Array of 12 IR Leds

Projects General Guidance
1

Hello everyone, I need some help for this project,this is my first arduino project.
i'm triyng to fade up and down this array of 12 IR leds from a security cam.
There are 12v (external source).
I was wondering if there is a way to control the amount of current to brighten
up and down the leds by processing sketch or c# ????

Arduino Uno.

I allso was wondering if i take out the LDR and control it by
arduino. Is possible?????

Thank you guys for the support...

FRONT:

BACK:

2

Hi initzero,

As there appears to be some non passive surface mount components I don't think you can just bridge the LDR and fade the 12V supply up and down. Replacing the LDR with a suitable digital potentiometer (maybe http://uk.mouser.com/ProductDetail/ON-Semiconductor/CAT5132ZI-10-G/?qs=6ARB0lp6jlWjzRAgq8GoEg%3D%3D) might be the better option.

3

Thank you Riva for the replay!!!
But i don't see how to do it!!! Can you be more specific???

4

It should work if you remove the LDR and connect the V+ pin to the positive side of the LDR socket and Rw to the other. Vcc, SDA, SCL & GND will need connecting to the Arduino.
A simpler way is to measure the voltage across the LDR and if it's 5V or less then look at this tutorial http://arduino.cc/en/Tutorial/DigitalPotentiometer

5

Thank you Riva for the replay!!!
I measure the voltage across the LDR and it sets on 8.4v with full light on.
There is another way????? Maybe if i only control the amount of current of the 6.3v(strange)red and yellow wire coming from video board.

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6

Update, Ok after desolding LDR, IR leds was constant on.... That means the LDR decreses the voltage for the leds until it cuts off.... :astonished: