Knock on the box, and a grumpy little monster pops out to see who’s there. I built this Halloween project for my daughter was she was only two and didn’t like scary things. So I wanted to build something cute and fun instead. Here’s my mini monster box: A microphone hears the knock, a one-transistor
Circuits & Projects
How do you become better at electronics? By building lots of circuits.
On this page, you’ll find circuit diagrams for a wide range of fun and interesting electronic circuits:
Transistor circuits. 555 Timer Circuits. LED Circuits. Amplifier circuits. And many more.
All circuits come with a component list and a connection diagram, schematic, or build instruction. So you can just start building right away.
If you have any questions about the circuits, just ask in the comment section of the circuit you’re curious about.
The “Bedroom-Door-Open” Notification Gadget
I built a “door opened” notifier. It notifies me if my young daughter opens the door to her room. This way, I can work on projects in my workshop at night, and still know if she decides to not go to sleep. Maybe this will be useful for when she gets older to avoid her
Simple FM Transmitter for Hobbyists
Build a compact FM transmitter to experiment with RF circuits. With this circuit, you will be able to transmit your voice over short distances using basic components. Building your own FM transmitter is a great way to experiment with electronics and learn more about how radio frequency works. This circuit is perfect for electronics hobbyists
Remote Controlled On-Off Switch Project
This tutorial will guide you through building a simple remote-controlled on-off switch that will work with most IR remote controls. And you only need four components to build it. It works like this: Every time you push a button on the remote control the signal is received an converted into one long pulse that toggles
How To Build a USB Flashlight: A Simple DIY Tutorial
This tutorial will guide you through building a basic USB-powered light with five Light-Emitting Diodes (LEDs). You can expand on this and put it into a casing with a switch to create your very own USB flashlight from scratch! This project is great for beginners who want to learn about basic electronics and soldering. Materials
Touchless Kitchen Lighting with Arduino and Phototransistor
Here’s a cool Arduino project I did to bring a bit of high-tech magic to my daughter’s toy kitchen. She can now turn on the lights in her toy kitchen with a simple wave of her hand! My daughter has been excited about the thought of getting lights in her kitchen. And I was excited
Arduino PIR Sensor Circuit and Code Example
In this tutorial, you’ll learn how to create an Arduino PIR Sensor. PIR stands for Passive InfraRed. The PIR sensor is widely used in motion detection applications and this project will show you how to use it to control an LED. When the sensor detects motion, the LED will turn on and the event will
555 Timer Police Lights
This 555 Timer Police Lights circuit is an interesting electronics project that simulates the alternating flash of police vehicle lights using LEDs.
The circuit uses a 555 timer IC and a CD4017 decade counter to create the flashing effect. By adjusting the frequency of the 555 timer, you can control how quickly the LEDs flash, mimicking the strobe light effect found on emergency vehicles.
555 Timer Continuity Tester
A continuity tester is an indispensable tool when working with electronic circuits. This 555 Timer Continuity Tester uses a 555 Timer IC to generate an audible tone when a continuous path (continuity) is detected between the two probes. This tester will work with resistances up to 200 kΩ. Additionally, it has an automatic turn-off feature
555 Timer Reaction Game
The 555 Timer Reaction Game is a simple and fun project that tests your reflexes. Using the classic 555 timer IC in conjunction with a CD4026 decade counter with 7-segment output, you can create a game that challenges players to press a button as quickly as possible after a signal starts. Player 1 uses the
555 Timer TV Remote Jammer – Complete Instructions
Here is a nifty little circuit that’s designed to make sure nobody messes with your TV settings while you are watching your favorite show – a 555 timer TV remote jammer! This sneaky device sends out an invisible signal at a frequency that the TV thinks is coming from a remote control. But instead of
555 Timer Music Box – a Synthesizer with 10-Tone Sequencer
This is a fun project to build – a 555 Timer music box! It’s based on two 555 timers, one that sets the tempo of the music, and one that creates the different tones. The sequence of which tones to play is managed by a decade counter IC and some resistors. The Circuit You can
555 Timer Railroad Lights
This is a 555 Timer railroad lights project where two lights are alternating, similar to a railroad crossing signal. The 555 timer is set up in astable mode so that it keeps switching its output between HIGH and LOW, thereby turning on and off the two LEDs connected to the output. The Circuit To build
555 Timer Machine Gun Sound Effect
This 555 Timer machine gun circuit generates a sound that mimics the sound of a machine gun. It is based on a 555 timer IC, which is a popular chip used for creating pulses and timing circuits. The Circuit To build this circuit you’ll need a 555 timer, a speaker, a few capacitors, and a
555 Timer Metronome Circuit
The 555 timer IC is a versatile component that can be used in various circuits, including a metronome. A metronome is a device used by musicians to keep a steady tempo during practice. In this tutorial, you’ll learn how to build a simple metronome using the 555 timer IC. Parts List 1 × 9V Battery