Help changing LED's

Discussion in 'General Electronics Chat' started by daregister, Dec 11, 2013.

  1. daregister

    Thread Starter New Member

    Mar 18, 2013
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  2. tshuck

    Well-Known Member

    Oct 18, 2012
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    The datasheet you listed is for 38 different parts. Which is yours?
     
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
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    1,255
    Select R3 to drop about .65 volts at the desired LED current. So lets say you want 200 ma (.2 amps) you would use a 3.3 ohm resistor.
     
  4. daregister

    Thread Starter New Member

    Mar 18, 2013
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    0
    I am using the NTE123AP and the NTE2395 which are the equivalent mosfet and npn transistor. I also am using the green, the red, and the white LED's. I hooked up the LED's but with R1 and R3 values are confusing for me. I put a 1kohm for r1 and a 15ohm for R3. The LED's work but I was wondering how to do the math to analyze the circuit and I also put the LED's in parallel instead of in series. I think the LED's are better that way. how to increase the current through the LED's? changing R3. What does R1 do. thanks for the help
     
  5. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    Paralleling them will cause unequal brightness unless you put a small amount of resistance in series so they will share better. Select the resistor so that there is maybe 200 - 300 mV drop across it at whatever current is running through the LED.
     
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