This is a very small telephone exchange system with two ordinary telephones attached. Full bi-directional facility with an intercom system: when a phone is in off hook condition , the circuit will detect it & send ringing pulse to the other phone. When it will be picked up , the connection will be established between both phones. This will take place vice-versa also. This project sounds great if you need a simple and efficient communication system, like in a tree house, you place on telephone in the tree house and the other one in your house. This is just an example but there are far more applications for this system.
Two way telephone system: [Link]
CMoy is a very simple and portable headphone amplifier. The amplifier was originally posted by Chu Moy on headwize.com. Headphones amplifiers are usually used when the output of a device is to low for the kind of headphones you’re using, or to get better sound quality by keeping the device on a medium volume setting and amplifying the sound with the headphone amplifier. I’ve not build this amplifier so far, so i cant tell you from my personal experience if it sounds good or bad, but from what i read on the internet, users that build it are very happy with the results. The schematic is very simple, parts are easy accessible so it should go really smooth with the building process if you decide to do it.
CMoy Headphone Amplifier: [Link]
Make a sound card is no more a complex issue. If you use great IC PCM2702 from BURR BROWN / Texas Instruments you can create a fully functional USB sound card. This sound card can be powered from USB port and has one stereo output. You don’t need to install any driver for Windows XP and Vista, because they are already inside. This is really plug and play.
DIY Sound Card with PCM2702: [Link]
This circuit is a church bell controller. If you’re not familiar with the idea, it basically sounds a bunch of bells after different melodies and the effect is pretty neat. The controlling is done by an ATmega32 microcontroller hooked up with a 24LC32 memory. For controlling the author implemented a 4×20 LCD and 6 buttons at the face of the circuit’s box (Menu, Up, Down, Enter, Start, Stop). Among the features are :
- More 75 different melodies (ADAM, PANYGJRJKO, AGJORJKO, etc)
- Percussion of clock each half but also entire hours, with possibility of choice of hours of silence (for tourist regions and hours of common quietness).
- When it runs a rhythm you have the possibility of increase or decrease its speed, the information will stored in memory 24LC32.
- Control up to 5 bells and 1 clock.
I must say this is the first project of its kind id seen.
Project Author: Antonis Pontikakis
Church Bell Controller can controll up to 5 bells and 1 clock: [Link]
WIMP is a project developed by 5 students as the 4th year project and supervised by Professor Trevor W. Pearce of the Department of Systems and Computer Engineering at Carleton University. But, what the heck is WIMP ? As the title says its a wireless interactive media player, basically a MP3 stereo system with a wireless link to a PC. Currently the students are still working on the project, but I can see some serious applications, for this system in the future, so good luck guys in finishing the project and scoring nice grades.
Wireless Interactive Media Player (WIMP): [Link]