Thread: LED Grow Light
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Old 02-23-17, 09:51 AM   #6
jeff5may
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The regulator boards you have look just the same as what I put in the truck. The typical circuits look like this:

The chip comes in 2 different packages:

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.

To control multiple boards, you can feed them a common PWM signal to make them all behave the same. It would be easy to construct using a 555 timer ic and a few parts. I'm sure if you looked around on the web, another dirt cheap board could be found that could be wired straight to the DIM pin to supply a PWM signal.

Last edited by jeff5may; 02-23-17 at 11:38 PM.. Reason: more info
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