Free Transistor Circuit Diagram Maker

See it work

Transistor circuit diagram examples.

Same tool, four requests. Every drawing below is a real render.

What you type

Draw a 9 V NPN common-emitter amplifier with a 100 kΩ and 10 kΩ bias divider, 2.2 kΩ collector resistor, 1 kΩ emitter resistor, 100 µF bypass capacitor, and 10 kΩ collector load.

Then tryRemove the emitter bypass capacitor.Change the collector resistor to 4.7 kΩ.

Circuit schematic: NPN common-emitter amplifier

Circuit schematic · IEEE Std 315 / ANSI Y32.2 · schematex-circuit

Rather start from a finished drawing? Browse 361 circuit diagram templates →

The drawing

What a transistor circuit is.

A transistor circuit uses a small control signal to switch or regulate a larger current. BJTs use base current, MOSFETs use gate voltage, and JFETs are often chosen for high-input-impedance signal stages.

The schematic needs the supply, the transistor terminals, the bias or gate network, the load, and any protection components. Those details show whether a device is intended to operate as a switch, current driver, or linear amplifier.

Standard: IEEE Std 315 / ANSI Y32.2
Engine: schematex-circuit
Editable: Double-click text, drag nodes
Export: SVG · PNG · PDF

Circuit schematic: What a transistor circuit is

Who uses it

Who uses transistor circuit diagrams.

Makers

Low-side MOSFET switches for LED strips, motors, and other DC loads controlled by a small sensor or board output.

Electronics students

BJT bias and common-emitter stages for understanding operating points, gain, and signal inversion.

Audio builders

High-impedance JFET input stages for piezo pickups before volume and tone controls.

How it works

How to make a transistor circuit diagram in three steps.

Describe it

One paragraph is enough to start.

“Draw a 9 V NPN common-emitter amplifier with a 100 kΩ and 10 kΩ bias divider, 2.2 kΩ collector resistor, 1 kΩ emitter resistor, 100 µF bypass capacitor, and 10 kΩ collector load.”

See the drawing

Drawn by the right engine.

Say what changes

Every edit keeps a version.

Remove the emitter bypass capacitor.

V2 · DRAWN FROM V1, NOTHING RETYPED

FAQ

Common questions

What transistor circuits can I diagram?

You can describe BJT switches and amplifiers, MOSFET load drivers, JFET preamps, Darlington stages, relay drivers, sensor interfaces, and push-pull stages.

What is the difference between a BJT and a MOSFET?

A BJT is controlled by base current, while a MOSFET is primarily controlled by gate voltage. The right choice depends on the supply, load current, switching speed, and available drive signal.

Why does a transistor need bias resistors?

Bias resistors set a predictable operating point for an amplifier or limit drive current for a switch. They help prevent the transistor from being unintentionally off, saturated, or overstressed.

Do inductive loads need protection?

Yes. A relay, solenoid, or motor can create a voltage spike when switched off. A suitable flyback diode or other suppression network protects the transistor and nearby electronics.

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