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I ordered a variety of 3W and 5W LEDs last week based on your post, and have been testing them out in comparison to the LED strips I used for my current lights.

I'm probably going to run my system at 12 or 24V, and use adjustable (1.5-36V) buck converters to drop the voltages where needed (so I don't dump a ton of heat through a high power resistor). I think the cool whites have a forward voltage of 6-7V, which might be a little awkward for a 12V power system.

I also ordered 60-degree lenses. I think the main problem with my current lighting setup is that, although the LED strips put out 10,000 + lumens, most of the light is concentrated in the top 6-12 inches of the vivarium. This means that in order to get enough light at the substrate level, everything at the top of the tank is getting toasted. My hope with the 60-degree lenses is that I can hang the lights from the ceiling and even out the top-to-bottom light intensity. Plus, my current viv is top-opening, so having the lights out of the way will be a nice bonus.

I'll report my build and PAR findings as well. Thanks for the inspiration!
 

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D. tinctorius azureus
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Discussion Starter #23
I ordered a variety of 3W and 5W LEDs last week based on your post, and have been testing them out in comparison to the LED strips I used for my current lights.

I'm probably going to run my system at 12 or 24V, and use adjustable (1.5-36V) buck converters to drop the voltages where needed (so I don't dump a ton of heat through a high power resistor). I think the cool whites have a forward voltage of 6-7V, which might be a little awkward for a 12V power system.

I also ordered 60-degree lenses. I think the main problem with my current lighting setup is that, although the LED strips put out 10,000 + lumens, most of the light is concentrated in the top 6-12 inches of the vivarium. This means that in order to get enough light at the substrate level, everything at the top of the tank is getting toasted. My hope with the 60-degree lenses is that I can hang the lights from the ceiling and even out the top-to-bottom light intensity. Plus, my current viv is top-opening, so having the lights out of the way will be a nice bonus.

I'll report my build and PAR findings as well. Thanks for the inspiration!
Sounds like you've got a good start! Beware though that the smaller degree a lens is, the more sharp the shadows it creates, this may not be a problem and 60 isnt too bad. If your going the 12v rout, you can put two LED's with a forward voltage of 6 to 7 volts in series and get away with not needing a buck converter. However, using an adjustable one will mean you can limit the voltage going through the LEDs which will give you some control over how much light you want to output.
 

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Thanks! Each of the 6 channels use a different voltage. The meanwell drivers that I'm using are a constant current type of driver but can use a varied voltage input between 9 and 56 volts I believe. If I had done a bit more work on making sure each channel's string of LED's had a forward voltage of 24V, (this is the input voltage of the device) then I would have been able to directly wire the drivers instead of having each of them connected to a voltage converter. As it is:
Channel 1: 32.0V
Channel 2: 19.2V
Channel 3: 25.6V
Channel 4: 19.2V
Channel 5: 28.8V
Channel 6: 14.0V
Sorry if this is a super basic question... how do you determine the forward voltage for the channel? I’m assuming you connected the chips in series, and obviously the different types of chips have different forward voltages, but I’m a bit stuck at how you determine the forward voltage across the circuit based on the things I’m reading.
 

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D. tinctorius azureus
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Discussion Starter #25
Sorry if this is a super basic question... how do you determine the forward voltage for the channel? I’m assuming you connected the chips in series, and obviously the different types of chips have different forward voltages, but I’m a bit stuck at how you determine the forward voltage across the circuit based on the things I’m reading.
Yep, your correct, say I want to light 10 white LEDs that have a voltage need of 3.0V according to the manufacturer, I can string the 10 LEDs together, positive of one to the negative of the other amd end up with 3.0V x 10 LEDs and get a voltage need of 30V to run that string. Amperage will also need to be thought of when using high intensity LEDs. I'll attach a good reference chart for the voltage need for various LED color and wattage. This will just be for reference and should be checked with the specs from the manufacture of the LED.
Screenshot_20180126-215003.png
 

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Yep, your correct, say I want to light 10 white LEDs that have a voltage need of 3.0V according to the manufacturer, I can string the 10 LEDs together, positive of one to the negative of the other amd end up with 3.0V x 10 LEDs and get a voltage need of 30V to run that string. Amperage will also need to be thought of when using high intensity LEDs. I'll attach a good reference chart for the voltage need for various LED color and wattage. This will just be for reference and should be checked with the specs from the manufacture of the LED. View attachment 297234
Thanks! So then do you in some cases put multiple strings on one channel? I’m assuming maybe the 20 6K white chips were split between two strings? Thanks again - this is all really helpful info and I think is slowly starting to click in my mind, taking me back to some long-forgotten physics classes haha.
 

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Thanks! So then do you in some cases put multiple strings on one channel? I’m assuming maybe the 20 6K white chips were split between two strings? Thanks again - this is all really helpful info and I think is slowly starting to click in my mind, taking me back to some long-forgotten physics classes haha.
If you use a driver of 700mA and up to 40 volts you could do 2 strings off one driver if each led was using 350mA but each LED will have a slightly different voltage so you could overdrive some LEDs as far as I understand it.
 

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D. tinctorius azureus
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Discussion Starter #28
Thanks! So then do you in some cases put multiple strings on one channel? I’m assuming maybe the 20 6K white chips were split between two strings? Thanks again - this is all really helpful info and I think is slowly starting to click in my mind, taking me back to some long-forgotten physics classes haha.
Yeah, so most 3w LED chips have a 700mA draw so if you are putting LEDs in series (one's positive to the other's negative) then the entire string will keep the same 700mA draw no matter how many are put into series on the same string, but to help keep the voltage from needing to be so high, we can put strings in parallel. Putting LED's in parallel to each other, (one's positive to the other's positive, same thing with its negative) then the total voltage for those LED's will not increase with each set of LED's, but the amperage will increase. An example is where we can take 2 strings of 10 white LED's and put those two strings in parallel with each other. Each string has a voltage draw of 32V and an amperage draw of .7A (700mA). When we put the two strings in parallel with each other, the voltage will stay the same but the amperage will then become 1.4A (1400mA) instead of .7A. Hope this helps! Heres a crude drawing to hopefully help.
20210202_105459.jpg
 

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Yeah, so most 3w LED chips have a 700mA draw so if you are putting LEDs in series (one's positive to the other's negative) then the entire string will keep the same 700mA draw no matter how many are put into series on the same string, but to help keep the voltage from needing to be so high, we can put strings in parallel. Putting LED's in parallel to each other, (one's positive to the other's positive, same thing with its negative) then the total voltage for those LED's will not increase with each set of LED's, but the amperage will increase. An example is where we can take 2 strings of 10 white LED's and put those two strings in parallel with each other. Each string has a voltage draw of 32V and an amperage draw of .7A (700mA). When we put the two strings in parallel with each other, the voltage will stay the same but the amperage will then become 1.4A (1400mA) instead of .7A. Hope this helps! Heres a crude drawing to hopefully help.
View attachment 297246
Incredibly helpful! Thank you!
 
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