All items tagged with phone and Free (3)

1-12-2010 | This project is built around an ARM microcontroller connected to the public telephone network. You can send commands to the microcontroller...

1-01-2004 | A headphone amplifier with outstanding sound quality can be built using readily available modern components. Omitting the output transformer...

1-12-2003 | Depending on local regulations and the telephone company you happen to be connected to, the voltage on a free telephone line can be anything...