Electrical Symbols & Electronic Symbols
Electrical symbols and electronic circuit symbols are used for drawing schematic diagram. The symbols represent electrical and electronic components.
Table of Electrical Symbols
Symbol
Component name
Meaning
Wire Symbols Electrical Wire Conductor of electrical current
Connected Wires
Connected crossing
Not connected Wires
Wires are not connected
Switch Symbols and Relay Symbols SPST Toggle Switch Disconnects current when open
SPDT Toggle Switch
Selects between two connections
Pushbutton Switch (N.O)
Momentary switch - normally open
Pushbutton Switch (N.C)
Momentary switch - normally closed DIP switch is used for onboard configuration
DIP Switch
SPST Relay Relay open / close connection by an electromagnet SPDT Relay Close connection by jumper insertion on pins. Solder to close connection
Jumper
Solder Bridge Ground Symbols
Earth Ground
Used for zero potential reference and electrical shock protection. Connected to the chassis of the circuit
Chassis Ground
Digital / Common Ground Resistor Symbols Resistor (IEEE) Resistor reduces the current flow. Resistor (IEC)
Potentiometer (IEEE) Adjustable resistor - has 3 terminals. Potentiometer (IEC) Variable Resistor / Rheostat(IEEE) Adjustable resistor - has 2 terminals. Variable Resistor / Rheostat(IEC) Capacitor Symbols Capacitor Capacitor is used to store electric charge. It acts as short circuit with AC and open circuit with DC.
Capacitor
Polarized Capacitor
Electrolytic capacitor
Polarized Capacitor
Electrolytic capacitor
Variable Capacitor Inductor / Coil Symbols Inductor
Adjustable capacitance
Coil / solenoid that generates magnetic field
Iron Core Inductor
Includes iron
Variable Inductor Power Supply Symbols Voltage Source Generates constant voltage
Current Source
Generates constant current.
AC Voltage Source
AC voltage source Electrical voltage is generated by mechanical rotation of the generator Generates constant voltage
Generator
Battery Cell
Battery
Generates constant voltage Generates voltage as a function of voltage or current of other circuit element. Generates current as a function of voltage or current of other circuit element.
Controlled Voltage Source
Controlled Current Source Meter Symbols Voltmeter
Measures voltage. Has very high resistance. Connected in parallel. Measures electric current. Has near zero resistance. Connected serially. Measures resistance
Ammeter
Ohmmeter
Wattmeter Lamp / Light Bulb Symbols Lamp / light bulb
Measures electric power
Generates light when current flows through
Lamp / light bulb
Lamp / light bulb Diode / LED Symbols Diode Diode allows current flow in one direction only (left to right). Allows current flow in one direction, but also can flow in the reverse direction when above breakdown voltage Schottky diode is a diode with low voltage drop Variable capacitance diode
Zener Diode
Schottky Diode
Varactor / Varicap Diode
Tunnel Diode LED emits light when current flows through Photodiode allows current flow when exposed to light
Light Emitting Diode (LED)
Photodiode Transistor Symbols NPN Bipolar Transistor
Allows current flow when high potential at base (middle) Allows current flow when low potential at base (middle) Made from 2 bipolar transistors. Has total gain of the product of each gain. N-channel field effect transistor
PNP Bipolar Transistor
Darlington Transistor
JFET-N Transistor
JFET-P Transistor
P-channel field effect transistor
NMOS Transistor
N-channel MOSFET transistor
PMOS Transistor Misc. Symbols Motor
P-channel MOSFET transistor
Electric motor Change AC voltage from high to low or low to high. Rings when activated
Transformer
Electric bell
Buzzer
Produce buzzing sound
Fuse
Fuse
The fuse disconnects when current above threshold. Used to protect circuit from high currents.
Bus Contains several wires. Usually for data / address.
Bus
Bus Optocoupler isolates onnection to other board Converts electrical signal to sound waves Converts sound waves to electrical signal Amplify input signal Operates with hysteresis to reduce noise. Converts analog signal to digital numbers
Optocoupler / Opto-isolator
Loudspeaker
Microphone
Operational Amplifier
Schmitt Trigger Analog-to-digital converter (ADC)
Digital-to-Analog converter (DAC) Crystal Oscillator Antenna Symbols Antenna / aerial
Converts digital numbers to analog signal Used to generate precise frequency clock signal
Transmits & receives radio waves Antenna / aerial
Dipole Antenna Logic Gates Symbols NOT Gate (Inverter)
Two wires simple antenna
Outputs 1 when input is 0
AND Gate
Outputs 1 when both inputs are 1. Outputs 0 when both inputs are 1. (NOT + AND) Outputs 1 when any input is 1. Outputs 0 when any input is 1. (NOT + OR) Outputs 1 when inputs are different. (Exclusive OR) Stores one bit of data
NAND Gate
OR Gate
NOR Gate
XOR Gate
D Flip-Flop
Multiplexer / Mux 2 to 1 Connects the output to selected input line. Multiplexer / Mux 4 to 1 Connects selected output to the input line.
Demultiplexer / Demux 1 to 4
Electronic Components
Electronic components are parts of electrical & electronic circuits. Each component has typical functionality according to its operational characteristics.
Electrical and electronic components table
Component Image Component Symbol Component Name Wire
Toggle switch
Pushbutton switch
Relay
Jumper
Dip switch
Resistor Variable resistor / Rheostat Potentiometer
Capacitor
Variable capacitor
Electrolytic capacitor
Inductor
Battery
Voltmeter
Lamp / Light bulb
Diode
BJT Transistor
MOS transistor Optocoupler / optoisolator Electric motor
Transformer Operational amplifier / 741 Crystal oscillator
Fuse
Buzzer
Loudspeaker
Microphone
Antenna / aerial
Passive components
Passive components do not need additional power source to operate and can not have gain.
Passive components include: wires, switches, resistors, capacitors, inductors, lamps, ...
Active components
Active components need additional power source to operate and can have gain. Active components include: transistors, relays, power sources, amplifiers, ...
Diode symbols
The diode is a semiconductor device that allows the current flow in one direction only. Valve electronic two electrodes called anode or plate and cathode electrode that uses the rectifying properties of a material type P and N semiconductor.
- These symbols can be represented within a circle.
Symbology
Diode symbol semiconductor, rectifier general symbol
Diode symbol semiconductor, rectifier general symbol
Diode symbol
Zener diode limiting diode unidirectional breakdown
Zener diode
Zener diode
Zener diode
Zener diode
Varicap diode Varactor
Varicap diode Varactor
Varicap diode Varactor
Gunn Impatt diode
Voltage suppressor Bidirectional breakdown Diode
Voltage suppressor Diode
Constant current diode
Recovery diode instant Snap
Tunnel diode
Tunnel diode
Tunnel rectifier diode
Schottky diode
Pin diode
Pin diode
Photodiode
LED light emitting diode
Photodiode NPN bidirectional
Photodiode two segments PNP common cathode
Photodiode two segments PNP common cathode
Laser diode
Magnetic diode
Temperature sensitive diode
Diode NPN Bidirectional breakdown
Diode PNP Bidirectional breakdown
Bridge rectifier by 4 diodes
Bridge rectifier by 4 diodes
7-Segment display LED diodes
Bicolor LED dual polarity
5x7 LED alphanumeric sample letter A
Tiristor SCR e dodo:
No caso do tiristor SCR este se assemelha a uma fechadura pelo fato da corrente poder fluir pelo dispositivo em um nico sentido, entrando pelo terminal de anodo e saindo pelo terminal de catodo. No entanto difere de um diodo porque mesmo quando o dispositivo est diretamente polarizado ele no consegue entrar em conduo enquanto no ocorrer a ativao do seu terminal de controle (terminal denominado porta, ou gate em ingls)
Reostato
Funo um resistncia varivel com dois terminais, sendo um fixo e o outro deslizante. Geralmente so utilizados com altas correntes. Variao Contnua: O reostato de variao contnua, comumente denominado potencimetro, apresenta uma resistncia que pode ter qualquer valor entre zero e um valor mximo especfico. Simbolo Foto
Potencimetro
Funo um tipo de resistncia varivel comum, sendo normalmente utilizado para controlar o volume em amplificadores de udio, variadores de tenso, tudo o que ajustvel em funo de um valor varivel de uma resistncia. Simbolo Foto
Resistor symbols
The resistors are passive components manufactured specifically to deliver a given value of resistance to the passage of electric current. The resistors are mainly classified into fixed, variable and special.
Um resistor (frequentemente chamado de resistncia, que na verdade a sua medida) um dispositivo eltrico muito utilizado em eletrnica, ora com a finalidade de transformar energia eltrica em energia trmica por meio do efeito joule, ora com a finalidade de limitar a corrente eltrica em um circuito.[1] Resistores so componentes que tm por finalidade oferecer uma oposio passagem de corrente eltrica, atravs de seu material. A essa oposio damos o nome de resistncia eltrica, que possui como unidade o ohm. Causam uma queda de tenso em alguma parte de um circuito eltrico, porm jamais causam quedas de corrente eltrica. Isso significa que a corrente eltrica que entra em um terminal do resistor ser exatamente a mesma que sai pelo outro terminal, porm h uma queda de tenso. Utilizando-se disso, possvel usar os resistores para controlar a corrente eltrica sobre os componentes desejados. Um resistor ideal um componente com uma resistncia eltrica que permanece constante independentemente da tenso ou corrente eltricaque circular pelo dispositivo. Os resistores podem ser fixos ou variveis. Neste caso so chamados de potencimetros ou reostatos.
Variable resistor Rheostat
Variable resistor preset
Variable resistor Rheostat
Variable resistor preset
Step varaible resistor
Impedance
Step varaible resistor
Variable resistor Potentiometer
Resistor of variation continuous
Variable resistor Potentiometer
Thermistor, NTC Negative temperature coefficient
Preset potentiometer
Thermistor, PTC Positive temperature coefficient
Thermistor
Photoresistor, LDR Light dependent resistor
Varistor, VDR Voltage dependent resistor
Photoresistor, LDR Light dependent resistor Varistor, VDR Voltage dependent resistor
Photoresistor, LDR Light dependent resistor
Varistor, VDR Voltage dependent resistor
Photoresistor, LDR Light dependent resistor
Varistor, VDR Voltage-dependent resistor
Resistor with power supply
Resistor with fixed tappings
Resistor dependent magnetic field
Attenuator
Protection resistor Protection resistor
Resistor not flammable
Heating element
Preset resistor Derivation resistor connections current and voltage
