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Old 03-15-2013, 04:25 PM
ScubaSteve ScubaSteve is offline
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Quote:
Originally Posted by reefme View Post
Planning to use mosfet, but Meanwell LDD driver is better. Can some one show me how to wire this? Does it requires any resistors?
The mosfet approach is a lot more difficult to implement, even if you know what you are doing. The LDDs work basically in the same way but have a much more efficient switching scheme and run a lot cooler (not to mention added thermal and overcurrent protection). The schematic Dom showed you is correct and, yes, the LEDs are backwards. I was in a rush when I drew that up. The resistor connecting the PWM pin is optional but is there to cause the fixture to fail off in case the driver becomes disconnected from the controller. Without this it fails to 100% on. Not the end of the the world, but the pull-down resistor is more rigorous in terms of design.

Vin-, the ground/negative of the controller and the ground of the power supply are all connected together. If not, you get funny behaviors like the LEDs operating at 50% max output and fried drivers. Don't ask how is figured this out.
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