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Revision as of 04:19, 22 December 2019 by Sbmeirow (talk | contribs) (→Further reading: fix)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)An electronic symbol is a pictogram used to represent various electrical and electronic devices or functions, such as wires, batteries, resistors, and transistors, in a schematic diagram of an electrical or electronic circuit. These symbols are largely standardized internationally today, but may vary from country to country, or engineering discipline, based on traditional conventions.
Standards for symbols
The graphic symbols used for electrical components in circuit diagrams are covered by national and international standards, in particular:
- IEC 60617 (also known as British Standard BS 3939).
- There is also IEC 61131-3 - for ladder-logic symbols.
- JIC JIC (Joint Industrial Council) symbols as approved and adopted by the NMTBA (National Machine Tool Builders Association). They have been extracted from the Appendix of the NMTBA Specification EGPl-1967
- 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. (Based on a slightly modified version of IEC 60617, Withdrawn without replacement with a recommendation to use IEC 60617)
The number of standards leads to confusion and errors. Symbols usage is sometimes unique to engineering disciplines and national or local variations to international standards exist. For example, lighting and power symbols used as part of architectural drawings may be different from symbols for devices used in electronics.
Gallery of common electronic symbols
Symbols shown are typical examples, not a complete list.
Traces
- IEC-style trace junction
- Trace crossing
Grounds
Sources
- Battery, single cell and multi-cell
- Battery, multi-cell
- Voltage source
- Controlled voltage source
- Current source
- Controlled current source
- AC voltage source
Resistors
- (a) resistor, (b) rheostat (variable resistor), and (c) potentiometer (All of them are American style symbols)
- (a) resistor, (b) rheostat (variable resistor), and (c) potentiometer (All of them are IEC style symbols)
- Thermistor or Varistor
Capacitors
- IEC-style capacitor, general symbol
- Capacitor, polarized (American)
- Capacitor, variable
- IEC-style ganged (co-moving) variable capacitors
- Trimmer capacitor
Diodes
- Diode
- Zener diode
- Tunnel diode
- Schottky diode
- Light Emitting Diode (LED)
- Photodiode
- Varicap
- Shockley diode
- Silicon-controlled rectifier (SCR)
- Constant-current diode
Inductors
Transformers
- Transformer with center tap
- Transformer with two secondary windings
- Current Transformer
- Zero-Sequence Current Transformer (ZSCT) (also known as a window-type current transformer)
- Bushing-Type Current Transformer
- Voltage Transformer
Transistors
Unipolar
- N-channel junction gate field-effect transistor (JFET)
- P-channel junction gate field-effect transistor (JFET)
- Metal-Oxide-Semiconductor Field-Effect Transistor
- Enhancement mode, N-channel MOSFET
- Enhancement mode, P-channel MOSFET
Bipolar
- NPN bipolar junction transistor (BJT)
- PNP bipolar junction transistor (BJT)
- NPN darlington
- PNP darlington
Vacuum tubes
- Vacuum tube diode
- Vacuum tube triode
- Vacuum tube tetrode
- Vacuum tube pentode
Switches
- Switch, Single Pole/Single Throw (SPST)
- Switch, Single Pole/Double Throw (SPDT)
- Switch, Double Pole/Double Throw (DPDT)
- Pushbutton, Momentary or Spring-Return, make (IEEE Std 315)
- Pushbutton, Momentary or Spring-Return, break (IEEE Std 315)
- Pushbutton, Momentary or Spring-Return, two circuit (IEEE Std 315)
Relays
- American-style relays, SPST, SPDT, DPST, DPDT
- IEC relay symbol, SPDT
Lamps
- Indicating lamp (IEEE Std 315-1975)
- Incandescent lamp
- Incandescent light bulb (as an indicator)
- Neon lamp
- Light bulb
Current limiters
- IEC Fuse (b), equivalent symbols (a,c) (IEEE Std 315-1975)
- Moulded Case Circuit Breaker (MCCB)
- Fuse: IEC (top) and American (lower two)
Electro-acoustic devices
- IEC-style microphone
- Microphone (IEEE Std 315)
- Buzzer
- Loudspeaker (IEEE Std 315)
Antennas
Miscellaneous devices
- Phone jacks
- Operational amplifier
- Ferrite bead ring (IEEE Std 315)
- Crystal oscillator
- Hall effect sensor
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)
See also
References
- Guidelines for Drawing Schematics
- Circuit Symbols for all Electronic Components. Talking Electronics, 2013. Retrieved 01 Apr 2015.
- Electrical Symbols & Electronic Symbols. RapidTables, 2012. Retrieved 17 April 2016.
Further reading
- How to Read Electronic Circuit Diagrams; 2nd Ed; Brown, Lawrence, Whitson; Tab Books; 214 pages; 1988; ISBN 978-0830628803.
- How to Read Schematic Diagrams; 4th Ed; Donald Herrington; Sams Publishing; 160 pages; 1986; ISBN 978-0672224577. (2nd Ed in 1973)
External links
- IEEE Standard American National Standard Canadian Standard Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters)
- International standard IEC 60617 DB Graphical symbols for diagrams
- Electrical Schematic Symbols
- Collection of Open Source Electrical, Pneumatic, Hydraulic and Electronic Symbols
- Circuit Symbols of Electronic Components
- Electrical & Electronic Drawing Symbols
- Collection of Electrical and Electronic Symbols
- Circuit Schematic Symbols
- Collection of Electrical and Electronic Schematic Symbols