NPN transistor symbol
Also called Bipolar transistor, BJT
An NPN bipolar transistor: a small base current controls a larger current from collector to emitter. The arrow on the emitter points out.
What the NPN transistor symbol means
An NPN bipolar transistor: a small base current controls a larger current from collector to emitter. The arrow on the emitter points out.
ANSI and IEC symbols
Base bar, collector and emitter, with the emitter arrow pointing out, usually inside a circle.
ANSI SVGWhere you see it
Switching relays and LEDs from logic outputs, amplifiers and driver stages.
What is written next to it
On a schematic, the NPN transistor usually carries its designator and part number, such as Q1 BC547.
Related symbols
Frequently asked questions
What does the NPN transistor symbol look like?
On ANSI drawings: Base bar, collector and emitter, with the emitter arrow pointing out, usually inside a circle. In IEC 60617: The same lines and outward arrow, usually without the circle.
Is the NPN transistor symbol the same in IEC and ANSI?
No. The same lines and outward arrow, usually without the circle.
Where is a NPN transistor used?
Switching relays and LEDs from logic outputs, amplifiers and driver stages.
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