Saturday 12 July 2014

Swarna Bharathi Institute of Science and Technology

Electrical Symbols & Electronic Symbols

SymbolComponent nameMeaning

Wire Symbols

electrical wire symbolElectrical WireConductor of electrical current
connected wires symbolConnected WiresConnected crossing
unconnected wires symbolNot Connected WiresWires are not connected

Switch Symbols and Relay Symbols

SPST switch symbolSPST Toggle SwitchDisconnects current when open
SPDT switch symbolSPDT Toggle SwitchSelects between two connections
push button symbolPushbutton Switch (N.O)Momentary switch - normally open
push button symbolPushbutton Switch (N.C)Momentary switch - normally closed
dip switch symbolDIP SwitchDIP switch is used for onboard configuration
spst relay symbolSPST RelayRelay open / close connection by an electromagnet
spdt relay symbolSPDT Relay
jumper symbolJumperClose connection by jumper insertion on pins.
solder bridge symbolSolder BridgeSolder to close connection

Ground Symbols

earth  ground symbolEarth GroundUsed for zero potential reference and electrical shock protection.
chassis symbolChassis GroundConnected to the chassis of the circuit
common digital ground symbolDigital / Common Ground

Resistor Symbols

resistor symbolResistor (IEEE)Resistor reduces the current flow.
resistor symbolResistor (IEC)
potentiomemer symbolPotentiometer (IEEE)Adjustable resistor - has 3 terminals.
potentiometer symbolPotentiometer (IEC)
variable resistor symbolVariable Resistor / Rheostat(IEEE)Adjustable resistor - has 2 terminals.
variable resistor symbolVariable Resistor / Rheostat(IEC)
Trimmer ResistorPreset resistor
ThermistorThermal resistor - change resistance when temperature changes
Photoresistor / Light dependent resistor (LDR)Photo-resistor - change resistance with light intensity change

Capacitor Symbols

CapacitorCapacitor is used to store electric charge. It acts as short circuit with AC and open circuit with DC.
capacitor symbolCapacitor
polarized capacitor symbolPolarized CapacitorElectrolytic capacitor
polarized capacitor symbolPolarized CapacitorElectrolytic capacitor
variable capacitor symbolVariable CapacitorAdjustable capacitance

Inductor / Coil Symbols

inductor symbolInductorCoil / solenoid that generates magnetic field
iron core inductor symbolIron Core InductorIncludes iron
variable core inductor symbolVariable Inductor

Power Supply Symbols

voltage source symbolVoltage SourceGenerates constant voltage
current source symbolCurrent SourceGenerates constant current.
ac power source symbolAC Voltage SourceAC voltage source
generator symbolGeneratorElectrical voltage is generated by mechanical rotation of the generator
battery cell symbolBattery CellGenerates constant voltage
battery symbolBatteryGenerates constant voltage
controlled voltage source symbolControlled Voltage SourceGenerates voltage as a function of voltage or current of other circuit element.
controlled current source symbolControlled Current SourceGenerates current as a function of voltage or current of other circuit element.

Meter Symbols

voltmeter symbolVoltmeterMeasures voltage. Has very high resistance. Connected in parallel.
ammeter symbolAmmeterMeasures electric current. Has near zero resistance. Connected serially.
ohmmeter symbolOhmmeterMeasures resistance
wattmeter symbolWattmeterMeasures electric power

Lamp / Light Bulb Symbols

lamp symbolLamp / light bulbGenerates light when current flows through
lamp symbolLamp / light bulb
lamp symbolLamp / light bulb

Diode / LED Symbols

diode symbolDiodeDiode allows current flow in one direction only (left to right).
zener diodeZener DiodeAllows current flow in one direction, but also can flow in the reverse direction when above breakdown voltage
schottky diode symbolSchottky DiodeSchottky diode is a diode with low voltage drop
varicap diode symbolVaractor / Varicap DiodeVariable capacitance diode
tunnel diode symbolTunnel Diode
led symbolLight Emitting Diode (LED)LED emits light when current flows through
photodiode symbolPhotodiodePhotodiode allows current flow when exposed to light

Transistor Symbols

npn transistor symbolNPN Bipolar TransistorAllows current flow when high potential at base (middle)
pnp transistor symbolPNP Bipolar TransistorAllows current flow when low potential at base (middle)
darlington transistor symbolDarlington TransistorMade from 2 bipolar transistors. Has total gain of the product of each gain.
JFET-N transistor symbolJFET-N TransistorN-channel field effect transistor
JFET-P transistor symbolJFET-P TransistorP-channel field effect transistor
nmos transistor symbolNMOS TransistorN-channel MOSFET transistor
pmos transistor symbolPMOS TransistorP-channel MOSFET transistor

Misc. Symbols

motor symbolMotorElectric motor
transformer symbolTransformerChange AC voltage from high to low or low to high.
Electric bellRings when activated
BuzzerProduce buzzing sound
fuse symbolFuseThe fuse disconnects when current above threshold. Used to protect circuit from high currents.
fuse symbolFuse
bus symbolBusContains several wires. Usually for data / address.
bus symbolBus
bus symbolBus
optocoupler symbolOptocoupler / Opto-isolatorOptocoupler isolates onnection to other board
speaker symbolLoudspeakerConverts electrical signal to sound waves
microphone symbolMicrophoneConverts sound waves to electrical signal
operational amplifier symbolOperational AmplifierAmplify input signal
schmitt trigger symbolSchmitt TriggerOperates with hysteresis to reduce noise.
Analog-to-digital converter (ADC)Converts analog signal to digital numbers
Digital-to-Analog converter (DAC)Converts digital numbers to analog signal
crystal oscillator symbolCrystal OscillatorUsed to generate precise frequency clock signal

Antenna Symbols

antenna symbolAntenna / aerialTransmits & receives radio waves
antenna symbolAntenna / aerial
dipole antenna symbolDipole AntennaTwo wires simple antenna

Logic Gates Symbols

NOT gate symbolNOT Gate (Inverter)Outputs 1 when input is 0
AND gate symbolAND GateOutputs 1 when both inputs are 1.
NAND gate symbolNAND GateOutputs 0 when both inputs are 1. (NOT + AND)
OR gate symbolOR GateOutputs 1 when any input is 1.
NOR gate symbolNOR GateOutputs 0 when any input is 1. (NOT + OR)
XOR gate symbolXOR GateOutputs 1 when inputs are different. (Exclusive OR)
D flip flop symbolD Flip-FlopStores one bit of data
mux symbolMultiplexer / Mux 2 to 1Connects the output to  selected input line.
mux symbolMultiplexer / Mux 4 to 1
demux symbolDemultiplexer / Demux 1 to 4Connects selected output to the input line.

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Article by
EEE Department
Swarna Bharathi Institute of Science and Technology

Swarna Bharathi Institute of Science and Technology