ring detection n phone answering

Status
Not open for further replies.
In order to take the phone "off hook" it is only necessary to put a load on the line. You also need a way to take the load off the line (put the phone "on hook". When the phone is off hook, you can inject a signal current which will be sent to the calling phone. The circuit below was used for a telephone telemetering device. The capacitors keep the phone off hook for a short time while the data is being transmitted. The 78l05 provides power to the data circuit.
 

Attachments

  • telckt.jpg
    35.7 KB · Views: 486
Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…