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kemo-kojak siren

Discussion in 'Electronic Design' started by *paolino Q*, Apr 25, 2008.

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  1. *paolino Q*

    *paolino Q* Guest

    I have found ,for bicycles of my niece , schematic of a typical kojak
    siren but without list of components .
    I thought of finding , by experiment , the close frequency and getting
    the just values of resistences and capacitors but I cannot well get them ;
    does anyone , that bought the kit kemo or similar one , know them ? The
    scheme is here :

    http://attach.mynl.it/img?id=NzQ0Ng

    These are my tried values :

    R1=R4=R7=R10=R5== 560 OHM
    R2=r3=R8= R6=r9= 22000 , 2200 ,33000 ,68000

    c5=c6 = 22 nano F

    C2=C3= 47 micro F

    Transistors =bc547 c & bd242
     
  2. Bob Monsen

    Bob Monsen Guest


    R1 12k
    R2 100k
    R3 100k
    R4 10k
    R5 47k
    R6 100k
    R7 10k
    R8 100k
    R9 100k
    R10 10k

    C1 22uF
    C2 0.47uF
    C3 0.47uF
    C4 0.1uF
    C5 0.01uF
    C6 0.01uF

    Instead of using R11 into T5, you need more drive. Use another npn in a
    darlington configuration:


    View in fixed-width font:

    12 o----------------------o------.
    | |
    | |
    | |
    | | __ /|
    | '--| | |
    | .--|__| |
    R11 | | \|
    ___ |/ |
    From -----|___|------| |
    Oscillator |> |
    100k | |
    | |/
    '----|
    | |>
    .-. |
    10k | | |
    | | |
    '-' |
    | |
    | |
    0 o-----------------------o------'
    (created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)


    That should scream pretty annoyingly.

    Regards,
    Bob Monsen
     
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