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Modifying a led strip circuit

Discussion in 'LEDs and Optoelectronics' started by deepred, Mar 13, 2017.

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  1. deepred

    deepred

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    Mar 13, 2017
    Hi, I apologize for my English in advance, I'm stuck with a "maybe" simple problem, I'm a total newbie when it comes to electronics so im trying to make this led strip permanent on instead of switching led patterns
    http://imgur.com/a/0Yokv

    I had an old strip and randomly tried to shortcut some wires on the resistors in order to see the result, i know that was stupid, and no clues in the end beside a broken led string.

    Is it that complicated?
    Thanks in advance
     
  2. Audioguru

    Audioguru

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    Sep 24, 2016
    If the controller of your LED strip is designed to switch patterns then that is what it will do. If you want an LED strip to make permanent light then buy one that is designed to light permanently.
     
  3. deepred

    deepred

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    Mar 13, 2017
    Unfortunately that kind of LED strip wasn't available and still isn't I stupidly assumed just bypassing the switch button would have allowed me to set it to a fix pattern.
    Thanks for your reply
     
  4. Audioguru

    Audioguru

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    Sep 24, 2016
    Como estas, (my wife is from Spain but I don't speak much Spanish). Millions of LED strips are sold on ebay.
    My local electronics parts store has many LED strips.
     
  5. deepred

    deepred

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    Mar 13, 2017
    Hola to you too, I'm Italian tho :) the only ones i found according to my needing were those with a single colour and a button to make them light at various patterns, that's why i thought it was just a resistor value to be found and somehow replicated....It didn't worked obviously, the fact that i can change blinking patterns with a button is what gives me hope
     
  6. Audioguru

    Audioguru

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    Sep 24, 2016
    Do you want a one color LED strip to blink only one blinking pattern continuously? Then you must find or design and build a circuit that will do it.
     
  7. deepred

    deepred

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    Mar 13, 2017
    I just wanted to know if in the attached picture i can make that led stay lighted without blinking avoiding me to press 7 times the button every time i switch it on, i wanted to bypass the pressbutton somehow, just asking if possible or not
     
  8. Audioguru

    Audioguru

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    Sep 24, 2016
    You can design and build a circuit to electronically press the button 7 times each time it is turned on.
    Or you can trace the wiring of the LEDs then power them separated from the controller circuit.
    Your photo does not show the circuit (maybe it is a mini-computer) or its program.
     
  9. deepred

    deepred

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    Mar 13, 2017
    Thanks for the reply, later I'll try to upload a better picture so i can show the circuit since it's just Chinese led there should be no mini-computer involved.
     
  10. BobK

    BobK

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    Jan 5, 2010
    The LED strip itself will stay on continuously if powered continuously. You need to eliminate the controller and simply supply the correct voltage to the LED strip directly. Do you know the voltage? It is probably 12V but you would want to confirm that first.

    Bob
     
  11. deepred

    deepred

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    Mar 13, 2017
    Last time i checked it with a multimeter showed even peaks of 80/111v but I'm sure I checked the wrong wires, I'll be posting a better picture and check it better. Thanks for the reply, I'm trying to install 5 of those on the restaurant and it's annoying to press 7 times x 5 strips every time i open. I thought about putting an ESP8266 a d simulate the key press remotely but it seems a bit overkill
     
  12. deepred

    deepred

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    Mar 13, 2017
  13. Audioguru

    Audioguru

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    Sep 24, 2016
    Your meter probably cannot measure the short duration blinks, so measure the DC voltage that powers the controller circuit board instead. The controller is probably a black or white blob of plastic on the back of the circuit board that covers the mini-computer chip that creates the blinking patterns.

    Did you measure the voltage after pressing the button 7 times so that the LEDs are turned on continuously without blinking? Since you measure such a high voltage then maybe the LED strip has many LEDs connected in series like AC-powered Christmas tree lights. Or maybe they are small incandescent light bulbs that look like LEDs.

    Now I think the controller is powered from 220VAC without any isolation that is extremely dangerous.
     

    Attached Files:

  14. Audioguru

    Audioguru

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    Sep 24, 2016
    Then I am correct. This thing from India is extremely dangerous. Modern LED strings in the West are powered from 12VDC.
    Deep, is your name from India?
     
  15. deepred

    deepred

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    Mar 13, 2017
    You're right about everything on your picture! 220 comes from the wall directly in in two wires you indicated, as you said chips is that one and yeah, it's scary stuff I've been shocked once already lol
     
  16. deepred

    deepred

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    Mar 13, 2017
    No, it's not me I just found the link, I'm italian
     
  17. Audioguru

    Audioguru

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    Sep 24, 2016
    Dispose the dangerous junk and buy a safe 12VDC LED strip from The West.

    I saw a local store with high voltage neon lights in the window. The extremely dangerous high voltage transformer was laying where anybody could touch its connections. The store manager could not speeky zee Engrish so I showed the police. The transformer and neon lights were gone the next day.
     
  18. deepred

    deepred

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    Mar 13, 2017
    Those are even ipx "certified", i would have placed it on the roof, it's not possible for anyone to reach so it's not risky besides my safety, from the diagram on the Indian website i can see led are all connected to power except a stripe to ground, if from + to - I measure 12v can I just desolder it and wire directly to a wall transformer?
     
  19. Audioguru

    Audioguru

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    Sep 24, 2016
    The LEDs are probably connected all in series for each of the 4 wires then if there are 25 white 3V LEDs they need 75V. LED strips in The West use 3 LEDs in series and in series with a resistor and many groups like this all powered from 12VDC.

    The guy in India says, "The LEDs in each string are serially connected and each has 2M current limiting resistor."
    230VAC when rectified and smoothed produces 323VDC. If you touch it then the current is 323V/2M= 0.16mA which will give a noticeable shock but not kill you. Your reaction to the shock might kill you.

    Please get rid of these dangerous strings of electric shocks and buy safe ones.
     
  20. deepred

    deepred

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    Mar 13, 2017
    It was a light warming shock :) I measured the voltage between 1 led wire and ground and as you say it's something near the 80/100 value, not so stable. I'll try with a better LEDs, bought 4 of those for 70€ from England, couldn't imagine they were such bad stuff. Sadly i cant return it
     
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