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.

Main Content

Aiie! - an embedded Apple //e emulator

“A Teensy 4.1 running as an Apple //e Teensy 4.1 (600 MHz arm Cortex M7) running a full-speed Apple //e emulator. Because everyone needs one of these, right?”

Whistle Controlled Robot

“This robot is completely guided everywhere by whistle, much like the “Golden Sonic Toy” made in 1957. When switched on, the robot moves in the direction indicated by the illuminated arrow on the front drive wheel mechanism. When the whistle …

Led Matrix With Arduino

“This Is A Led Matrix Which Uses 74HC595 Shift Register & CD4017 Decade Counter , Its Very Simpe To Make This Project If You Follow My Steps Given Below I Have Simplified The Steps And Explained Everything For Better Understanding . Done With …

Voicetron - Voice Recording Toy

“This device was created for pleasure and inspiration for anyone who would like to make a simple voice recorder for their children to play, or as a decoration, or use in Geocaching or in escape rooms. There are many possibilities …

ESP-01 CONTROL RGB LED CUBE 4x4x4

“ESP-01 ESP8266 can be used as a stand-alone device to control a RGB led cube 4x4x4. Today, I’d like to share how ESP-01 ESP8266 can be used as a stand-alone device to control a RGB led cube …

Building a Chaotic Oscillator from Common Components

“A chaotic oscillator is an electronic circuit that can exhibit “chaotic“, nonperiodic behavior. A commonly cited example is Chua’s circuit, but there are many others. I always regarded these as carefully designed, rather academic, examples. So I was a …

Atmega328P Fuse Reset

“Instruction Manual PDF has all the necessarily files and schematics for the build. Introduction This project uses the Arduino Nano Microcontroller to reset Fuse bytes and erase Flash and EEPROM for ATMEGA 328/328P. By using the Arduino Nano with …

ATtiny13 TinyRemote SMD

“IR remote control based on an ATtiny13A powered by a CR2032 or LIR2032 coin cell battery. The code is a full implementation of the NEC protocol using only 370 bytes (36%) of program memory.”

How to Make Joule Thief Circuit

“in this tutorial, lets build a joule thief circuit”

Capacitor Leakage Tester

“This tester can be used to check smaller value capacitors to see if they have leakage at their rated voltages. It can also be used to test insulation resistance in wires or to test a diode’s reverse breakdown characteristics …