Samsung LM561C Flexible Strips

[ledtime]

Good morning everyone!

I'm really trying to design some lights and need some help, please. I really like how Lapides built his Spyder type light using flexible Samsung LM561C strips. He uses 24V, 60 diodes per meter, S6 bin, 4000k spectrum.

The guy he bought them from says he makes them in 20W per meter up to 36W per meter. I have no idea what Lapides used. What's the benefit of having a higher wattage per meter with the same number of diodes? I take it that it's running a higher current through then therefore pushing them harder? It would seem that would be good for efficiency if running them at 75% power? This way you could get more lumens per watt in the same footprint with fewer rails on the light?

I'm also still having trouble understanding how to pair a driver with these strips. He did 14, 4 ft lengths with those lengths wired in parallel tied to a constant current mean well. That means that the current draw of one 4ft length is the calculation needed to determine max current of the entire light?

Any help with ask of these questions would be really, really appreciated. Thank you all in advance.

 

[brickweeder]

...I'm also still having trouble understanding how to pair a driver with these strips. He did 14, 4 ft lengths with those lengths wired in parallel tied to a constant current mean well. That means that the current draw of one 4ft length is the calculation needed to determine max current of the entire light?

They sell the strips at digikey, do a search for F-Series Gen3.

As for pairing the strips with drivers, you should spend an hour reading about ohms law and looking at some series and parallel circuits. Equate the the resistors in the sample circuits to the LED strips or cobs (as far a voltage drops are concerned), and equate the voltage source in the sample circuits to the LED driver output. Make sure you understand voltage drops and how current splits depending on the circuit design. Break out the pencil, paper, and calculator and do the voltage and current math. Maybe 2 hours instead of 1. If you do this, you'll be able to answer your own question every time you want to make a change to your lighting system, or deciding what to purchase.

But if you just want the quick answer, then for a parallel circuit, you sum the currents of each leg and add them up. The total current is your driver size. So if you have 5 strips in parallel and you want 1 amp to flow through each, then your driver output should be 5 amps. Keep in mind with this parallel setup example, if one strip fails, then the 5 amps is split between 4 legs, for 1.25 amps each. So you should consider your strips max current rating, and set your operations up so that if you get a strip failure, the new current splits will not exceed your strips max rating, or you risk burning out all your remaining strips or shortening their lifespan (only in parallel circuits).

You should also sketch out a series circuit or a combo parallel-series circuit and compare them and the component prices to see if you want to go that route instead. Good luck and enjoy your build.

 

[Lapides]

The ones I got are 20 watts per meter.


It probably has something to do with the resistors or whatever they have built onto the strip.


I didn't get a choice when I ordered if I remember correctly.


I really don't know the difference but I feel I would want to draw less watts per meter anyway.


These diodes perform with better efficacy when run softer. That's why I tried to incorporate as many diodes in my given space as I could.


Time to go update my thread with these details.

 

[f-e]

I would be looking at the 36w per meter, expecting more of the same diodes, spaced closer together. If you placed 10 of these, side by side, at 100mm centers, that is only 360w per meter. Personally, I'm at 600w per meter. 600w at 36w a strip, is 17 strips 59mm apart. Try and do 600w per meter with 20w strips, and each strip has 33mm of real-estate to live in. So if you settled for 400w a meter, it's a 20w strip every couple of inches. Which would be a lot of work for maybe 500 ppfd.

The 36w per meter limit, is a thermal one. They are getting too energy dense. They might even need heatsinks. Which I hope could be U channel, or the cost will be prohibitive.

 

[ledtime]

Thank you guys so very much for giving me that info to work with. I've read and read and sourced and priced.

After it all I found that I couldn't build the light I wanted for cheaper than I could buy it for. (I love building things myself, stay tuned for my grow box build).

Here is what I ordered: https://app.alibaba.com/dynamiclink...share_detail&ck=share_detail&shareScene=buyer

It's a 600w version of Lapides light but made with LM301B boards that have some Cree 660nm worked in. I'm going to cut the mounting channel in half and stuff this baby in a 2'x4'x4' box running it at about 70%. 480w ish? Should rock out for my SOG grow. I've always been fascinated with Dr. Buds SOG with CFL's. I'm going to do it with LED and coco. Should be a ton of fun.

What do you guys think of the light?

 

[Douglas.Curtis]