Symbol | Component name | Meaning | Real world example |
---|
Wire Symbols |
---|
 | Electrical Wire | Conductor of electrical current |  |
 | Connected Wires | Connected crossing |  |
 | Not Connected Wires | Wires are not connected |  |
Switch symbol |
---|
 | 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 | DIP switch is used for onboard configuration |  |
 | SPST Relay | Relay open / close connection by an electromagnet |  |
 | SPDT Relay |  |
 | Jumper | Close connection by jumper insertion on pins. |  |
 | Solder Bridge | Solder to close connection |  |
Ground Symbols |
---|
 | Earth Ground | Used for zero potential reference and electrical shock protection. |  |
 | Chassis Ground | Connected to the chassis of the circuit |  |
 | 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) |  |
 | Trimmer Resistor | Preset resistor |  |
 | Thermistor | Thermal resistor – change resistance when temperature changes |  |
 | Photoresistor / Light dependent resistor (LDR) | Photo-resistor – change resistance with light intensity change |  |
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 | Adjustable capacitance |  |
Inductor / Coil Symbols |
---|
 | Inductor | 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 |  |
 | Generator | Electrical voltage is generated by mechanical rotation of the generator |  |
 | Battery Cell | Generates constant voltage |  |
 | Battery | Generates constant voltage |  |
 | Controlled Voltage Source | Generates voltage as a function of voltage or current of other circuit element. |  |
 | Controlled Current Source | Generates current as a function of voltage or current of other circuit element. |  |
Meter Symbols |
---|
 | Voltmeter | Measures voltage. Has very high resistance. Connected in parallel. |  |
 | Ammeter | Measures electric current. Has near zero resistance. Connected serially. |  |
 | Ohmmeter | Measures resistance |  |
 | Wattmeter | Measures electric power |  |
Lamp / Light Bulb Symbols |
---|
 | Lamp / light bulb | 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 (anode) to right (cathode). |  |
 | Zener Diode | Allows current flow in one direction, but also can flow in the reverse direction when above breakdown voltage |  |
 | Schottky Diode | Schottky diode is a diode with low voltage drop |  |
 | Varactor / Varicap Diode | Variable capacitance diode |  |
 | Tunnel Diode | |  |
 | Light Emitting Diode (LED) | LED emits light when current flows through |  |
 | Photodiode | Photodiode allows current flow when exposed to light |  |
Transistor Symbols |
---|
 | NPN Bipolar Transistor | Allows current flow when high potential at base (middle) |  |
 | PNP Bipolar Transistor | Allows current flow when low potential at base (middle) |  |
 | Darlington Transistor | Made from 2 bipolar transistors. Has total gain of the product of each gain. |  |
 | JFET-N Transistor | N-channel field effect transistor |  |
 | JFET-P Transistor | P-channel field effect transistor |  |
 | NMOS Transistor | N-channel MOSFET transistor |  |
 | PMOS Transistor | P-channel MOSFET transistor |  |
Misc. Symbols |
---|
 | Motor | Electric motor |  |
 | Transformer | Change AC voltage from high to low or low to high. |  |
 | Electric bell | Rings when activated |  |
 | Buzzer | Produce buzzing sound |  |
 | Fuse | The fuse disconnects when current above threshold. Used to protect circuit from high currents. |  |
 | Fuse |  |
 | Bus | Contains several wires. Usually for data / address. |  |
 | Bus |
 | Bus |
 | Optocoupler / Opto-isolator | Optocoupler isolates connection to other board |  |
 | Loudspeaker | Converts electrical signal to sound waves |  |
 | Microphone | Converts sound waves to electrical signal |  |
 | Operational Amplifier | Amplify input signal |  |
 | Schmitt Trigger | Operates 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 | Used to generate precise frequency clock signal |  |
Antenna Symbols |
---|
 | Antenna / aerial | Transmits & receives radio waves |  |
 | Antenna / aerial |  |
 | Dipole Antenna | Two wires simple antenna |  |
Logic Gates Symbols |
---|
 | NOT Gate (Inverter) | Outputs 1 when input is 0 |  |
 | AND Gate | Outputs 1 when both inputs are 1. |  |
 | NAND Gate | Outputs 0 when both inputs are 1. (NOT + AND) |  |
 | OR Gate | Outputs 1 when any input is 1. |  |
 | NOR Gate | Outputs 0 when any input is 1. (NOT + OR) |  |
 | XOR Gate | Outputs 1 when inputs are different. (Exclusive OR) |  |
 | D Flip-Flop | Stores one bit of data |  |
 | Multiplexer / Mux 2 to 1 | Connects the output to selected input line. |  |
 | Multiplexer / Mux 4 to 1 |  |
 | Demultiplexer / Demux 1 to 4 | Connects selected output to the input line. |  |