want to build some LEDs need help please :)

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Prawn Connery
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want to build some LEDs need help please :)

Post by Prawn Connery »

It's pretty easy once you know what to look for. You want to reference the Forward Current vs Forward Voltage graph on the LED spec sheet, like the one below. This will show you the relationship between voltage and current, which you can multiply against each other to work out the wattage or power requirement.
Screen Shot 2021-03-14 at 9.35.46 am.png
For example, on the 560mm graph above you can see that at the maximum Forward Current of 1400mA (1.4A), the Forward Voltage is 20.5V. Multiply these two figures together and you get a maximum power of 28.7W (1.4A X 20.5V = 28.7W).

You can do this with any LED strip.

These graphs will also tell you what sort of driver you need, because you can reference the voltage graph to see how it changes with current and work out whether your driver will suit. For example, the maximum voltage of the 1120mm strip is 41V at 1400mA (1.4A) – so a 42V driver is what you want to run each strip at 57.4W.

However, you could also use a 40V driver if you only wanted to run each strip at 1050mA (1.05A) = 42W per strip, as you can see the 40V requirement intersects with the 1050mA line.

With the correct voltage driver, all you need to do is add up the number of strips you need to suit a particular power rating: a HLG-185H-42A driver would power a minimum 7x 560mm strips.

I get this figure by dividing 185W from the driver by 28.7W maximum for each strip = 6.44. You ALWAYS round up to the nearest whole strip = 7. If you round down to 6 strips, then the driver can overpower each strip: 185W divided by 6 strips = 30.8W, which exceeds the maximum power rating of the 560mm Bridgelux strip.

7 strips will not reach full power (185/7= 26.4W) but will be close enough without exceeding specs. In reality, that 185W driver will put out more than 185W (Mean Well drivers – except the B type drivers – always exceed their rated power output), so you will likely get maximum power out of each strip. So then you might think to add another strip = 8x strips to provide a buffer.

It is always better to under-drive your strips than to run them near maximum output. They will run cooler and more efficient and will last longer.
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Prawn Connery
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want to build some LEDs need help please :)

Post by Prawn Connery »

Personally, I like Samsung strips – especially the F Series double-row LED strips. These are all frames that I have built.
FSeriesFrame.jpg
FSeriesFrameLit.jpg
FSeriesFour.jpg
HSeriesFrames.jpg
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