Circuit Examples

Learn by changing a working circuit. Each example in CircuitBench is designed to demonstrate a specific electronics or Arduino concept that you can inspect, modify and simulate in your browser.

Click any card below to open that circuit in the simulator, or choose one from the Examples… menu inside it. Change component values or code, run the simulation again, and compare what happens.

Beginner circuits Arduino projects Sensors Outputs Electronics Experiment ideas

Beginner circuits

Ohm's law dividerUse a battery and two resistors to see how current and voltage change when resistance changes. Blink an LEDThe classic first Arduino project: digital output, timing and a current-limiting resistor. Button toggleRead a pushbutton with INPUT_PULLUP and use its state to control an output. Potentiometer fadeTurn an analog input into a PWM output and vary LED brightness.

Arduino projects

These examples connect a board, components and C++ code. They are useful for learning how software changes physical circuit behavior.

Blink an LEDLearn setup(), loop(), pinMode(), digitalWrite() and delay(). Button toggleRead a digital input and react to a button press. Potentiometer fadeRead analog input and map it to PWM. Piezo melodyUse an output device to create tones and timing patterns. Servo sweepControl a servo angle from Arduino code.

Sensors and inputs

Ultrasonic distanceUse the HC-SR04 to measure distance and inspect the timing signals. LCD + DHT22Read temperature and humidity and display the values. PhotoresistorBuild a voltage divider and watch an analog reading respond to light. PotentiometerUse a variable resistor as an adjustable analog input.

Outputs and actuators

ESP32 + NeoPixelsControl addressable RGB LEDs and experiment with color values. ServoMove a servo through a range of angles using Arduino code. Piezo buzzerCreate tones and simple melodies with timed output. Transistor + motorUse a transistor and flyback diode so a board can control a motor safely.

Electronics experiments

The examples are also useful without Arduino. Try changing values and measuring the result rather than treating the circuit as a fixed recipe.

Voltage divider: change either resistor and predict the middle-node voltage before running the simulation.
LED resistor: change the supply voltage or resistor and observe how current changes.
RC circuit: change resistance or capacitance and compare the time constant τ = R × C.
Transistor switch: compare a direct motor connection with a transistor-driven circuit.

How to experiment

A useful simulation experiment changes one variable at a time. First predict what should happen, then run the circuit and inspect the voltages, currents or scope trace.

Load an example from the simulator.
Identify the component or line of code you want to investigate.
Change one value, such as a resistor, delay or sensor input.
Run the simulation and record what changed.
Reset or export the circuit if you want to compare another version.

Challenge: load Potentiometer fade, change the resistor or PWM mapping, and predict how the LED brightness will respond before pressing Start.

Need the basics first? Read Electronics Basics, work through the Getting Started Guide, or browse the Component Library.

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