Getting and injectingan audio signal at the same time from/to phone

Discussion in 'General Electronics Chat' started by xfiles, Apr 24, 2007.

  1. xfiles

    Thread Starter New Member

    Apr 24, 2007
    1
    0
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Make sure your device has a characteristic impedence of 600 ohms and a bandwidth of 300-3300 Hz . Make sure it can withstand 90Vac ringer voltage on the signal line. If it is to run off the phone line voltage, make sure it runs on 48Vdc.

    Then simply connect it in parallel with the phone line.
     
  3. Gadget

    Distinguished Member

    Jan 10, 2006
    613
    0
    Most telcos frown upon installing anything in their line without first isolating it with a 600ohm:600 ohm transformer.
     
Loading...