This PCB drill is made of wood and looks really cool. Wouldn’t mind to have one on my table. Design is very unique - it uses various custom made parts, motors from old printers and VCR’s. Author even simulated all design code on a Labcenter’s Proteus VSM.

“Made from Dremel drill and drill press. I removed the bottom plate & mounted the column to the back with U-bolts. Acrylic is so easy to work with. It can be cut, drilled milled & glued and it’s very strong, doesn’t warp or break easily. The design is the same as the big PCB drills, the table moves, not the drill head. With the exception the real machine tables I’ve worked around ride on air. Like the old air hockey tables Important note: These NEMA teen motors don’t have enough torque to drive the table (no bearings).”

Miniature fires that flicker create the sense that someone is nearby in a model scene. They can add a moving effect to a dolls’ house, model railroad or Christmas Village scene.This fire will be created using a set of LED’s especially for the purpose of fire from Evans Design. As this fire is going to be part of a portable table display, a 9 volt battery will be used to power the LED’s which in this case are designed for DC (direct current) use.

In this project I created an infrared (IR) link that provides bi-directional communication between the NXT and the new Power-Functions system, which consists of a battery box, motors, a remote control (an IR transmitter) and an IR receiver that controls the motors.

I previously built an IR transmitter for the NXT which used an MSP430 microcontroller and which was able to send Sony IR commands (the specifications of this protocol are widely available). In this project, I wanted to achieve three additional goals:

* To analyse the Power-Functions IR protocol, for which no documentation is publicly available.
* To build a system that could not only send IR commands, but could also receive and decode them.
* To experiment with AVR’s, another family of microcontrollers.

There were several reasons that I wanted to experiment with the AVR’s. Compared to the MSP430 microcontrollers, the AVR family offers many more chips in DIP packages (large but easy to prototype with), they run at wider supply voltages (most can tolerate at least 2.7-5.5V and some operate down to 1.8V), and their pins can supply a lot of current (up to 40mA for a single pin). The wide range of supply voltages means that they can be connected to the 4.3V supply of the NXT’s ports directly without a regulator, and the ability of the pins to supply a lot of current simplifies some circuits, such as when the chip needs to drive a bipolar transistor or a LED. Another advantage of the AVR is that they can be programmed using a wide variety of simple circuits, not just with proprietary programming devices.

This is a tiny GPS logger based on the San Jose Navigation FV-M8 GPS module that stores coordinates, altitude, and speed into an EEPROM. Then a software converts EEPROM stored data into *.kml (Google Earth format). Altitude and speed graphs are also generated by the software.

I want to build high quality preamplifier with built-in DAC from SPDIF or USB for my power amplifier Leachamp.  I tried to design DAC from USB with this circuit on one-sided PCB and I was successful.

Schematics is from datasheet of PCM2902. Circuit includes DAC and ADC, SPDIF output and input and HID part with 3 buttons for MUTE, VOL+ and VOL-. I used only DAC part. Other parts are not used. For high quality playback is needed to use external low-drop voltage stabiliser for DAC part. I used LP2951CM which was available at local store. Output voltage is set to about 3.7V with two resistors. Circuit board is designed regarding to good ground placement and separating of analog and digital ground. These ground are connected in one point at USB connector.

The purpose of this timer is to provide a countdown time from 1 second to 99 minutes & 59 seconds. I use it to control the lighting for the Ultra-Violet exposure of photosensitive PCB material. The project provides also an audible alarm at the end of the countdown time and switches the UV lights by means of a relay. It is based on a Microchip microcontroller, the 18 pin PIC16F84(A). This microcontroller contains 1Kbyte of flash memory for program code, 64bytes of static RAM memory, and 64bytes of EEPROM memory which are used here to store up to 15 different (user-programmable) countdown times.