×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

telephone switch hold

telephone switch hold

telephone switch hold

(OP)
I know this one is a little out there, but thought I'd try...at my company, we have a stand alone cd player that is used for music for people on hold.  It is (was before I got here and no one here knows, etc..) wired from the headphone jack into 2 wires on the connector strip (the switch?) but nobody knows what they are....anyways, there is a lot of static on the music (on the callers phone) on the outside line.  It's definately the connection to the switch and I am just curious what those 2 wires may be going to concerning the phone system.  Also, I was thinking a small cap between the 2 wires may clean up the noise, or is that just a stupid thought?

Any comments are appreciated...

Thanks,
Mark

RE: telephone switch hold

If I remember corectly, a hold is caused when a 10K resistance load is placed on the line.  I would suggest an isolation transformer between the CD player and the phone line.  There may be a ground problem between these items or the output cap may be breaking down because of the higher or reversed voltage on 1t.  You might start by using a non polarized 1uF at at least 100V to couple the signal.  Next try a 10K to 10K audio isolation transformer.  The 1uF may still have to be used on the line side.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources