Electronic Circuit Symbols

• The document shows electronic symbols and their names.

Circuit Symbols

• Crossing wires without conductive connection shown as a cross of two lines.
• Arrangement where one line crosses another with a dot indicates a conductive connection.
• A battery (primary/secondary cell) or accumulator has a long line and short line.
• Photoelectric cell or photocell has the battery symbol and two arrows hitting it.
• A voltage source with voltage indication has a circle with + and - symbols, as well as voltage, e.g., 24 V
• Direct voltage is a squiggly line.
• Alternating voltage is a sine wave.
• Ground is shown as three shorting lines, decreasing in size.
• Fuse is a rectangle.
• Coil, winding, or inductance is a curly line.
• Switch (general) is a line starting unconnected and moving downwards to connect, other side is shorting line:
  • The left version is a normally open switch, and the right version is a normally closed switch.
• Changeover switch with break left.
• Changeover switch with center position OFF right.
• Manually operated switch, general (normally open,) is a straight line connected to an angled line.
• Manually operated switch, normally closed, is a straight line connected to an angled line touching the connection.
• Manually operated switch, general (latching and normally open) has a slanted line connecting with a perpendicular line and a small angled line.
• Changeover switch with break, manually operated, latching, has a slanted line connecting with a perpendicular line, and a small angled line.
• Relay coil, drive with make contact has rectangle connected to slanted line.
• Relay coil, drive with break contact has rectangle connected to slanted line touching horizontal connection.
• Relay coil, drive with changeover contact, has rectangle connected to three lines.
• Relay coil, surge relay has a coil driving a zig-zag line.
• Reed contact is a horizontal lozenge shape.
• Resistor, temperature-dependent, NTC resistor (thermistor) is a rectangle with a line through it, a temperature line and headed down.
• Resistor, temperature-dependent, PTC resistor (cold conductor,) is a rectangle with a line through it, a temperature line and headed up.
• Capacitor, general, has two parallel lines.
• Electrolytic capacitor has a filled in line and open line.
• Semiconductor diode, general, is a filled in triangle touching a line.
• Light-emitting diode, LED, is a filled in triangle touching a line with two arrows pointing away.
• Photodiode is a filled in triangle touching a line with two arrows pointing inwards.
• NPN transistor
• PNP transistor
• NPN phototransistor
• Darlington transistor
• NOT element has 1 input, a box, and 1 output.
• AND element has 2 inputs, a box, and 1 output.
• OR element has 2 inputs, a box, and 1 output.
• NAND element has 2 inputs, a box, and 1 output.
• NOR element has 2 inputs, a box, and 1 output.
• Lamp, general, indicator lamp is a circle with an X in it.

General Symbols

• Generator is a circle with a G in it (left) and Motor is a circle with an M in it (right).
• Voltmeter or voltage measuring device is a circle with a V in it.
• Ammeter or current measuring device is a circle with an A in it.
• Ohmmeter or resistance measuring device is a circle with an omega symbol in it.
• Left represents buzzer or chime, right represents buzzer or snatcher.
• Interval signal generator
• Resistor, general is a rectangle.
• Adjustable resistor.
• Resistor with wiper contact, potentiometer.
• Resistor, light-dependent, LDR (photoresistor).