Looking for DIY master

Discussion in 'D.I.Y.' started by SilverJ87, Aug 27, 2017.

  1. SilverJ87
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    SilverJ87 Algae harvester

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    Morning all.

    Like the subject says I'm looking for someone that have decent knowledge about constant curret LED driver and 3w LEDs.

    Got a couple of questions before I continue with my current setup or if I should go with a new setup.

    Thank you
     
  2. Royden Church
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    Hi,

    Willing to help, tell me about your setup, equipment you have and any other questions.

    Regards
     
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  3. SilverJ87
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    SilverJ87 Algae harvester

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    I have these drivers for my current LED setup.
    Something is not clear it states Output 650maMax which i understand is 650ma but one LED is 350ma.
    I have ten LEDs running on a driver in SERIES connection.

    How is it possible to run the ten LEDs which in total is 3.5A or am I pushing the driver over the limit?
    Something I cannot understand the 10 leds will be running good and then after a couple of months will start flickering, nothing changed on the wiring.

    They say its a CONSTANT CURRENT driver so whats the difference?

    Is there a way to test the current flowing from nr 1 to nr 10?

    led.png
     
  4. f-fish+plants
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    f-fish+plants Aquascaper

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    Start here ... https://en.wikipedia.org/wiki/LED_circuit#frb-inline

    1) Is there a way to test the current flowing from nr 1 to nr 10? - Put the multimeter in series
    2) this is a 3 to 10 LED driver .. what is the forward voltage over each LED ( check the specification sheet )
    3) Do you have a resistor in your circuit ...
    4) I think you are over driving your LED's if they are only 350mA - you probably need to up that resistor.
    5 ) "flickering" that is probably the driver protecting itself - one of your LED is probably busy going south and then puts the entire string at risk.

    Have not looked deeply into the issues but the above should work as a starting point.

    Later Ferdie
     
  5. Royden Church
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    Royden Church Noob

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    Hi.

    If your using 3w Cree LED that might be your problem as the forward current is up to 700ma at 3.4v. LED will flicker if there is not enough current irrespective if the voltage is okay. [​IMG]

    Sent from my SM-G930F using Tapatalk
     
  6. SilverJ87
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    SilverJ87 Algae harvester

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    Thank you for all the answers so far.
    Did a quick search becoz i cannot remember the exact specs.
    DC Forward Voltage: 3.6V~3.8V Forward Current: 700mA
     
  7. Royden Church
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    The voltage will stay constant, but the current will vary as each LED draws a certain ampere, with all these combined the total current(Amp) being drawing is exceeding the supply.

    I am running a TC420 LED contoller with a 30A turned down to 10.5V supply, total LED's on my marine setup is 170w(17x 10W COB LED), thus my total current(Amp) being drawn from supply is only around 17 Amp. The controller can handle 4A per channel and there are 5 channels giving me a total of 20A or 240W of power at 12V.

    If I calculate correct according to your photo, you can run 6 x 3W LED on that supply.
     
  8. f-fish+plants
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    f-fish+plants Aquascaper

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    Not in a series circuit ... all the electrons are running at the same speed in one lane.

    700mA series draw for a supply that can only give a max of 650mA ...
     
  9. SilverJ87
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    So eventually i draw more amps out of the driver then the driver goes dead and cant handle so may leds? Bcoz in the beginning i can run 10full leds and after a while i can only get it to run say 8-9 at a time.. Is there a way to boost the Ma between the driver and the leds? Or another plan to make?
     
  10. f-fish+plants
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    Not worth the electronics .. my gut still says you need a current limiting resistor in play esp of you did not have a CC driver ...

    upload_2017-8-30_1-24-20.png

    http://ledcalc.com/#calc

    Now in theory your constant current driver should be of such a quality that it can cope with that extra ask on the current side, and your LED should be just a little dimmer with the 10 LEDS .. but everything is stacking against the math for running 10 LED's - it is a voltage drop issue. 10 x 3.6 = 36 volts. 10 x 3.8 is 38 volts supply required. - you have a max 35votls (in a cc driver it will try and up the voltage so that current stays the same)

    If your CC driver is doing the job with 8 LEDs live with that - get another driver if you need more light.

    Later Ferdie
     

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