{{short description|Pictogram used to represent various electrical and electronic devices or functions}} [[Image:Circuit elements.svg|class=skin-invert-image|right|thumbnail|400px|Common circuit diagram symbols (US ANSI symbols)]] 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 60617:2025 (also known as BS 3939) - current international standard for electronic symbols. * [https://doi.org/10.1109/IEEESTD.1993.93397 IEEE 315-1975]<ref>"IEEE Standard American National Standard Canadian Standard Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters)," in IEEE 315-1975 (Reaffirmed 1993), vol., no., pp.i-244, 1993, {{doi|10.1109/IEEESTD.1993.93397}}.</ref> (also known as ANSI Y32.2-1975 or CSA Z99-1975) - reaffirmed in 1993, inactivated without replacement as of November 7, 2019. * IEEE 91/91a - graphic symbols for logic functions (used in digital electronics). It is referenced in IEEE 315 / ANSI Y32.2. * Australian Standard AS 1102 (based on a slightly modified version of IEC 60617) - withdrawn without replacement with a recommendation to use IEC 60617. * DIN 40700 and 40900 (Germany) - inactivated. * 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. * IEC 61131-3:2025 for ladder-logic symbols.
The standards do not all agree, and use of unusual (even if standardized) symbols can lead to confusion and errors.<ref name=Sobering>Sobering, Tim (April 2008). [https://www.k-state.edu/edl/docs/pubs/technical-resources/Technote8.pdf ''Guidelines for Drawing Schematics''] {{Webarchive|url=https://web.archive.org/web/20201128084359/https://www.k-state.edu/edl/docs/pubs/technical-resources/Technote8.pdf |date=2020-11-28 }}.</ref> 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.
==Common electronic symbols== Symbols shown are typical examples, not a complete list.<ref>[http://www.talkingelectronics.com/CctSymbols/Circuit_Symbols.html Circuit Symbols for all Electronic Components.] Talking Electronics, 2013. Retrieved 01 Apr 2015.</ref><ref>[https://unitconverterhub.com Electrical Symbols & Electronic Symbols.] UnitConvertHub, 2012. Retrieved 17 April 2016.</ref>
===Traces=== [[File:Wire Crossover Symbols for Circuit Diagrams.png|class=skin-invert-image|500px|thumb|left|'''Wire crossover symbols for circuit diagrams.''' 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}}
===Grounds=== The shorthand for ground is GND. Optionally, the triangle in the middle symbol may be filled in. <gallery class="skin-invert-image"> 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) <!-- TODO: need to remove asterisk from symbol --> File:IEEE 315 Transmission Path Symbols (78).svg|Chassis/Earth ground (IEC{{nbh}}style) </gallery>
===Sources=== Voltage text should be placed next to each battery symbol too, such as "3V". <gallery class="skin-invert-image"> File:IEEE 315 Fundamental Items Symbols (90).svg|Battery, single-cell File:IEEE 315 Fundamental Items Symbols (92).svg|Battery, multi-cell <!-- TODO: need to add "+" and "-" next to symbol --> File:IEEE 315-1975 (1993) 8.7.3.svg|Solar (photovoltaic) cell <!-- TODO: need to add "+" and "-" next to symbol --> </gallery> <gallery widths="60px" heights="60px" class="skin-invert-image"> 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 </gallery>
===Resistors=== {{See also|Resistor}} It is very common for potentiometer and rheostat symbols to be used for many types of variable resistors and trimmers. <gallery widths="200" heights="80" class="skin-invert-image"> 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 </gallery> <gallery class="skin-invert-image"> 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).<ref>{{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}}</ref>|Use -t for NTC symbol.|Use +t for PTC symbol.}} File:IEEE 315-1975 (1993) 2.1.6.a.svg|Varistor (ANSI) </gallery>
===Capacitors=== {{See also|Capacitor}} <gallery class="skin-invert-image"> File:IEEE 315 Fundamental Items Symbols (32).svg|Capacitor<br/>(IEC 60617 style) File:IEEE 315 Fundamental Items Symbols (35).svg|Polarized capacitor<br/>(IEC 60617 style) File:IEEE 315 Fundamental Items Symbols (36).svg|Polarized capacitor (old alternate IEEE 315 style) File:IEEE 315 Fundamental Items Symbols (38).svg|Variable capacitor<br/>(IEC 60617 style) File:IEEE 315 Fundamental Items Symbols (41).svg|Ganged (co{{nbh}}moving) variable capacitors<br/>(IEC style) File:Trimmer capacitor symbol GOST.svg|Trimmer variable capacitor </gallery>
===Diodes=== {{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 are not part of the diode symbols. For instructional purposes, sometimes one or 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 too, such as "5.1V".
<gallery class="skin-invert-image"> 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.<!-- NOTE: User:Sbmeirow fixed this symbol on Jan 18, 2025" --> 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) <!-- TODO: need to remove line through middle of LED diode --> </gallery>
====Bridge rectifiers==== {{See also|Diode bridge|l1=Bridge rectifier}} There are many ways to draw a single-phase bridge rectifier symbol. Some simplified symbols do not show the internal diodes. <gallery class="skin-invert-image"> File:Bridge Rectifier.svg|Bridge rectifier <!-- TODO: need to add four short lines, similar to other symbols --> 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 </gallery>
===Inductors=== {{See also|Inductor}} An inductor can be drawn either as a series of loops, or series of half-circles. <gallery class="skin-invert-image"> 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 </gallery>
===Transformers=== {{See also|Transformer}} Voltage text should be placed on both sides of power transformers, such as 120V (input side) and 6.3V (output side). <gallery class="skin-invert-image"> 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 </gallery>
===Transistors=== {{See also|Transistor}} Optionally, transistor symbols may include a circle.<ref>{{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}}</ref> Note: The pin letters B/C/E and G/D/S aren't part of the transistor symbols.
====Bipolar==== {{See also|Bipolar junction transistor}} <gallery class="skin-invert-image"> File:IEEE 315-1975 (1993) 8.6.2.svg|NPN bipolar junction transistor (BJT) <!-- TODO: need to flip and rotate to make BASE be on left side, and EMITTER be on bottom side --> File:IEEE 315-1975 (1993) 8.6.1.svg|PNP bipolar junction transistor (BJT) <!-- TODO: need to rotate clockwise to make BASE be on the left side --> File:IEEE 315-1975 (1993) 8.6.17.svg|NPN Darlington transistor File:PNP darlington.svg|PNP Darlington transistor File:PhototransistorSymbol.png|NPN Phototransistor </gallery>
====Unipolar==== {{See also|Field-effect transistor}} <gallery class="skin-invert-image"> 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 </gallery>
===Vacuum tubes=== {{See also|Vacuum tube}} <gallery class="skin-invert-image"> File:Dioda symbol.svg|Vacuum tube diode File:Trioda symbol.svg|Vacuum tube triode File:Vacuum Tube Tetrode.svg|Vacuum tube tetrode<br/>(pin letters not part of symbol) File:Pentoda symbol.svg|Vacuum tube pentode </gallery>
===Switches=== {{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).
<gallery class="skin-invert-image"> 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) </gallery> <gallery class="skin-invert-image"> 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) </gallery> <gallery class="skin-invert-image"> File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (85).svg|Slide switch, 1P3T,<br/>break-before-make, nonshorting style File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (87).svg|Slide switch, 1P4T,<br/>break-before-make, nonshorting style File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (89).svg|Slide switch, 1P4T,<br/>make-before-break, shorting style </gallery> <gallery class="skin-invert-image"> File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (84).svg|Rotary switch, 1P3T,<br/>break-before-make, nonshorting style File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (86).svg|Rotary switch, 1P4T,<br/>break-before-make, nonshorting style File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (88).svg|Rotary switch, 1P4T,<br/>make-before-break, shorting style </gallery> <gallery class="skin-invert-image"> File:Reed switch symbol.svg|Reed switch, normally open </gallery>
===Relays=== {{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. <gallery class="skin-invert-image"> File:Relay symbols.svg|SPST, SPDT, DPST, DPDT relays (American{{nbh}}style) File:Relay-IEC.svg|SPDT relay (IEC{{nbh}}style) </gallery>
===Lamps=== LED is located in the diode section. <gallery class="skin-invert-image"> 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 </gallery>
===Current limiters=== <gallery class="skin-invert-image"> File:Fuces.svg|Fuse: (b) IEC, (a,c) IEEE/ANSI 315-1975 File:Molded Case Circuit Breaker.svg|Molded-case circuit breaker (MCCB) </gallery>
===Voltage limiters=== TVS and Zener diodes are located in the diode section. <gallery class="skin-invert-image"> File:Symbol Surge Arrester.svg|Gas-discharge tubes (GDT) for ESD discharge File:Symbol Spark gap.svg|Spark gap for ESD discharge </gallery>
===Electro-acoustic devices=== Speaker symbols sometimes include an internal inductor symbol. Impedance text should be placed next to each speaker symbol, such as "8 ohms". <gallery widths="65px" heights="65px" class="skin-invert-image"> File:IEEE Loudspeaker.svg|Loudspeaker<br/>(IEEE-style) File:Buzzer-IEC-Symbol.svg|Buzzer<br/>(IEC-style) File:IEEE MIC.svg|Microphone<br/>(IEEE-style) File:IEC MIC.svg|Microphone<br/>(IEC-style) </gallery>
===Antennas=== {{See also|Antenna (radio)}} <gallery class="skin-invert-image"> File:IEEE 315 Fundamental Items Symbols (55).svg|General antenna<br/>(IEC-style) File:IEEE 315 Fundamental Items Symbols (58).svg|Dipole antenna<br/>(IEC-style) File:IEEE 315 Fundamental Items Symbols (61).svg|Loop antenna<br/>(IEC-style) File:IEEE 315 Fundamental Items Symbols (60).svg|Loop antenna<br/>(IEEE-style) </gallery>
===Cables=== {{See also|Electrical cable}} <gallery class="skin-invert-image"> 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 </gallery>
===Connectors=== {{See also|Electrical connector}} There are numerous connector symbol variations. <gallery class="skin-invert-image"> 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. </gallery>
===ICs=== {{See also|Integrated circuit}}
====Logic gates==== {{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.
<gallery class="skin-invert-image"> 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 </gallery>
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).
<gallery widths="200" heights="80" class="skin-invert-image"> File:Schmitt trigger symbol.svg|Buffer gate with schmitt trigger input File:Tristate buffer.svg|Buffer gate with tri-state output control.<br/>(B is the tri-state control) </gallery>
====Flip-flops==== {{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.
<gallery class="skin-invert-image"> 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<br/>(Set & Reset inputs) File:JK Flip-flop (Simple) Symbol.svg|Clocked JK flip-flop File:T-Type Flip-flop.svg|Clocked T flip-flop </gallery>
====OpAmps==== Note: The outside text isn't part of these symbols. <gallery class="skin-invert-image"> File:Op-amp symbol.svg|Operational amplifier (opamp) File:Comparator symbol.svg|Comparator </gallery>
====Voltage Regulator==== Note: 3pin linear or LDO voltage regulator symbols typically have three words inside their symbols, such as "In" on left side, "Out" on right side", "Gnd" on bottom (for fixed output parts, such as LM7805) or "Adj" on bottom (for adjustable output parts, such as LM317). <gallery class="skin-invert-image"> File:Voltage-Regulator-IEC-Symbol.svg|3-pin Linear or LDO voltage regulator File:LM7805 with Decoupling Capacitor.svg|Example schematic of<br/>3-pin voltage regulator </gallery>
===Oscillators=== {{See also|Electronic oscillator}} Frequency text should be placed next to each oscillator symbol, such as "16MHz". <gallery class="skin-invert-image"> File:IEEE 315 Fundamental Items Symbols (113).svg|Crystal oscillator (IEEE{{nbh}}style) File:Schaltsymbol-Keramikresonator.svg|Ceramic resonator (3 pins) </gallery>
===Miscellaneous devices=== <gallery class="skin-invert-image"> File:Common Hall Sensor Symbol.png|Hall-effect sensor </gallery>
==Historical electronic symbols== 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.
===Capacitors (historical)=== All of the following are obsolete capacitor symbols. <gallery class="skin-invert-image"> 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 </gallery>
==See also== {{Portal|Electronics}} * Media control symbols * Circuit diagram * Reference designator * Appliance classes which are indicated with symbols
==References== {{Reflist}}
==Further reading== ;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. <small>[https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35975 (RevB in 1962)]</small>
;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}}. <small>[https://archive.org/details/howtoreadschemat00herr/ (4ed in 1986)]</small><small>''[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)]''</small> * [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}}. <small>''[https://archive.org/details/howtoreadelectro00robe_0 (2ed in 1988)]''</small> * [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. <small>''[https://web.archive.org/web/20210308225202/https://worldradiohistory.com/Archive-Company-Publications/Radio-Shack/Engineer%27s%20Mini-Notebook%20-%20Schematic%20Symbols%2C%20Device%20Packages%20Design%20and%20Testing.pdf (1ed in 1988)]''</small>
==External links== {{Commons category|Electrical symbols}}
{{Electronic components}}
{{DEFAULTSORT:Electronic Symbol}} Category:Electronic engineering Category:Pictograms