Connect with us

telecom

Discussion in 'General Electronics Discussion' started by selvam, Mar 28, 2015.

Thread Status:
Not open for further replies.
  1. selvam

    selvam

    5
    0
    Mar 28, 2015
    HI FRIENDS i am working as telecom technician.in my section under groundtelephone cables are affected by railway electric traction inductance. telecom signal voltage is 48-52 v dc .jan 15 started electric railway traction after that problem started .train moving time telecom cable voltage is reached 175 inductance volt.so telephone get humming noise.i put gas dischrge tube individualally still now fault is continued. so i decided to put inductor filter for blocks ac.but i dont know which value select inductor ,resitor .anyone can solve this problem means help me guys. i need blocks the ac inductance voltage
     
  2. davenn

    davenn Moderator

    13,319
    1,767
    Sep 5, 2009
    hi selvam
    welcome

    This is really a problem for your more senior engineers to work out
    not people on a forum with no firsthand access to the situation

    discuss it with those senior to you :)

    cheers
    Dave
     
    selvam and hevans1944 like this.
  3. selvam

    selvam

    5
    0
    Mar 28, 2015
    thank you :(
     
  4. Gryd3

    Gryd3

    4,098
    875
    Jun 25, 2014
    As Dave said, this should be carried out by someone in the field with working experience with your system and by someone who can held responsible for any faults that may arise.
    The unfortunate part of your problem here is that telecom lines work with a combination of DC and AC... so depending on how you filter the AC noise out, you could very well create problems with DSL, fax, and voice. Additionally, you can't just clamp the voltage to the desired working voltage because the noise would still be present and would most likely be heard as a square wave which is NOT very pleasing to the ear.
    It's very unfortunate... but it would seem the line was installed incorrectly. Running signal wires in parallel with noise generating lines is asking for trouble... This is why telecom and power lines are run independently through a home. In cases where this can't be avoided, there are various techniques to prevent noise such as shielding and twisted pair that can be used to help mitigate this.
    Once run... it can be very difficult to eliminate noise at either end of the line. I wish for you the best of luck in getting your problem resolved.
     
  5. davenn

    davenn Moderator

    13,319
    1,767
    Sep 5, 2009
    Damn I should have closed this thread the other day, long before you responded @Gryd3
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Thread Status:
Not open for further replies.
Electronics Point Logo
Continue to site
Quote of the day

-