Ginger Viking
Well-Known Member
Long time lurker, first time posting.
Hopefully this thread may help a few others interested in making their own DIY LED light.
Last week I managed to snag two Meanwell drivers from the Tasty going out of business sale. The light I plan on building first will be based off of the HLG-120H-C500B driver that I picked up. I had originally planned on doing a COB build but after much research I have decided that a strip build better suits my needs. This will be going in a armoire(cabinet). I think the strips will be a much better choice than COBs because of the limited head space in the cabinet. I may start another thread later on the amoire build. The inside dimensions of the cab are roughly 40" wide and 20" deep. I won't know the usable height until I finish the cab.
Details of the driver so others don't have to look it up. This is a constant current driver and it supplies 500mA and the voltage range is 150-300V
The two strips that I have narrowed this build down to are the Samsung Q Series 282s and the Bridgelux Gen 2 EB Series 280s. I like the "claimed" efficiency of the Samsung but I like to cost of the Bridgelux (if Digikey's pricing is correct since they don't have stock yet). Others can verify my math but it looks like it would take 27 Q series (11V @ 450mA nominal) to max out the driver. On the other hand it will take 15 of the Gen 2 EBs (19.5V @ 350mA nominal).
Like I said I've done plenty of research but their are still a few questions that I still have lingering. The first question is on efficiency. What is the sweet spot to drive these strips? I know that I have a 500mA driver which is still above nominal for both strips selected but it is still under the max current of each. If I go with Samsung it will be wired in series because of cost but I have considered running 2 series of 15 EB strips in parallel (30 strips @ 250mA vs 15 strips @ 500mA). I like the idea of running them softer because I know I can run them closer to the canopy which gives more head room. The 30 EBs are also still cheaper than the 27 Qs but 15 EBs are way cheaper so I'm good with that too. If running them softer actually costs some efficiency then running them hard it is.
Doing the parallel thing brings another question to the table that I have seen mixed answers for and that question is what about thermal runaway? I've heard that it is not an issue with cobs and strips and I have heard that it is a problem. I've seen this argument recently on this site. Since I am looking at running two series in parallel this would be a good opportunity to use a current mirror circuit but that is a little over my head but I do have someone that can help me out with that. I also have a full on machine shop at my disposal so DIY makes sense.
The other question I had was what should I use as a heatsink. I was looking at heatsink USA 1.00" profile to mount these strips. Now they are low stock and I don't know if they will have it when I get ready to order everything. Would this be enough or would I need to go larger. I've heard a sink isn't required but what will it hurt? I'm sure I'll have a few chime in and say use u-channel but that is not as cost effective as the heatsink profile.
Last request: I don't need some douche to get on here and tell me that I need to buy a different driver or go with COBs, blah, blah, blah just wanting to hear themselves talk and make themselves feel smart. I am making a strip light with a HLG-120H-C500B driver, end of story. Anyone who mentions politics on this thread will also immediately go on mute (don't know why a "growing" forum has to dwell on politics so much that it is beyond annoying).
Oh Yeah just so you know I belong here, I know when I get finished with this light it should yield about a pound.
Hopefully this thread may help a few others interested in making their own DIY LED light.
Last week I managed to snag two Meanwell drivers from the Tasty going out of business sale. The light I plan on building first will be based off of the HLG-120H-C500B driver that I picked up. I had originally planned on doing a COB build but after much research I have decided that a strip build better suits my needs. This will be going in a armoire(cabinet). I think the strips will be a much better choice than COBs because of the limited head space in the cabinet. I may start another thread later on the amoire build. The inside dimensions of the cab are roughly 40" wide and 20" deep. I won't know the usable height until I finish the cab.
Details of the driver so others don't have to look it up. This is a constant current driver and it supplies 500mA and the voltage range is 150-300V
The two strips that I have narrowed this build down to are the Samsung Q Series 282s and the Bridgelux Gen 2 EB Series 280s. I like the "claimed" efficiency of the Samsung but I like to cost of the Bridgelux (if Digikey's pricing is correct since they don't have stock yet). Others can verify my math but it looks like it would take 27 Q series (11V @ 450mA nominal) to max out the driver. On the other hand it will take 15 of the Gen 2 EBs (19.5V @ 350mA nominal).
Like I said I've done plenty of research but their are still a few questions that I still have lingering. The first question is on efficiency. What is the sweet spot to drive these strips? I know that I have a 500mA driver which is still above nominal for both strips selected but it is still under the max current of each. If I go with Samsung it will be wired in series because of cost but I have considered running 2 series of 15 EB strips in parallel (30 strips @ 250mA vs 15 strips @ 500mA). I like the idea of running them softer because I know I can run them closer to the canopy which gives more head room. The 30 EBs are also still cheaper than the 27 Qs but 15 EBs are way cheaper so I'm good with that too. If running them softer actually costs some efficiency then running them hard it is.
Doing the parallel thing brings another question to the table that I have seen mixed answers for and that question is what about thermal runaway? I've heard that it is not an issue with cobs and strips and I have heard that it is a problem. I've seen this argument recently on this site. Since I am looking at running two series in parallel this would be a good opportunity to use a current mirror circuit but that is a little over my head but I do have someone that can help me out with that. I also have a full on machine shop at my disposal so DIY makes sense.
The other question I had was what should I use as a heatsink. I was looking at heatsink USA 1.00" profile to mount these strips. Now they are low stock and I don't know if they will have it when I get ready to order everything. Would this be enough or would I need to go larger. I've heard a sink isn't required but what will it hurt? I'm sure I'll have a few chime in and say use u-channel but that is not as cost effective as the heatsink profile.
Last request: I don't need some douche to get on here and tell me that I need to buy a different driver or go with COBs, blah, blah, blah just wanting to hear themselves talk and make themselves feel smart. I am making a strip light with a HLG-120H-C500B driver, end of story. Anyone who mentions politics on this thread will also immediately go on mute (don't know why a "growing" forum has to dwell on politics so much that it is beyond annoying).
Oh Yeah just so you know I belong here, I know when I get finished with this light it should yield about a pound.
