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  • can u tell me whether this circuit is having some error or not

    prasadaraju

    Member

    Updated: Oct 26, 2024
    Views: 1.2K
    #-Link-Snipped-#

    this is the link of my mini project
    i have selected

    but i came to knoe that some error is there in the circuit
    now i have no choice to change my project
    can u help me in corecting that
    plzzzzzzzzzzzzzz
    0
    Replies
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Replies

  • prasadaraju

    Member • Aug 22, 2009

    plz help me

    😕
    Electronic Key Operated Security Door

    this is the link of my mini project
    i have selected

    but i came to knoe that some error is there in the circuit
    now i have no choice to change my project
    can u help me in corecting that
    plzzzzzzzzzzzzzz
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  • prasadaraju

    Member • Aug 22, 2009

    can u tell me whether this circuit is having some error or not
    Electronic Key Operated Security Door
    #-Link-Snipped-#

    this is the link of my mini project
    i have selected

    but i came to knoe that some error is there in the circuit
    now i have no choice to change my project
    can u help me in corecting that
    plzzzzzzzzzzzzzz
    Are you sure? This action cannot be undone.
    Cancel

  • prasadaraju

    Member • Aug 22, 2009

    plzz help me

    #-Link-Snipped-#
    this is the link of my mini project
    i have selected

    but i came to knoe that some error is there in the circuit
    now i have no choice to change my project
    can u help me in corecting that
    plzzzzzzzzzzzzzz
    Are you sure? This action cannot be undone.
    Cancel

  • Munguti

    Member • Aug 23, 2009

    What is the error? do you undestand the circuit?
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  • prasadaraju

    Member • Aug 24, 2009

    hi

    can u tell me whether error is there or not
    plz
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  • prasadaraju

    Member • Aug 24, 2009

    when i started my project
    whenever 7 is pressed the o/p is coming directly then what iis need of this 1,4,7 code
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  • reachrkata

    Member • Aug 24, 2009

    Firstly let me indicate my understanding of the circuit -

    1) The opto gets on when 1,4,7 are pressed in that sequence alone.
    2) Normally S12 is closed by which IC1D always has an input.
    3) If 1,4,7 in the correct sequence is pressed, IC1C pin 9 will drive the opto.
    4) If any wrong number is pressed, pin 12 of IC1D goes high, pin 10 goes high and remains high because of the latching action (short of B & C). This High signal through R6 turns on Q2, in turn making IC1A pin 1 low. This ensures that if subsequently the correct code is pressed also nothing happens.
    5) Pressing S1 to clear everything, turns on Q1, in turn making pin 12 of IC1D low (and it remains low). This turns off Q2 and again makes IC1A pin 1 high (which is the default).
    6) Releasing S12 also has the same action - makes Pin 10 of IC1D low, in turn turns off Q2 and so on.

    Now to come to our problem - the only reason why the opto is turning on by pressing 7 alone is because of the value of R1. If the value of R1 is such that only by pressing 7 also, the current through the LED is not enough to excite the photo-transistor, then everything will work. Only R7 should be capable of turning on the opto.

    Hope this clarifies !

    -Karthik
    😁
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  • prasadaraju

    Member • Aug 24, 2009

    1.so is this circuit works correctly
    there are any mistakes in the circiut or not
    if i connect it as given in the diagram can i get output
    and how to see output (at which pin of optocoupler and by placing led at 5th pin of optocoupler ca i observe output)

    2.how to press 1,4,7 whether in a sequence or i have to press three of them to observe ouput

    3.if i press 7 then optocoupler is directly getting the voltage
    is it true(this is i observed from figure)
    plz tell me is it truee

    4.what is the use of optocoupler
    can u tell me why optocoupler is used inthis circuitttttttt
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  • reachrkata

    Member • Aug 25, 2009

    1) Yes the circuit is correct. No mistakes. No need of the Opto to check the output. Just check the voltage at IC1C pin 9. It will be High if you have pressed the correct keys.

    2) Press 1,4,7 one after the other (like how you would key in your PIN in the ATM machine). No need to press together.

    3) Yes it is true, but whether the LED will work or not depends on the current through the LED. Therefore you should choose R1 such that the current is lower than the minimum current required to turn on the LED of the Opto.

    -Karthik
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  • prasadaraju

    Member • Aug 25, 2009

    as there is optocoupler used in the circuit i should show the o/p after the optocoupler
    then how to show o/p at optocoupler(by using what .)

    you hvae told r1 should be some value(can u tell me the vvalue of it plzz)
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  • rushi53

    Member • Aug 26, 2009

    prasadaraju
    #-Link-Snipped-#

    this is the link of my mini project
    i have selected

    but i came to knoe that some error is there in the circuit
    now i have no choice to change my project
    can u help me in corecting that
    plzzzzzzzzzzzzzz

    sorry dear,
    I am not able to open the link

    just tell me 1 thing, are you using microcontroller in that circuit ?
    if yes, then I can definitely guide you in that.

    __________________
    Thanks,
    Rushikesh
    <a href="https://www.projectsof8051.com" target="_blank" rel="nofollow noopener noreferrer">Microtronics Technologies - Projects of 8051 AVR PIC Arduino & Raspberry Pi</a>
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  • prasadaraju

    Member • Aug 27, 2009

    nooo im not usingggggggggggggggggggggg micro conttroller
    in that
    can u try it plz
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  • prasadaraju

    Member • Aug 27, 2009

    #-Link-Snipped-#
    u can see it in this site
    plz help me
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  • prasadaraju

    Member • Aug 27, 2009

    4.what is the use of optocoupler
    can u tell me why optocoupler is used inthis circuitttttttt
    #-Link-Snipped-#


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