electronic symbol

The graphic symbols used for electrical components in circuit diagrams are covered by national and international standards, in particular:

• IEC 60617 (also known as 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 [https://doi.org/10.1109/IEEESTD.1993.93397 IEEE Std 315-1975]"IEEE Standard American National Standard Canadian Standard Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters)," in IEEE Std 315-1975 (Reaffirmed 1993), vol., no., pp.i-244, 1993, {{doi|10.1109/IEEESTD.1993.93397}}. 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• Australian Standard AS 1102 (based on a slightly modified version of IEC 60617; withdrawn without replacement with a recommendation to use IEC 60617).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 standards do not all agree, and use of unusual (even if standardized) symbols can lead to confusion and errors.Sobering, Tim (April 2008). [https://www.k-state.edu/edl/docs/pubs/technical-resources/Technote8.pdf Guidelines for Drawing Schematics].

Symbols usage is sometimes idiosyncratic 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.

Symbols shown are typical examples, not a complete list.[http://www.talkingelectronics.com/CctSymbols/Circuit_Symbols.html Circuit Symbols for all Electronic Components.] Talking Electronics, 2013. Retrieved 01 Apr 2015.[https://unitconverterhub.com Electrical Symbols & Electronic Symbols.] UnitConvertHub, 2012. Retrieved 17 April 2016.

File:Wire Crossover Symbols for Circuit Diagrams.pngs. The CAD symbol for insulated crossing wires is the same as the older, non-CAD symbol for non-insulated crossing wires. To avoid confusion, the wire "jump" (semi-circle) symbol for insulated wires in non-CAD schematics is recommended (as opposed to using the CAD-style symbol for no connection), so as to avoid confusion with the original, older style symbol, which means the exact opposite. The newer, recommended style for 4-way wire connections in both CAD and non-CAD schematics is to stagger the joining wires into T-junctions.

The large dot signifies an electrical connection.]]{{clear left}}

The shorthand for ground is GND. Optionally, the triangle in the middle symbol may be filled in.

File:IEEE 315 Transmission Path Symbols (75).svg|General ground (IEC{{nbh}}style)

File:IEEE 315 Transmission Path Symbols (80).svg|Signal/low-noise ground (the asterisk is not part of the symbol)

File:IEEE 315 Transmission Path Symbols (78).svg|Chassis/Earth ground (IEC{{nbh}}style)

Voltage text should be placed next to each battery symbol, such as "3V".

File:IEEE 315 Fundamental Items Symbols (90).svg|Battery, single-cell

File:IEEE 315 Fundamental Items Symbols (92).svg|Battery, multi-cell

File:IEEE 315-1975 (1993) 8.7.3.svg|Solar (photovoltaic) cell

File:Voltage source 2.svg|DC voltage source

File:Controlled Current source.svg|Controlled DC voltage source

File:Current source.svg|Current source

File:Controlled Current source 2.svg|Controlled current source

File:AC voltage source.svg|AC voltage source

{{See also|Resistor}}

It is very common for potentiometer and rheostat symbols to be used for many types of variable resistors and trimmers.

File:Resistor, Rheostat (variable resistor), and Potentiometer symbols.svg|ANSI{{nbh}}style: (a) Resistor, (b) Rheostat, (c) Potentiometer / Trimmer

File:IEC resistors.svg|IEC{{nbh}}style: (a) Resistor, (b) Rheostat, (c) Potentiometer / Trimmer

File:IEEE 315-1975 (1993) 2.1.13.svg|Photoresistor (ANSI)

File:IEEE 315-1975 (1993) 2.1.12.1.2.svg|{{ubl|Thermistor (ANSI).{{cite journal |title=Standards for Resistor Symbols |publisher=EETech Media |journal=EePower |url=https://eepower.com/resistor-guide/resistor-standards-and-codes/resistor-symbols/ |accessdate=September 13, 2021}}|Use -t for NTC symbol.|Use +t for PTC symbol.}}

File:IEEE 315-1975 (1993) 2.1.6.a.svg|Varistor (ANSI)

{{See also|Capacitor}}

File:IEEE 315 Fundamental Items Symbols (32).svg|General capacitor (IEC{{nbh}}style); sometimes drawn with one plate curved

File:IEEE 315 Fundamental Items Symbols (36).svg|Polarized capacitor (American{{nbh}}style), such as electrolytic and tantalum capacitors

File:IEEE 315 Fundamental Items Symbols (38).svg|Variable capacitor

File:IEEE 315 Fundamental Items Symbols (41).svg|Ganged (co{{nbh}}moving) variable capacitors (IEC{{nbh}}style)

File:Trimmer capacitor symbol GOST.svg|Trimmer variable capacitor

{{See also|Diode}}

Optionally, the triangle in these symbols may be filled in, or a line may be drawn through the triangle (less desirable). The words anode and cathode aren't part of the diode symbols. For instructional purposes, sometimes two letters (A/C or A/K) are placed next to diode symbols similar to how the letters C/B/E or D/G/S are placed next to transistor symbols. "K" is often used instead of "C", because the origin of the word cathode is kathodos, and to avoid confusion with "C" for capacitors in silkscreen of printed circuit boards. Voltage text should be placed next to each zener and TVS diode symbol, such as "5.1V".

File:Diode symbol.svg | Diode (rectifier)

File:Schottky diode symbol.svg | Schottky diode

File:Zener diode symbol-2.svg | Zener diode

File:TVS diode symbols.svg | TVS (Transient Voltage Suppression) diode. Top is unidirectional, bottom is bidirectional.

File:LED symbol.svg | LED (Light Emitting Diode)

File:Photodiode symbol.svg | Photodiode

File:Tunnel diode symbol.svg | Tunnel diode

File:Varicap symbol.svg | Varicap

File:Shockley diode.svg | Shockley diode

File:SCR symbol.svg | SCR (Silicon Controlled Rectifier)

File:Diac-schematic-symbol.png | Diac (may be a varistor in older schematics)

File:Constant Regulating Diode.png | Constant-current diode

File:Symbol Opto-Isulator.svg | Opto-isolator: internal LED (left) and photo transistor (right)

{{See also|Diode bridge|l1=Bridge rectifier}}

There are many ways to draw a single-phase bridge rectifier symbol. Some simplified symbols don't show the internal diodes.

File:Bridge Rectifier.svg|Bridge rectifier

File:УГО диодного моста.svg|Bridge rectifier

File:4 diodes bridge rectifier.jpg|Bridge rectifier

File:Bridge Rectifier for single-phase alternating current (symbolic diagram).png|Bridge rectifier

File:3 fase bridge rectifier.jpg|Three-phase bridge rectifier

{{See also|Inductor}}

An inductor can be drawn either as a series of loops, or series of half-circles.

File:Coil illustration.svg|Inductor symbol (series of loops)

File:IEC Inductor.svg|Air-core inductor (IEC{{nbh}}style)

File:IEC Inductor with magnetic core.svg|Magnetic-core inductor (IEEE{{nbh}}style)

File:IEC Tapped inductor.svg|Tapped inductor (IEC{{nbh}}style)

File:Ferrite bead ring.svg|Ferrite bead (IEEE{{nbh}}style)

File:Reguleeritav pool.jpg|Variable inductor

File:Seadepool.jpg|Trimmer variable inductor

{{See also|Transformer}}

Voltage text should be placed on both sides of power transformers, such as 120V (input side) and 6.3V (output side).

File:Transformer Iron Core.svg|Transformer

File:Transformer center tap.svg|Transformer with center tap on secondary winding (right side)

File:Transformer two secondary windings.svg|Transformer with two secondary windings (right side)

File:Basic Current Transformer Symbol.svg|Current transformer

File:Zero Sequence Current Transformer Symbol.svg|Zero-sequence current transformer (ZSCT) (also known as a window-type current transformer)

File:Bushing Type Current Transformer Symbol.svg|Bushing-type current transformer

File:Voltage Transformer.svg|Voltage transformer

{{See also|Transistor}}

Optionally, transistor symbols may include a circle.{{Cite book|url=https://www.julesbartow.com/Construction/ANSI%20Y32.2-1975.pdf|title=ANSI Y32.2-1975|chapter=A4.11 Envelope or Enclosure|quote=The envelope or enclosure symbol may be omitted from a symbol referencing this paragraph, where confusion would not result|access-date=2020-12-29|archive-date=2022-10-09|archive-url=https://ghostarchive.org/archive/20221009/https://www.julesbartow.com/Construction/ANSI%20Y32.2-1975.pdf|url-status=dead}} Note: The pin letters B/C/E and G/D/S aren't part of the transistor symbols.

{{See also|Bipolar junction transistor}}

File:IEEE 315-1975 (1993) 8.6.2.svg|NPN bipolar junction transistor (BJT)

File:IEEE 315-1975 (1993) 8.6.1.svg|PNP bipolar junction transistor (BJT)

File:IEEE 315-1975 (1993) 8.6.17.svg|NPN Darlington transistor

File:PNP darlington.svg|PNP Darlington transistor

File:PhototransistorSymbol.png|NPN Phototransistor

{{See also|Field-effect transistor}}

File:IEEE 315-1975 (1993) 8.6.10.1.b.svg|N-channel junction gate field-effect transistor (JFET)

File:IEEE 315-1975 (1993) 8.6.11.1.b.svg|P-channel junction gate field-effect transistor (JFET)

File:IGFET N-Ch Enh Labelled simplified.svg|Metal–oxide–semiconductor field-effect transistor (MOSFET)

File:Enh N channel Mosfet.svg|Enhancement mode, N{{nbh}}channel MOSFET

File:Enh P channel Mosfet 2.svg|Enhancement mode, P{{nbh}}channel MOSFET

{{See also|Vacuum tube}}

File:Dioda symbol.svg|Vacuum tube diode

File:Trioda symbol.svg|Vacuum tube triode

File:Vacuum Tube Tetrode.svg|Vacuum tube tetrode
(pin letters not part of symbol)

File:Pentoda symbol.svg|Vacuum tube pentode

{{See also|Switch}}

For multiple pole switches, a dotted or dashed line can be included to indicate two or more switch at the same time (see DPST and DPDT examples below).

File:Poussoir-NO-symbol.png|Pushbutton, normally open, push-to-make (horizontal line on top)

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (57).svg|Pushbutton, normally open, push-to-make (IEEE-style)

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (58).svg|Pushbutton, normally closed, push-to-break (IEEE-style)

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (59).svg|Pushbutton, normally closed, two circuits (IEEE-style)

File:SPST-Switch.svg|Switch, 1P1T, SPST (single-pole single-throw)

File:DPST-symbol.svg|Switch, 2P1T, DPST (double-pole single-throw)

File:SPDT-Switch.svg|Switch, 1P2T, SPDT (single-pole double-throw)

File:DPDT-symbol.svg|Switch, 2P2T, DPDT (double-pole double-throw)

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (84).svg|Rotary switch, 1P3T,
break-before-make, nonshorting style

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (86).svg|Rotary switch, 1P4T,
break-before-make, nonshorting style

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (88).svg|Rotary switch, 1P4T,
make-before-break, shorting style

File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (89).svg|Slide switch, 1P4T,
make-before-break, shorting style

File:Reed switch symbol.svg|Reed switch, normally open

{{See also|Relay}}

Relays symbols are a combination of an inductor symbol and switch symbol.

Note: The pin letters in these symbols aren't part of the standard relay symbol.

File:Relay symbols.svg|SPST, SPDT, DPST, DPDT relays (American{{nbh}}style)

File:Relay-IEC.svg|SPDT relay (IEC{{nbh}}style)

LED is located in the diode section.

File:Neon lamp schematics.svg|Neon lamp

File:Indicating lamp.svg|Indicating lamp (IEEE{{nbh}}style)

File:Lamp symbol, old.svg|Incandescent lamp

File:Lamp symbol.svg|Indicatory incandescent light bulb

File:Light bulb 3.svg|Light bulb

File:Fuces.svg|IEC fuse (b), equivalent symbols (a, c) {{awrap|(IEEE Std 315-1975)}}

File:Molded Case Circuit Breaker.svg|Molded-case circuit breaker (MCCB)

File:Fuse-basic-symbols.svg|Fuse: IEC (top) and American (lower two)

TVS and Zener diodes are located in the diode section.

File:Symbol Surge Arrester.svg|Gas-discharge tubes (GDT) for ESD discharge

File:Symbol Spark gap.svg|Spark gap for ESD discharge

Speaker symbols sometimes include an internal inductor symbol. Impedance text should be placed next to each speaker symbol, such as "8 ohms".

File:IEEE Loudspeaker.svg|Loudspeaker
(IEEE-style)

File:Buzzer-IEC-Symbol.svg|Buzzer
(IEC-style)

File:IEEE MIC.svg|Microphone
(IEEE-style)

File:IEC MIC.svg|Microphone
(IEC-style)

{{See also|Antenna (radio)}}

File:IEEE 315 Fundamental Items Symbols (55).svg|General antenna
(IEC-style)

File:IEEE 315 Fundamental Items Symbols (58).svg|Dipole antenna
(IEC-style)

File:IEEE 315 Fundamental Items Symbols (61).svg|Loop antenna
(IEC-style)

File:IEEE 315 Fundamental Items Symbols (60).svg|Loop antenna
(IEEE-style)

{{See also|Electrical cable}}

File:IEEE 315 Transmission Path Symbols (26).svg|Cable, Shielded 1 conductor

File:IEEE 315 Transmission Path Symbols (30).svg|Cable, 2 conductor

File:IEEE 315 Transmission Path Symbols (29).svg|Cable, Shielded 2 conductor with shield connected to ground

File:IEEE 315 Transmission Path Symbols (31).svg|Cable, 5 conductor

File:IEEE 315 Transmission Path Symbols (27).svg|Cable, Shielded 5 conductor

{{See also|Electrical connector}}

There are numerous connector symbol variations.

File:Phone Jack Symbols.svg | Phone connectors. "A" is TS, "B" is TRS, "D" is TRS with two switches.

File:UEXTPINS.svg | 5x2 shrouded header with notch key and pin names for Olimex UEXT.

File:DE-9.svg | DE-9 D-subminiature with host side pin names for RS-232 serial port.

{{See also|Integrated circuit}}

{{See also|Logic gate#Symbols|l1=Logic gates}}

For the symbols below: A and B are inputs, Q is output. Note: These letters are not part of the symbols.

There are variations of these logic gate symbols. Depending on the IC, the two-input gates below may have: 1) two or more inputs; 2) infrequently some have a second inverted {{overline|Q}} output too.

File:Buffer ANSI Labelled.svg|Buffer

File:NOT ANSI Labelled.svg|Inverter (NOT)

File:AND ANSI Labelled.svg|AND

File:NAND ANSI Labelled.svg|NAND

File:OR ANSI Labelled.svg|OR

File:NOR ANSI Labelled.svg|NOR

File:XOR ANSI Labelled.svg|XOR

File:XNOR ANSI Labelled.svg|XNOR

The above logic symbols may have additional I/O variations too: 1) schmitt trigger inputs, 2) tri-state outputs, 3) open-collector or open-drain outputs (not shown).

File:Schmitt trigger symbol.svg|Buffer gate with schmitt trigger input

File:Tristate buffer.svg|Buffer gate with tri-state output control.
(B is the tri-state control)

{{See also|Flip-flop (electronics)|l1=Flip-flops}}

For the symbols below: Q is output, {{overline|Q}} is inverted output, E is enable input, internal triangle shape is clock input, S is Set, R is Reset (some datasheets use clear (CLR) instead of reset along the bottom).

There are variations of these flip-flop symbols. Depending on the IC, a flip-flop may have: 1) one or both outputs (Q only, {{overline|Q}} only, both Q & {{overline|Q}}); 2) one or both forced inputs along top & bottom (R only, S only, both R & S); 3) some inputs may be inverted.

File:Inverted SR Flip-flop.svg|Simple SR flip-flop (inverted S & R inputs)

File:Gated SR flip-flop Symbol.svg|Gated SR flip-flop

File:Transparent Latch Symbol.svg|Gated D flip-flop (Transparent Latch)

File:D-Type Flip-flop.svg|Clocked D flip-flop
(Set & Reset inputs)

File:JK Flip-flop (Simple) Symbol.svg|Clocked JK flip-flop

File:T-Type Flip-flop.svg|Clocked T flip-flop

Note: The outside text isn't part of these symbols.

File:Op-amp symbol.svg|Operational amplifier (opamp)

File:Comparator symbol.svg|Comparator

{{See also|Electronic oscillator}}

Frequency text should be placed next to each oscillator symbol, such as "16MHz".

File:IEEE 315 Fundamental Items Symbols (113).svg|Crystal oscillator (IEEE{{nbh}}style)

File:Schaltsymbol-Keramikresonator.svg|Ceramic resonator (3 pins)

File:Common Hall Sensor Symbol.png|Hall-effect sensor

The shape of some electronic symbols have changed over time. The following historical electronic symbols can be found in old electronic books / magazines / schematics, and now considered obsolete.

All of the following are obsolete capacitor symbols.

File:Polarized capacitor symbol 5.png|Obsolete capacitor (very old style)

File:Capacitor old.svg|Obsolete capacitor

File:Capacitor old with polarity.svg|Obsolete capacitor

File:Polarized capacitor symbol 3.svg|Obsolete capacitor

File:Elco's.jpg|Obsolete capacitor

{{Portal|Electronics}}

• Circuit diagram
• Reference designator
• Symbols for appliance classes

{{Reflist}}

;Standards

• IEC [http://std.iec.ch/iec60617 60617 : Graphical Symbols for Diagrams]; 2012.
• IEEE [https://ieeexplore.ieee.org/document/985670/ 315 : Graphic Symbols for Electrical and Electronics Diagrams (including Reference Designation Letters)]; 1975.
• U.S. DoD MIL-STD-806B : Graphical Symbols for Logic Diagrams; 1962. [https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35975 (RevB in 1962)]

;Books

• [https://www.amazon.com/dp/1260031101/ Beginner's Guide to Reading Schematics]; 4th Ed; Stan Gibilisco; McGraw-Hill, 224 pages; 2018; {{ISBN|978-1260031119}}.
• [https://www.amazon.com/dp/1258076764/ How to Read Schematic Diagrams]; 5th Ed; Donald Herrington; Literary Licensing; 130 pages; 2011; {{ISBN|978-0672224577}}. [https://archive.org/details/howtoreadschemat00herr/ (4ed in 1986)][https://web.archive.org/web/20210309184547/https://worldradiohistory.com/BOOKSHELF-ARH/Sams-Books/How%20To%20Read%20Schematic%20Diagrams%20-%20Donald%20E.%20Herrington.pdf (2ed in 1967)]
• [https://www.amazon.com/dp/0830604804/ How to Read Electronic Circuit Diagrams]; 2nd Ed; Robert Brown, Paul Lawrence, James Whitson; Tab Books; 214 pages; 1988; {{ISBN|978-0830628803}}. [https://archive.org/details/howtoreadelectro00robe_0 (2ed in 1988)]
• [https://www.amazon.com/dp/B002806PKO/ Engineer's Mini-Notebook : Schematic Symbols, Device Packages, Design and Testing]; 1st Ed; Forrest M. Mims III; Radio Shack; 48 pages; 1988. [https://web.archive.org/web/20210308225202/https://worldradiohistory.com/Archive-Company-Publications/Radio-Shack/Engineer's%20Mini-Notebook%20-%20Schematic%20Symbols,%20Device%20Packages%20Design%20and%20Testing.pdf (1ed in 1988)]

{{Commons category|Electrical symbols}}

{{Electronic components}}

{{DEFAULTSORT:Electronic Symbol}}

Category:Electronic engineering

Category:Pictograms