BH14115F transmitter project

Discussion in 'Wireless & RF Design' started by SteveyD, Oct 24, 2009.

  1. SteveyD

    Thread Starter New Member

    Jan 20, 2008
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    BH1415F transmitter

    I been working on this project off and on for a while now and I've completed etching the board and soldering all the components. Except one.

    The L2 coil (20mh)

    I have contacted the author of the project and he identified L2 as a TOKO CLNS-80036z. He sent me to a parts vendor and its out of stock. Both the Author and the vendor were unable or unwilling to give me any additional information or an alternate.

    I have been unable to find this coil anywhere, I even emailed TOKO international without a response.

    Could one of you Guru's take a look at the link and offer an alternate part or perhaps a vendor that sells this coil?

    Thanks
    Steve
     
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    The coil L2 is used for the pilot tone adjustment.
    See the datasheet for more info.

    Greetings,
    Bertus
     
  3. SteveyD

    Thread Starter New Member

    Jan 20, 2008
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    Bertus,

    Thank you for identifying exactly what L2 does in this circuit.

    Now to find a compatible component, I'm not eager to just start stuffing in coils and applying power to see if it works.


    EDIT** I mislabeled the part.. Its L1 I'm looking for...
     
    Last edited: Oct 24, 2009
  4. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I see it too, but it is the one between pins 19 of the chip and ground.
    It is the filter for the pilot tone.
    The circuit needs probably to be tuned at 19 kHz.
    The frequency calculated give 21.6 Khz at 20 mH.

    Greetings,
    Bertus
     
    Last edited: Oct 24, 2009
  5. SteveyD

    Thread Starter New Member

    Jan 20, 2008
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    0
    Thanks for the assistance Bertus

    I just discovered a new page Another BH1415F Transmitter also created by the same author.

    In this circuit which is nearly identical, it identifies L1 as a 20uh and not a 20mh coil even though the part is still the same.

    I guess having the correct value of this part will go a long way in finding a suitable alternate.
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    That is strange. That will shift the frequency by a factor of SQR(1000) = 31.6
    The frequency can be calculated as:

    [​IMG]

    Greetings,
    Bertus
     
  7. bertus

    Administrator

    Apr 5, 2008
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  8. SteveyD

    Thread Starter New Member

    Jan 20, 2008
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    Thanks Bertus

    I was looking at that design earlier but went with the other and completed the board over a few months, just need the coil to complete this project and move on to another project.

    Steve
     
  9. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    There seems to be an other number for the coil.
    The coil seems to be 20 mH (22 ± 10 %)
    See the datasheet .

    Greetings,
    Bertus
     
  10. SteveyD

    Thread Starter New Member

    Jan 20, 2008
    6
    0
    Thanks again Bertus,

    I'm going to try the alternate part number to see if i can order it.

    Steve
     
  11. rjenkins

    AAC Fanatic!

    Nov 6, 2005
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