LED series parallel combination problem

Discussion in 'General Electronics Chat' started by shiva007nand, Oct 19, 2015.

Thread Status:
Not open for further replies.
  1. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    Hello, I am using non isolated constant current source driver,
    I am using 0.2 watt 2835 package LED which drops 2.5 volts.

    I have some data which I had checked myself practically.
    Input Voltage Type Output Voltage Type Output Voltage without load Output Current Load Power
    230 AC 73.4 DC 110.7 99mA 48 LED 7.3 W

    230 AC 77 DC 95.8 131mA 48 LED 10.087

    LEDs are connected in the way of 2 parallel and one serial, so total 48 LED. Like 24 LED in series with 2 LED parallel for each combination.

    Input Voltage Type Output Voltage Type Output Voltage without load Output Current Load Power
    230 AC 74.2 DC 100 249.5mA 96 LED 18.51 W
    LEDs are connected in the way of 4 parallel and one serial, so total 96 LED. Like 24 LED in series with 4 LED parallel for each combination.

    I do not know How output voltage varies or what is combination for it.
    How can I apply KCL for above combination ??
     
  2. TheButtonThief

    Active Member

    Feb 26, 2011
    219
    38
    LED output voltage?
    Input voltage type?
    Output voltage type?
    Output current load power?

    Sir, thou speaketh in riddles.
     
  3. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,520
    1,247
    Do you really think you can accurately describe series/parallel arrangements of 48 and 96 LEDs in one sentence each? In a foreign language? Think. This is an electrical engineering forum, and a schematic diagram is the universal language. No schematic, no answer.

    And, what does KCL mean?

    ak
     
    TheButtonThief and shiva007nand like this.
  4. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    Okay,
    KCL is Kirchoffs current law.
    I am trying to upload schematic diagram but I do not know what is problem
    It is showing me a block message on top of it.
     
  5. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    Input voltage 230 volt Alternating Current
    Output voltage type is Direct current
    output current value
    and load means combination of LED series and parallel - how much LED are connected with it
    Power - It means how much energy it consumes in watt
     
  6. TheButtonThief

    Active Member

    Feb 26, 2011
    219
    38
    Fine

    How do LEDs have an output voltage?

    Again, how does an LED output a current?

    Yep, I Know what a load is. However, "output current load power" doesn't make sense

    Please...
     
  7. dl324

    Distinguished Member

    Mar 30, 2015
    3,242
    619
    Are you trying to post a photo format?
     
  8. dl324

    Distinguished Member

    Mar 30, 2015
    3,242
    619
    Some of your formatting was lost. What are the three lines of information for?
     
  9. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    Yes I was trying to post images
    Anyways here I have attached schematic diagram,I you still find it difficult to understand
    I will make required changes in it.
     
    • 66.pdf
      File size:
      703 KB
      Views:
      13
    • 67.pdf
      File size:
      684.4 KB
      Views:
      11
  10. dl324

    Distinguished Member

    Mar 30, 2015
    3,242
    619
    You shouldn't connect LEDs in parallel without ballast resistors; even very small differences in Vf can result in objectionable differences in brightness.

    What is the operating current for the LEDs, how many will you have in series, and what are the power supply output specs?
     
  11. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
     
  12. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    Operating current is constant for LED 115 mA to 249 mA as per need, different watt.
    I have 24 led in series, as per above attached schematic diagram.
    power supply output is direct current it varies according to your load i.e. series parallel combination of LED
     
  13. dl324

    Distinguished Member

    Mar 30, 2015
    3,242
    619
    I thought it was established in your other thread that max current for your LEDs was 90mA continuous and 120mA peak for < 100uS at a 20 or 25% duty cycle.
     
  14. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    90 mA is maximum forward current for LED package of 2835.
    so if we use more than 90 mA, we have to get current divided using parallel combinations.
    continuous current range of my drivers is from 60 mA to 249 mA
     
  15. TheButtonThief

    Active Member

    Feb 26, 2011
    219
    38
    My brain is fried.

    I'm still unsure what the OP is asking us...
     
  16. shiva007nand

    Thread Starter Member

    Sep 25, 2015
    38
    1
    see I am asking about I know the current which is I am giving to the circuit, I know the
    schematic diagram of it.
    But I am lagging to find out that how much voltage it needs ??
    If I get simple formula for one schematic diagram which is attached above, I can make other every possible combination to find output voltage

    I am trying to use kirchoffs current law for above schematic diagram.
     
  17. TheButtonThief

    Active Member

    Feb 26, 2011
    219
    38
    Are you asking us to tell you what voltage you need to supply to the circuit?

    By "output voltage" do you mean "supply voltage"?

    Why? What are you hoping to calculate?
     
  18. ScottWang

    Moderator

    Aug 23, 2012
    4,853
    767
    The owners of All About Circuits has elected not to host discussions of transformerless threads.

    This thread is against the AAC forum rules, Terms of Service (ToS).

    Any kind of over-unity devices and systems
    Devices designed to electrocute or shock another person
    LEDs to mains
    Phone jammers
    Rail guns and high-energy projectile devices
    Transformer-less power supplies
    Terms of Service (ToS).

    Transformerless power supplies of any kind are strictly forbidden. Therefore, this thread will be closed.

    Please try to understand the reasons behind this action, and feel free to browse and use the forums.

    You might find answers to your questions in one of these forums:

    http://forum.allaboutcircuits.com/showthread.php?t=54400

    Another good forum that shares many of the same membership is http://www.electro-tech-online.com/ .

    Good luck.
     
Loading...
Thread Status:
Not open for further replies.