The circuit was designed to provide a monitoring scheme for a telephone line where several phones are installed, to indicate when one is being used. 4N25 – a general purpose optocoupler that consists ...
The circuit aims to create a recording scheme not only for spying but for business purposes where conversations are noted for future reference. 4N28 – a general purpose optocoupler that consists of a ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results