Content for 2N3904

2N3904

The 2N3904 is a common NPN bipolar junction transistor used for general-purpose low-power amplifying or switching applications. It is designed for low current and power, medium voltage, and can operate at moderately high speeds. It is a 200 mA, 40 V, 625 mW transistor with a transition frequency of 300 MHz, with a minimal beta, or current gain, of 100 at a collector current of 10 mA. It is used in a variety of analog amplification and switching applications.

Advanced Sensitive Lightning detector with PC Graph

“Simple to build, but serious instrument for monitoring and predicting weather disasters. Lightning detectors are devices designed to detect the presence of lightning strikes. These detectors utilize various technologies to sense the electromagnetic signals like detecting of Radio Frequency (RF …

Simple Sensitive 3 Transistors BFO Metal Detector

“If properly adjusted according to the instructions, it is able to detect a small coin at a distance of 15 cm In this project I will present you a Very Simple “Beat Frequency Oscillator” type of Metal Detector. BFO metal …

Ventbot, a DIY Home HVAC Vent Booster: Warm Side Cool, Cool Side Warm

“Do you have rooms in your house that are colder than other rooms in the winter? If you have air conditioning, are those same rooms warmer than other rooms in the summer? It’s common for that to happen to …

Electronic Puzzle Cube

“This is the Technological Tesseract—an electronic puzzle box. The goal of this puzzle is to connect three wires to the jacks in the correct configuration to make the LED matrix light up in a fun way. There are four …

Speed Reading LTC

“An adaptive decoder for LTC data This is my third (and probably last) post on the topic of Arduino interrupts and timers. In the first two, we discovered how to generate regular interrupts with precise timing, then how to use …

DIY Portable Alarm System

“When I was a kid, there were several political murders in the ex-YU that involved people who had Surveillance Systems that mysteriously stopped recording during the event and resumed without an issue immediately afterward. Weird right? With no evidence …

Arduino Cranial Stimulator (Bio-BrainTuner)

“Cranial electro stimulation uses harmonic frequencies to help balance the brain’s chemistry. Cranial electro stimulation uses harmonic frequencies to help balance the brain’s chemistry. By connecting with the body’s control center, the brain harmonic frequencies provide wide-ranging …

100 LED Oscilloscope

“This is my next build using LED matrix’s. You may have seen my last one - 81 LED Chaser, well this project uses 100 LED’s and is an oscilloscope! Admittedly, the resolution isn’t great for checking measurements (it …

Measuring Circuit Delay for FPGA Timing using the ADP3450

“Using the ADP3450, this project measures amount of delay between asserting FPGA IO on base of NPN 2N3094 and LED illuminating on collector. Signal timing is a huge component in FPGA design, and while many tutorials demonstrate how to handle …

Build a Laser Harp From Scratch

“This is actually a really simple circuit, using just one hex-inverter chip and a handful of small, common components. Discover step-by-step how this circuit works by building it on breadboard first with a detailed guide. Finally, build the finished instrument …