RBG LED Voltage and Manual

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Anonymous
RBG LED Voltage and Manual 2016-01-28 18:32:02 Post No. 937536
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RBG LED Voltage and Manual Anonymous 2016-01-28 18:32:02 Post No. 937536 [Report]

/diy/ I need your help!

This is an easy one, I guess...
I recently started building circuits for fun and I am actually really bad at it, I guess.

I have got this RGB LED:
http://files.voelkner.de/175000-199999/185388-da-01-en-FULL_COLOR_RGB_LED_KLAR.pdf

And I have the following problems:

1. How am I supposed to know what colors are on which pin, with the help of this manual? The figures on the first page are showing the 6 pins, and I think pin 5 and 6 are GND. Since the LED has 2x blue and 1x red and 1x green, the 2 pins that are labeled MB are blue, I guess? And logically G stands for green? So E = red? Am I right with my assumptions? How am I supposed to know for sure?

2. In the table "Electrical / Optical Characteristics at TA=25°C" it says that the blue light needs a forward voltage of 2.0 volts. Green needs 2.2 volts and blue 3.8 volts. But there are 2 times blue? Does every blue pin need 3.8 volts, or do I need to divide by 2 (every blue pin 1.9 volts)?

3. The LED is clear. In order to see the full color spectrum, do I need to use a diffused one?

I hope you can help me with my questions!
Thanks for reading.

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Anonymous 2016-01-28 18:46:07 Post No.937540
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Anonymous 2016-01-28 18:46:07 Post No.937540 [Report]

blue pins need 3.8v each
the chips inside should be close enough that it will look pretty white but if you look closely you might be able to pick out the individual chips
everything else is correct
e is probably efficient red or something.
the wavelength chart confirms mb and g are common sense.

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Anonymous 2016-01-28 19:52:34 Post No.937572
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Anonymous 2016-01-28 19:52:34 Post No.937572 [Report]

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>>937536
Found a better datasheet with readable pin out.

http://docs-europe.electrocomponents.com/webdocs/1384/0900766b81384fe2.pdf

Some calculated resistor values to use with a 5v supply @ 15mA per LED
red = 200 ohm
green = 180 ohm
blue = 68 ohm

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Anonymous 2016-01-28 20:04:09 Post No.937581
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Anonymous 2016-01-28 20:04:09 Post No.937581 [Report]

>>937540
>>937572
Thanks a lot!
This was very helpful.

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Anonymous 2016-01-28 20:19:32 Post No.937586
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Anonymous 2016-01-28 20:19:32 Post No.937586 [Report]

>>937572
But wait, how did you calculate the values for green and blue?
(5-3.8) / 0,015 = 80 ohm
(5-2.2) / 0,015 = 187 ohm
And why 15mA?
In the sheet it says 20mA. What am I missing?

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Anonymous 2016-01-28 20:28:55 Post No.937590
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Anonymous 2016-01-28 20:28:55 Post No.937590 [Report]

>>937586
The forward voltages given in that RS datasheet were a little different.

20mA is the maximum continues allowable LED current, but its common practice to run them at slightly lower than that for long life. LED's dim over time and this is accelerated at higher currents, but if you really wanted the maximum brightness out of them then go for 20mA.

I use the desktop version of this calculator for calculating LED resistors http://www.electronics2000.co.uk/calc/led-series-resistor-calculator.php use the "Calculate Resistor Value from Vf and If:" option.