lamps
    • 2.14Current Limiters
    • 2.15Transformers
    • 2.16Acoustic Devices
    • 2.17Miscellaneous
  • 3Gallery of historical electronic symbols
    • 3.1Capacitors (historical)
  • 4References

1 Standards for symbols


There are several national and international standards for graphical symbols in circuit diagrams, in particular:

  • IEC 60617 (also known as British Standard BS 3939).
  • ANSI Y32.2-1975 (also known as IEEE Std 315-1975 or CSA Z99-1975)
  • IEEE Std 91/91a: graphic symbols for logic functions (used in digital electronics). It is referenced in ANSI Y32.2/IEEE Std 315.
  • Australian Standard AS 1102.

Different symbols may be used depending on the discipline using the drawing. For example, lighting and power symbols used as part of architectural drawings may be different from symbols for devices used in electronics. National and local variations to international standards also exist.

2 Gallery of common electronic symbols


Symbols shown are typical examples, not a complete list.

2.1 Traces

 

2.2 Circuit Return

Sources

Resistors 

Capacitors 

Inductors[edit]

Transistors 

Unipolar 

Bipolar[edit]

Diodes[edit]

Antennas 

Vacuum tubes 

Switches 

Relays[edit]

Lamps[edit]

Current Limiters 

Transformers 

Acoustic Devices 

Miscellaneous 

Gallery of historical electronic symbols 

The shape of electronic symbols have changed over time. Some symbols were more prevalent in some countries. The following are historic electronic symbols that might be found in old electronic books and schematics.

Capacitors (historical) 

 

References 

  1.   Circuit Symbols for all Electronic Components. Talking Electronics, 2013. Retrieved 01 Apr 2015.
  2.   Electrical Symbols & Electronic Symbols. RapidTables, 2012. Retrieved 17 April 2016.

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