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Topic: Need Help COB LED 10W 12V .. (Read 313 times) previous topic - next topic

Elanordir

Dec 08, 2018, 05:30 pm Last Edit: Dec 08, 2018, 05:33 pm by Elanordir
so i just brought some COB LED to make it into Flashlight , but the thing is , it wont turn on easly , i tried using Arduino just by the 5V and GND and it shine little bit , but when i try using battery case 4x2 (i dont know what its name) using 8 x 1,5V Battery on it, in wont light up not even little bit .

Somebody..

am i missing something here?..

Oh yeah and i also tried to SMD LED , and it fried 3/4 of them , so that indicate High Voltage? (i dunno)

this is the LED


Grumpy_Mike

#1
Dec 09, 2018, 10:43 am Last Edit: Dec 09, 2018, 10:44 am by Grumpy_Mike
Quote
i also tried to SMD LED , and it fried 3/4 of them
What does this mean?
When you say "to SMD LED" it sounds like SMD is something you do to an LED where as SMD is a description of an LED standing for Surface Mount Device. If by "to" you mean "two" then how can you fry 3/4 of two LEDs.


Quote
i tried using Arduino just by the 5V and GND and it shine little bit
How was the Arduino powered? If through the USB then there is a thermal fuse that limits the current through the LED.

Quote
but when i try using battery case 4x2 (i dont know what its name) using 8 x 1,5V Battery on it, in wont light up not even little bit .
So what was the voltage out of the battery when you measure it without a load and with the LED connected.
And also what type of batteries did you use.

Connecting an LED like this to batteries is a bad idea because the current limit depends on the battery chemistry, you have no control over it.  

Elanordir

#2
Dec 09, 2018, 12:33 pm Last Edit: Dec 09, 2018, 03:37 pm by Elanordir
SMD LED I mean this ,


the Arduino is powered using USB from my Laptop and the 5V and GND through BreadBoard then go through the COB LED

i use Alkaline Battery

and i mean i use 8x 1,5V Battery , i mean a direct eletricity , not through Arduino then> LED COB,
But when use Arduino , i only power it up using Laptop USB Port like this

Laptop > Arduino > Breadboard > LED COB

And when using battery , it's like this..

8x1,5V Alkaline Battery > LED COB


i kinda forgot what to use , because its been 2 years im not playing the Arduino and making stuff my self and experiment , so i kinda not sure (kinda forgot) what is the purpose of Transistor or Capacitor and how to use it , other than that i still had some knowledge of it

except for controlling output and input , i dont know what to use

Grumpy_Mike

You need a resistor as a current limiting device in every LED. Circuit for LEDs that draw undear 40mA or so.
For LEDs that draw more you need a constant current driver to ensure that the current is under control.
Look up constant current drivers on Google.

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