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Circuitry design

Discussion in 'General Electronics Discussion' started by Corrector, Oct 24, 2012.

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  1. Corrector

    Corrector

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    Oct 5, 2012
    I included http://www.epanorama.net/circuits/tm_adapt.gif into this: http://i.imgur.com/FwG8f.jpg

    The goal of the circuitry is to take the output of my computer's headphones speaker which is at about 2.4 Volts Vpp(You see that as jack symbol in the upper left of http://i.imgur.com/FwG8f.jpg) and to mix both signals using the virtual mass opamp circuitry. Then the signal is fed into a 600Ohms:600Ohms transformer's central tapping. According to http://www.epanorama.net/circuits/tm_adapt.gif this should be the tape out connection ie. audio source. After the transformer the signal should be mixed with the wave of the phone line.

    What do I need to change for my circuity to transmit well-audible audio into the telephone line?

    Right now it is almost quiet.
     
    Last edited: Oct 24, 2012
  2. GreenGiant

    GreenGiant

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    Feb 9, 2012
    Well...
    this depends on what you are connecting it to for speakers, are you using headphones? Or a set of speakers alone? Or a set of speakers with an amp?

    2.4Vpp is a little low for most speakers, you typically need somewhere around 4Vpp or higher, this system also seems to be very low power, I would recommend connecting it to an amplifier at the other end, and play it through that, yes you will get noise, but you should be able to hear it at least a little better
     
  3. Corrector

    Corrector

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    Oct 5, 2012
    GreenGiant, I did some corrections to my original post.

    I just saw that this post travelled at least 4000 miles from germany, cologne to usa,Massachusetts
     
    Last edited: Oct 24, 2012
  4. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Where did you find this schematic?
    http://www.epanorama.net/circuits/tm_adapt.gif

    The zeners and the 10KΩ resistors are presumably there for ring voltage protection but the 10KΩ resistors leaves next to no audio power to drive the 600Ω tel line. While we're on the subject the tel line is a 600Ω balanced DC loop when off hook.

    Chris
     
  5. Corrector

    Corrector

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    Oct 5, 2012
    What you are saying: "This will never work".
    What I want you to say: "This is what you should do to make it work".
     
    Last edited: Oct 25, 2012
  6. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    Have a look at this webpage. In the lower third of the page there is an article about telephone hybrid circuits (In German ;) ).
     
  7. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    Read the full article from which you have taken the telephone hybrid circuit.
    My rather limited knowledge of telephone circuits tells me that Chris is right in questioning the 10k resistors.
    Look at the ASCII schematic under the heding "Simple telecom hybrid circuits". It is basically the same as your circuit but without alll the caps, resistors and zeners.
     
  8. Corrector

    Corrector

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    Oct 5, 2012
    Why don't you just recommend someone who knows his stuff and the pitfalls of those phone circuits?

    That leads to the telephone to be excluded, ie I cannot dial, cannot listen, cannot talk using my phone. Using the other circuitry that worked, so "alll the caps, resistors and zeners" do have a purpose.
     
  9. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    Do I know that someone?

    In your first post you say it didn't work :confused:
     
    Last edited: Oct 25, 2012
  10. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    This forum is based on using English as a common language. Please adhere to netiquette and use English, too. As you rightfully noticed, there's not just you and me in this thread.

    By the way: just because my location is Germany and I do speak German, who says I'm German?
     
  11. BobK

    BobK

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    Ja, wir sprechen kein Deutsch hier.

    Bob
     
  12. Corrector

    Corrector

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    Oct 5, 2012
    Wenn ich dich adressiere, werde ich deutsch sprechen. Adressiere ich alle, spreche ich englisch. Und dabei bleibe ich, auch wenn es dir nicht gefällt. Sollen die Englischsprechenden Google Translate bemühen, wenn sie unser Privatgespräch verstehen wollen - und von ihrem hohen Roß herunterkommen und eine weitere Sprache neben ihrer Muttersprache Englisch lernen. Mag sein, daß viele Deutsche einen Schuldkomplex haben und ihnen ihre Muttersprache peinlich ist, ich habe keinen und lasse ihn mir auch nicht einreiden.

    translation: If I address you, I will speak German. Redirect all I, I speak English. And I stand by, even if you do not like. Should endeavor English speakers Google Translate, if they want to understand our private conversation - and come down from their high horse and learn another language besides their native language English. It may be that many German have a guilt complex and give them their first language is embarrassing, and I do not leave him to me either einreiden.
     
    Last edited by a moderator: Oct 25, 2012
  13. Corrector

    Corrector

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    Oct 5, 2012
    Which is why I won't talk german to you. Speaking of which: Can you answer the main question?

    I succeeded at short circuiting the 10kohms resistors. Now it's louder. A bit.
     
    Last edited: Oct 25, 2012
  14. CocaCola

    CocaCola

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    If there is one way you want to start off on the wrong foot, it's ignoring common forum etiquette and doing things that annoy or isolating those that might be inclined to actually help...
     
  15. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    Ich denke, dass dies kurz davor ist, sehr hässlich zu werden!

    You can take that for what it's worth but please consider the following:
    How many languages exist on this earth? If you knew the answer could you speak all of them? I'm fortunate that I speak the language that's considered universal and it's good that we have one. If my history serves me correctly things could be very different for you and me. 1945 could very well have culminated in the international language you prefer. However, since things didn't quite work out that way, how about we all just try to get along? .. Capice??

    Chris
     
  16. CocaCola

    CocaCola

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    Cute...

    Says you? Since you don't know me from anyone, how can you begin to speculate one what languages I know and can speak, that is beyond English? FYI: factoid to you, I speak 3 languages (or at least can stumble by with the other 2 enough to carry on a conversation), as well as being fluent in American sign language and several different programming languages...

    Thanks for your immature uniformed opinion on the matter...

    Speak it all you want, but it's only polite to speak the language of the host while in their house especially when they have requested you to do so...

    Why because couldn't read it? :rolleyes: It was a silly rub that clearly did it's job and ruffled your feathers because it drove home the point...
     
  17. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    I think I'll give Corrector a 24 hour break to reconsider his/her use of language.
     
    Last edited: Oct 25, 2012
  18. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    May 8, 2012
  19. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    Good thing you did this. I feel Icouldn't have done it because I'm too involved - one could take this as a personal reaction from me.
     
  20. donkey

    donkey

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    If I goto japan I won't expect them to speak english, or if I goto serbia I won't expect it. But when you enter a predominantly speaking culture (including this forum) is it not respectful to adhere to the majority not the minority?
    a forum is about provoking a stimulating chat. as a point of respect would it not be better to promote that by talking in a language we can all follow?
    your posts may be by you for your project to begin with, but we ALL surf and find new things out, like how to google images, how solar works, the ways to utilise a 555timer..,... etc. etc.
    by having the exact same information in several different languages on the same site takes room. I expect this forum is limited to the amount of bytes it can hold and thus having it in one language the vast majority of the world understands would be the RESPECTFUL thing to do.
     
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