I already have an array of that LED put in a big cube of translucent acrylic with a switch that you can control the light of RGB(just on and off to produce the secondary color).
how can I dim it separate color to produce full spectrum color? (Is the way to control by the GND?)
oh...I forgot to mention that I will have a next batch..60 box of that lightBox. will be much more useful if I can use as a massive LED matrix.
please point me to the right direction.
please enlighten me!
I'm very new to the electronic scene. so sorry if I asked an stupid question.
You control it by rapidly turning it on and off, its called PWM (pulse width modulation). Are you going to have 60 of these? If so it is a very big project and I suggest you start off with 4 and see how it goes.
I think I will easier for me if they have 3+ and 1-
Yes, maybe, but they don't.
I think Mike got it in the bag there. You need to PWM the grounds (pulse width modulate the impedance on a pin), through a transistor (so you don't try to sink 12V through the arduino) and that will allow you to control the brightness. Do this for all 3 pins and you can control the colour that is mixed.
don't know exact number of current in using but you can presume it use a lot by it brightness.
Sorry but we are dealing with electronics here, that answer is not satisfactory and it does not help any advice or circuit I can offer.
From the photo I can only read one of the resistor values 130R at the top, the others are not clear.
The other thing that is a puzzle is that there are three LEDs on the module but two sets of wires labelled R, G, B, do you know why that is? Is it any pin to ground to light the LED or is it both?
Also although you say how many LEDs you are going to have you don't say how you want to control them. Do they all need to be individually controlled?
The other thing that is a puzzle is that there are three LEDs on the module but two sets of wires labelled R, G, B, do you know why that is? Is it any pin to ground to light the LED or is it both?
I was presuming that the connections are simply transfered to both sides (possibly for connecting many together in a string) although I may be wrong.
In the resistors I see 131 on the top then 301. I think the 3rd is also 131. Possibly they are RGB but that is probably wrong. Some more info is definitely needed.
More likely is that the three LEDs are RGB and in series (6 pins). On the red channel, 3 * 2.2 = 6.6, or a 5.4 volt resistor drop. With the 300 ohm resistor that would be about 18mA, close enough to a typical 20mA forward current. For the blue and green LEDs, a 3.1 forward voltage would equate to a 9.3 volt series voltage, for a 2.7 volt resistor drop, where a 130 ohm resistor would provide about 20mA forward current.
I can confirm that the LEDs are in series (bit of adjusting of levels on photoshop to see more clearly). Unfortunately, the wires are covering which resistor is for what wire (which colour) but it appears the OP has dissappeared anyway...
the result is all 3 LEDs alway glow red not blinking at all
now It's blinking!(but some kind of dimmish) just sink the ground to arduino GND pin(experimental :-[) know it's not the right way.
but it make me feel a little better that not far away to go :
Thank you!! It work!!
now I can control the brightness of that LED using PWM.
just want you to confirm that I doing it right way.
now it's like this
by using
R1 = 5K resistor
Q1 = 2N3904 transistor
change +5V to +12V external power supply
connect transistor's emitter to - of external power supply and also to the GND pin of arduino
OK 50K is too high make it 1K, and also it is not a value you can actually get, it is more likely to be 47K. There are only standard values of resistor you can buy, the most common are know as the E6 and E12 series, there is no 5K or 50 K value in them:- http://www.kpsec.freeuk.com/components/resist.htm#real
wow! so i got some rare items "non-standard resistors"
Green --> 5
Black --> 0
Orange --> multiplier of 1,000
and 5% tolerance
if I'm not wrong...
I got them come with the book I just bought yesterday.
you know uncle Mike, learning electronic by reading a book of my native language some what harder to understand and some misleading because a single word in English can translate to many words in Thai. like Voltage can translate to "[ch3588][ch3623][ch3634][ch3617][ch3605][ch3656][ch3634][ch3591][ch3624][ch3633][ch3585][ch3618][ch3660]" "[ch3649][ch3619][ch3591][ch3604][ch3633][ch3609][ch3652][ch3615][ch3615][ch3657][ch3634](that can direct translate back to electrical presure)" and they using them in non-standard way.
Thank you uncle Mike.
and Thank you everyone who wrote the tutorials on the internet.
someday I will try to pay it back to the community
[ch3586][ch3629][ch3610][ch3588][ch3640][ch3603] [ch3588][ch3619][ch3633][ch3610] (did I get that right?)
I have never seen 50K.
Would you say where you got the resistors?
(Maybe they have some other special values)
Maybe I will buy some the next time I come to Thailand.
My British friends will be puzzled
you can buy from this บริษัท อีเลคทรอนิคส์ ซอร์ซ จำกัด
they have 2 shops in ban-moh([ch3610][ch3657][ch3634][ch3609][ch3627][ch3617][ch3657][ch3629] is the largest electronic market of Thailand). not far from the grand palace.
wow! so i got some rare items "non-standard resistors"
Yes it is not often that I am surprised but now I am. In over 50 years of electronics I have NEVER seen a 50K resistor. (you didn't photo shop that did you ;))
So sorry yes you apparently can have a 50K resistor. I will now show that photo around the lab.
P.S. We will be moving our manufacturing to Thailand later this year, you never know I might get a visit.
