The far red thread

grotbags

grotbags

Well-Known Member
Randomblame said:
Yepp! That's all correct, bro!
But at 1,3-1,5amps the voltage is already higher like 22,3v with 1000mA. In the moment the voltage reach the CV area(vol. adjust. range on A version drivers) the driver would switch in CV mode.
But with a series-parallel setup it really don't matters which mode is used, the maximum current each string gets is simply not high enough to damage the diodes. The voltage/resistance differences between modern LED modules are really small (less than 0,1v) so with strings of 2 strips the voltage of each string should be pretty much the same.
This also reduces the risk to get thermal runaways but make sure they all use the same type of heat sink and run with the same case temps. When you can feel temp differences between the strip heatsinks that's an indication for thermal runaways but it would also be visible because the hottest strips would get more current and would shine brighter.

B type driver also switch to CC mode if the voltage fells off of the "CV area" but it's not a problem with the strip setup. For B-type drivers the point is not exactly mentioned but as soon as he can deliver all of its current and the voltage is below 48v he should use CC mode. At first he would try to use its constant 48v but with 48v the strips would run with 1,6A(the 25v in the datasheet is absolut maximum, not the voltage at max. current). The used bin would use around 3v at 200mA so at 24v you already see 1,6A. But for your setup the driver has not enough current(each string gets only ~1,5A). Now the driver is again forced to apply ~47V and he should switch in CC mode.
With the A-type driver this range is only a bit wider because of the adjustable voltage range but B type has no voltage regulator. For this reason they switch earlier into CC mode.

Only with a single string that could be an issue but only when the driver has enough current to damage the diodes.
Lets say you have 10 cheap ebay full spectrum 3w diodes, 33v @700mA and you use an HLG-40H-36A or B.
With A-type you could reduce the voltage to 33v and because voltage limits current flow the string would run with ~700mA.
With B-type the diodes would get probably 35v and the full current of the driver and the diodes would die because of overheating.To make sure the diodes/driver run in CC mode, its dimmable and does not create overheating you need to take the HLG-40H-42, 48 or 54A or B. The driver can not apply the CV mode and for this reason he would run in CC mode. With the 42v version (980mA) its still enough to damage the diodes but you can dimm them down a bit. 48v version has still 0,83A.. still too much but 54v has only 740mA and this fits with this type of diodes. So 33,2v maybe and ~750mA max.

With Osram Oslons or XP-E/E2's in far-red 1A is maximum current and the 42v version is the best fitting driver if you plan to run them near or slightly above max. current.
The 48v version has "only" ~830mA from datasheet but can probably go to ~900mA. So there would be still a bit of head room and its perfectly safe to use the driver this way.
For all this reasons I've recommemded the HLG-40H-48B to drive your string from13 far-reds. With 900mA they would use 2,2-2,3v each so maybe 30v for the whole string, that's ~27w net and 30-31w at the wall
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brilliant thankyou @Randomblame, good to know im on the right track.

i plan on using B version drivers because i want remote dimming of all channels. i have read about the A version of the CV drivers giving slightly higher max current than what is listed on the spec sheet is that not the case with the B version of the CV driver? or is it only higher when you max out the vo pot on the A version?.

i based my "per strip mah" on the numbers in the 'current adjust max (reported)' column here- http://ledgardener.com/mw-cv-driver-ref/.
are the max figures the A version with both pots maxed?, will the B version only make '(spec)' numbers?.
 
Randomblame

Randomblame

Well-Known Member
grotbags said:
brilliant thankyou @Randomblame, good to know im on the right track.

i plan on using B version drivers because i want remote dimming of all channels. i have read about the A version of the CV drivers giving slightly higher max current than what is listed on the spec sheet is that not the case with the B version of the CV driver? or is it only higher when you max out the vo pot on the A version?.

i based my "per strip mah" on the numbers in the 'current adjust max (reported)' column here- http://ledgardener.com/mw-cv-driver-ref/.
are the max figures the A version with both pots maxed?, will the B version only make '(spec)' numbers?.
Click to expand...

Nope, all MW HLG drivers can have up to 108%. There are test reports on Meanwells website for each driver. Only make sure the poti's have 110k to make use of its 108% without switching the dimmers off.
Simply solder a 10 or 20k resistor to the middle prong of the dimmer if you don't find siutable ones. The cheap B100k potentiometer have a pretty wide range and can have between 85 and 115k so the best thing is you test their resistance (fully turned open) with a multimeter.(left and middle prong = dimming clockwise to turn it up)

If you look at the datasheet at the dimming methods page and have a closer look at resistance dimming you can see that you'll get 80% output with 80k, 90% with 90k, 100% with 100k and to get the full 108% you need 108k.

You could use a better dimmer the one from rapidled for instance(6$). It works with 0-10v and use the 10μA of the dimming circuit. With 0-10v or PWM dimming there is no such limitation but therefor its the cheapest solution. A 10pack B100k dimmers you can find for ~3$ on e3ay.
 
A

All-in

Member
I am also wanting to introduce some near infrared 730nm. I can only find 850nm alone or 660. Will 850nm have similar or same affects as 730nm? Or does anyone have a link to a light on a budget that would do? I have 4 plants in a 5×4.5 grow room with 8ft cieling. Any help would be greatly appreciated. I failed to mention im not super tech say so building a light is out for me. Im more of a plug and play or at least some good assembly instructions. Thanks Axion42 I tried to reply but to new to this forum.
 
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Axion42

Axion42

Well-Known Member
I ran it during lights on and also 10 minutes after lights went out for EoD. Hard to say how it went, I had no runs to compare to since all my lights, and rdwc system was all new to me on that run and I had a bad infestation of thrips in flower, they deffinetely hurt my harvest. Thrips are all gone and I'm vegging for 2 more weeks before I flip again. Plan to run the far reds during lights on as well as 5-10 minutes after.
 
Mikenike

Mikenike

Well-Known Member
Axion42 said:
I ran it during lights on and also 10 minutes after lights went out for EoD. Hard to say how it went, I had no runs to compare to since all my lights, and rdwc system was all new to me on that run and I had a bad infestation of thrips in flower, they deffinetely hurt my harvest. Thrips are all gone and I'm vegging for 2 more weeks before I flip again. Plan to run the far reds during lights on as well as 5-10 minutes after.
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Oh sorry to hear man. What kind of driver/power supply you use? I’ve got 4 of these but have a 4x8 now instead of my old 4x4. Got a 20w driver for all 4 but I don’t think that will be enough. Aiming for only EoD
 
Axion42

Axion42

Well-Known Member
20w should be enough. I use 10watts for a 4x4, it doesn't take much for the EoD to take effect. I'll have to check what driver I used later.
 
Airwalker16

Airwalker16

Well-Known Member
Mikenike said:
You using these for EoD treatment? What driver did you use for both and how’s it going so far?
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If using 3 boards, meanwell LPV-20-5 will work literally perfect in parallel.


Use the selection menu to choose 20w and 5V.

Or if using 3 in series, to APC-25-1050 is a great fit, too. but I'd recommend you get the APC-35-1050 just in case you want to add another board. it will still work perfectly with 3 as well as 4.
These would be wired IN SERIES.

 
Airwalker16

Airwalker16

Well-Known Member
And in case you didn't know, the far red board page on HLG website has driver options at the bottom of the page. Just saying FYI. Looks like they run at 700MA though.
But that's a huge board for 3 diodes. I can guarantee they can handle 1000-1050MA easy.
 
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C

ChrispyCritter

Well-Known Member
Hi! My first post after lurking for years. I read tons about far red four or five years ago and knew it was something I wanted to incorporate into my organic soil and led light grow but at the time far red led weren't readily available to a dude like me who didn't know anything about anything. So I was using my Tasty led but wwanted to add another so I went with Timber. In the process of buying it I asked a bout far red 730 nm and they said sure what size. I said whatever fits in the other box with my light . I thought it was a good price and they built it so I had the light. Now the timer for end of day for 10 minutes. At the time people were trying to figure a way to do the regular lights and then the far red too using raspberry pi setups that are way over my head. I had what I needed the whole time. Sentinel light timer with recycle timer for hydroponic feedings or whatever built in. it even had a photocell so my red light turns on when other lights shut off. Perfect. Only issue is mine was older so the digital numbers are red so I tape over them so not to hermie my plants. I dropped a few names in there and even though it's my first post in not spamming. Just trying to say what worked for me and hope it helps people.
 
JavaCo

JavaCo

Well-Known Member
Not sure if the far red did it but she went purple on me the areas with the least far red stayed green a lot longer than the buds under the far red, they went purple right away. Running 10% far red like the video suggests.These are day 49 flower photos might just be ready next week loving this strain. 1120191703f.jpg1120191936f.jpg1120191935a.jpg
 
Airwalker16

Airwalker16

Well-Known Member
A

All-in

Member
I have questions, Im a newbie so please be patient. I have 2 California lightworks solar system 550's and their far red light It is 100w. I also have the controler. The question is when I conect the Far red light to the solar system controlor it is on the same time as the lights, is this normal? I thought you only used the far red at end of day and for a short time after lights out. Ill be gald to answer any questions.
 
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