News Item: Drwadio, A Pencil That can Draw Audio
(Category: Electronic Projects)
Posted by ajay_bhargav
Wed May 11 2011, 01:15 am

Drawdio is project that allows you to Draw Audio, you can make any Audio Pattern by drawing it using Lead Pencil. This Project is very easy to built uses simple Electronics components, totally Electronics Based no controller is used this, quite interesting for a person like me who love to make things using pure Electronics mean without using any controller

The Heart of this project is a simple Oscillator which is made by very familiar NEC555 which is in fact replaced by TLC551 in this circuit because of its high input impedance, very low power consumption and High output current capability. 555 requires 5 volts to operate mean minimum 3 primary cells so we are using 551 which can operate at 1 volt so we need only one AAA cell to get its working at up to 2MHz frequency which is quite handy and interesting.



In above Schematic you can see two boxes on TOP that are named as "TOP BOT" you have to connect these physically with inner core of Lead Pencil see images below how to do this.


In above pic you can see author is using copper tape to make connection but i know here in Asia especially in our region i.e Indo-Pak we people use these things very rarely if you have copper tape then you can use it if you didn't then i have solution for you, get a box of cigarette, Tore it and get Flavor Protecting Foil Paper (Reflective type Metal usually Aluminum Foil ) fold this paper and make a strip like copper tape used in above image, now use thumb pin to connect it with pencil core as shown i below image.



Now make another strip of that foil and turn it around the pencil like this

Here is you Complete Design

See this video to get its working.


Click Here to get PCB Layout and Complete Detail


This news item is from Rickey's World of Microcontrollers & Microprocessors
( http://www.8051projects.net/news.php?extend.170 )