help needs! (electronics stuff)

Discussion in 'The Projects Forum' started by jinjay09, Jan 8, 2014.

  1. jinjay09

    Thread Starter New Member

    Jan 8, 2014
    hi all!
    i have very low, lake knowledge on electronics! so i need your help!
    i am doing kind of experiment about frequency, sound, installation with power socket.

    what i am trying to make is i hook the frequency, energy of the power socket of building to amplifier and make a noise of the building. usually, on the wall two power sockets are together next of each. i plug an amplifier in one power socket. for another, i took main cable (sealed) and connected to 6.35mm audio ject and it goes to amplifier (refer the pics below).
    for making the main cable to connect with 6.35 audio ject, i ask to electronics shop staff and he said it needs to be done as inductive coupling with Fixed Inductive (the blue little square thing on the pic, don't know the name of it to english,,,), instead of making direct connection to the audio ject.
    and then, he said i can just tapping it on sealed main cable (like the pics below.
    and i tested it, but couldn't hear any sound from the amp...
    can anyone give me advices pls???????????



  2. JohnInTX


    Jun 26, 2012
    Yes. Stop what you are doing immediately.

    If I read your pictures right, you have blown the input of your amplifier by putting 240VAC across the (low voltage) input. I don't know what the guy was telling you but you are lucky to be alive - or at least lucky not to have blown a fuze.

    I don't know what you mean by building noise, presumably something that 1)isolates the low voltage amplifier input from the 240VAC power and 2)filters out the 50HZ hum so that you can get whatever signal is left.

    Please stop until you can consult with someone who knows what they are doing.
    absf and DerStrom8 like this.
  3. DerStrom8

    Well-Known Member

    Feb 20, 2011
    No, he is okay. He did not actually connect the 240VAC to the low voltage input. What he did was put what appears to be an inductor on the amp input, and placed it *next to* a mains cord, the idea being the amp would pick up the radiated electro-magnetic field surrounding the cord.

    To the OP: This probably won't work, since you don't have a complete circuit on the cord you're "listening" to. You'd have better luck putting the "sensor" (or "pickup wire") next to the cord connecting the amp to mains. That way it's self-contained. Either way you'll probably need a complete circuit in order for your sensor to pick up the field.

    jinjay09 and JohnInTX like this.
  4. JohnInTX


    Jun 26, 2012
    Whew! Looking again, I think you are right. Thanks, Matt. There isn't much current to be sensed running in the non-loop though.. Maybe a dummy load?

    Spooky. Brrrr.
    DerStrom8 likes this.
  5. DerStrom8

    Well-Known Member

    Feb 20, 2011
    Haha no problem. I had a little trouble reading his initial post and after reading your response I got rather nervous myself! I took a closer look at his pictures though, and things seem to be safe at least.

    Not sure of a good dummy load you could use that wouldn't waste power.

    I still think the OP's best bet would be to simply couple the "sensor" with the mains cord of the amp. It's already there, why not put it to use? ;)

    JohnInTX likes this.
  6. JohnInTX


    Jun 26, 2012
    Yeah. Split the leads of the power cord and tape the sensor to one leg.

    For the OP.. why?

    "Nighttime in the building. A building with secrets. Secrets that one man tries to know. Secrets in the noise. Its.. Building-noir. Coming to a theater near you. Soooon."
    Sorry - couldn't resist.
    Last edited: Jan 8, 2014
    DerStrom8 and KJ6EAD like this.
  7. MrChips


    Oct 2, 2009
    I can hear Moody Blues "Nights in White Satin" in my head.


    Because I'm wearing pajamas made by "Nights in White Flannel"?
  8. inwo

    Well-Known Member

    Nov 7, 2013
    Pick a frequency range and you should get some help with coupling.