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Originally Posted by mseepman
Any new developments on this Mike?
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Well, sort of. Still waiting for more heatsink/fans as well as Blue LEDs as per my previous post. Somewhat rethinking the resistor method of controlling current to each LED so I've also ordered ten 12VDC constant current drivers to see how that will work. It may be more efficient than resistors but the downside is, they are somewhat larger than a 5 or 10 watt resistor & they also cost a bit more. These constant current drivers will accept an input of 12 to 24VDC and provide constant current of 800-1000mA at 8-12VDC out. As with the resistors, the plan is to use one per LED.
One idea I considered was to use 3 low resistance, high wattage resistors, one on each of the 12VDC power supply outputs feeding 3 different colours of LED. Not that keen on that idea since these resistors are physically quite large & if one goes bad, I risk frying all the LEDs downstream of that. So I'll probably stick with a resistor or driver for each LED. This will provide a safety factor & also allow me to tune each LED individually. However, not finished yet, & I've also ordered three 12VDC, 8A LED strip light brightness controllers. Might use them in combination with the resistor/drivers. I'll open one of these up to see what's inside when they arrive. Curious to see whether it's just a potentiometer or if there's some electronic wizardry going on in there. My 10watt LEDs are bulk ordered & not binned so production variations will require slight differences of current to each LED for the desired light output. I don't have a PAR meter to measure light output, but at least I can tune each LED to draw at or below the rated maximum.
Going shopping this afternoon for either plywood or thin pine planks to build some sort of enclosure to hold the rails. Would like to keep it open, so I'm thinking some wide side pieces as a frame & a few along the top to mount the terminal boards, resistors/drivers as well as keep the wiring neat. I'd really like to keep the weight of the whole thing down.
I've seen a few similar builds now on RC, one where the chap is using the larger 50watt LEDs. The build looks amazing but much more involved than mine since he needs to cool each LED chip with this monster heatsink with liquid cooling & huge fan. Since the higher wattage LEDs generally need higher voltage (36 VDC), your choice in power supplies gets limited & you end up having to buy the ready made drivers for whatever wattage LED you intend to use. One of the things I prefer about my build, is that 12VDC power supplies & drivers are more common. I can also diversify a bit easier with the colour spectrum & if a LED goes bad, I'm not out as many $$s as with the larger ones.