Dimmers and HT

Discussion in 'Home Theater Projects' started by itai, Apr 30, 2004.

  1. itai

    itai Stunt Coordinator

    Joined:
    Jan 23, 2002
    Messages:
    221
    Likes Received:
    0
    Hi all
    I've noticed interferences on the TV screen, (a new Phillips 36" 16:9 beast) when the light dimmers in the living room (where the TV's at) are working.

    if they're closed shut, or at full strength, the picture is clean. It shows when either of the dimmers, even across the room, is engaged. (Gevis dimmers)
    the TV shows crawling dots and slight noise. you can see it when the DVD is stopped, and sends a black picture to the TV.

    The electricity was renovated (as the whole apt), and was upgraded to triple phase (sorry, i don't know the exact term in English).

    Any help will be appreciated!
    Thanks.[​IMG]
     
  2. Ethan Winer

    Ethan Winer Stunt Coordinator

    Joined:
    Apr 6, 2004
    Messages:
    95
    Likes Received:
    0
    Itai,

    Solid state dimmers are notorious for this. See the "Hum and Buzz" article, 4th in the list on my Articles page:

    www dot ethanwiner dot com/articles.html

    In particular, see the section that explains how to use variable transformers as dimmers. I'm not sure what voltage you have in Israel, but the concepts are exactly the same.

    --Ethan
     
  3. itai

    itai Stunt Coordinator

    Joined:
    Jan 23, 2002
    Messages:
    221
    Likes Received:
    0
    Thanks Ethan
    I guess I'll have to install variable transformers as you explain.
    We have 220v in israel. I have an uncle who's an engineer, he will read your explanations, as I've no clue about electricity.
    He also (as you suggest) installed a regular switch to turn the dimmers on and off simply, and he'll probably enjoy reading your article.
    Thanks!
    ps, can it harm the equipment? (the tv?)
     
  4. Ethan Winer

    Ethan Winer Stunt Coordinator

    Joined:
    Apr 6, 2004
    Messages:
    95
    Likes Received:
    0
    Itai,

    > can it harm the equipment? (the tv?) <

    Do not use a variable transformer with the TV! It's for dimming the lights only, and only for use with incandescent (filament) light bulbs - not flourescent bulbs.

    --Ethan
     
  5. Derrik Draven

    Derrik Draven Supporting Actor

    Joined:
    Dec 7, 1998
    Messages:
    935
    Likes Received:
    1
    Real Name:
    Chris
    I have 4 rows with 5 halogen track lights on each row, overhead in my ht.

    Originally, I put sliding dimmers on each light switch but, the noisy grrrrowwwwllll, that the transformers would make when adjusting the lighting, made me just say "screw it", and I put on/off switches in instead. Total silence now.

    Take out the dimmers if you can.
     
  6. itai

    itai Stunt Coordinator

    Joined:
    Jan 23, 2002
    Messages:
    221
    Likes Received:
    0
    i'm not using the dimmers with the tv!!!! that's not what i meant...
    i meant, can the (expensive) tv set be harmed by the noise in the current (seen on its screen).
    the tv is plugged into a separate socket, in the same room as the dimmers.
    thanks for your help anyway!
     
  7. Ethan Winer

    Ethan Winer Stunt Coordinator

    Joined:
    Apr 6, 2004
    Messages:
    95
    Likes Received:
    0
    Itai,

    > can the (expensive) tv set be harmed by the noise in the current <

    Probably not.

    --Ethan
     
  8. MikeWh

    MikeWh Second Unit

    Joined:
    Mar 3, 2003
    Messages:
    407
    Likes Received:
    0
    Nice article, Ethan.

    itai--- in addition to Ethan's information in the article, you should be familiar with one of the most frequently mentioned design suggestions for electrical wiring in a home theater--- it is HIGHLY suggested that you place your audio and video equipment on a separate phase from any circuits with dimmers on them. Of course, it looks like you are in a newly renovated apartment, so it's apparently too late for you....

    As far as your issue is concerned, you may also be able to replace the dimmer(s) with higher quality dimmers. This may be a hit-or-miss solution however. I have three Smarthome dimmers that are all the same model, but one of the dimmers has a very slight, but noticeable hum in it. Apparently, you may find different reactions from individual dimmers and their specific loads.
     
  9. itai

    itai Stunt Coordinator

    Joined:
    Jan 23, 2002
    Messages:
    221
    Likes Received:
    0
    thank you guys,
    yes, we learn things the hard way...
    [​IMG]
     
  10. John Sayers

    John Sayers Auditioning

    Joined:
    Apr 9, 2004
    Messages:
    5
    Likes Received:
    0
    itai - here's a link to the Luxtrol var- trans dimmers.


    www dot superiorelectric dot com/WEB_voltage/luxtrol-c dot pdf

    cheers
    john
     

Share This Page