Thread: LED Grow Light
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Old 02-23-17, 02:19 PM   #7
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Originally Posted by jeff5may View Post

To control the brightness, the DIM pin is used. For a single board, a resistance can be connected to pull the pin low. The chip has an internal 5VDC supply that runs the current sensing circuitry and the switching output. The DIM pin is tied to this 5V reference through a 200k ohm resistor. A 250K potentiometer can be connected between the DIM pin and ground to control the brightness.
Fascinating! I think I am going to see if I can hack one of the boards and add a pot on it.

As for updates, here is the finished product:

I am pretty satisfied with the end product. Will it be overkill for growing seedlings, yes, absolutely! Will it be overkill for some DWC hydroponic lettuce growing experiments, probably not too much....but that is what experimentation is for.
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