I recently was browsing electronic kits on various websites and noticed that there seemed to be a few component testers that can be bought, some are assembled and others need…

The 4067 was one of the IC’s that I wanted to connect up to various microcontrollers as it looke dextremely useful, here is a quick description from one of the datasheets…

Another sparkfun design here for a simple board that takes a 4-9V input voltage and outputs a selectable 1.8V or 3.3V regulated voltage. Based on the LM317 again   Bill…

An open source power supply based on the LM317, the voltages are switchable using SW2 Parts List Part Value Device Package Description C1 100uF CAP_POLPTH1 CPOL-RADIAL-100UF-25V Capacitor Polarized C2 10uF…

A DIY Arduino board which you can etchby hand and solder it together. It is pin-compatible with the Arduino Diecimila, and should work with any Arduino shield. EAGLE files (.zip)…

the Freeduino MaxSerial, designed by Fundamental Logic Derived under CC2.5 from the Freeduino files above and the Arduino Diecimila schematic Download Eagle files for the schematic and the board  …

the Freeduino Serial, designed by NKC Electronics Derived under CC2.5 from the Freeduino files above and the Arduino Serial 2.0 schematic Download Eagle files for the schematic and the board…

Schematics of a phase control circuit (simplified), used for dimming a light   Source : wikipedia

by Tony van Roon Use this circuit instead of a standard on-off switch. Switching is very gentle. Connect unused input pins to an appropriate logic level. Unused output pins *MUST*…

As shown in the schematic above, when a inductor coil L1 is brought near the wire carrying the audio signal, the audio signal will be induced into the coil and…