Lighting DIY Mars to Cree Cob conversion

[DamnSonDanson]

Hey I need some help if anyone can provide it. Here's the story:

I modded a Mars Reflector 96 with six CXB2530s, two in series per 55w driver, and it works amazingly well. It draws 136w from the wall which is the number I'd expect (6 cobs and 2 fans), no problems there. But I did the same upgrade on two more Mars 96 units and both of them turned out far brighter and are pulling around 350w from the wall with the same amount of lights and fans, and putting out a lot more heat as well. This concerns me.
The drivers in these two (the revision with 5w LEDs) are different to the ones in the first mars (which had 3w LEDs) but the output ratings are roughly the same according to the stickers (50-86v, 0.6a/0.665a), although they seem to be running at least twice that because the current meter is measuring a 1.4a draw and more than double the wattage of the first unit.

Are these just incorrectly labelled drivers, or have I done something wrong? All three of the Reflector 96 have been wired identically and use the same CXB2530s, the drivers being the only difference. What's the best way to lower this output? I want the chips to be running at lower wattage for better efficiency and heat management.

Thanks.

 

[BigSm0]

Luckily you did read the drivers and didn't go into it blind. I'd hate to give out suggestions besides not using it since the drivers seem to be listed wrong. But it it were me I would test each driver separately and make sure that they are all the same first, if you figure the draw from one driver and the others seem to be the same then wiring them in parallel could be an option. Series wiring uses the same amperage to run the cobs but subtracts the voltage of additional cobs. Parallel wiring uses the same voltage but subtracts the amperage. So it it indeed is a 1.4a driver 2 cobs would put 700ma to each cob.
3 cobs on that driver in parallel would put 466ma to each cob, while all of these options would only draw 36v still.

This is sort of a dangerous problem to have so make sure you do your best to protect yourself.

 

[DamnSonDanson]

Luckily you did read the drivers and didn't go into it blind. I'd hate to give out suggestions besides not using it since the drivers seem to be listed wrong. But it it were me I would test each driver separately and make sure that they are all the same first, if you figure the draw from one driver and the others seem to be the same then wiring them in parallel could be an option. Series wiring uses the same amperage to run the cobs but subtracts the voltage of additional cobs. Parallel wiring uses the same voltage but subtracts the amperage. So it it indeed is a 1.4a driver 2 cobs would put 700ma to each cob.
3 cobs on that driver in parallel would put 466ma to each cob, while all of these options would only draw 36v still.

This is sort of a dangerous problem to have so make sure you do your best to protect yourself.

Yes, safety is paramount. The whole thing seems to still be running OK, just have 4 of the 6 cobs turned on, heat is manageable and it's still super bright, but I'd still like to know what's going on and wire it to use lower wattage if possible.

Assuming at least some of the label is correct and they operate between 50v-86v, am I even able to run the chips in paralell given that the forward voltage is only 36v? I'm still pretty green regarding this side of electronics so I might be missing something.

 

[BigSm0]

The voltage will still be below the max driver output. Parallel divideds the current. If your cobs are running at 50w each running them in paralell will still pull 36v total and 25w each. That's the only way to solve this issue besided buying new drivers.

 

[DamnSonDanson]

This issue solved itself, must have been the power meter we were using, today they both came up as ~160w 0.7a which is what I expected and we couldn't replicate the higher reading. False alarm, don't trust cheap power meters is the moral I am taking away from this.

 

[TreyDogg]

I have a mars 300 it gets to hot for my 2x2. I would like to use this mars to maximise mainly bloom for my 2x2. I would like any advice on what to buy. I'm pretty basic on knowledge in this area. I have seen the posts and I think the 4500 is what is sugested? Currently the tent is running a mars 48. Some say eBay has bad chips can you let me know where to get the chips if not eBay?

 

[BigSm0]

I have a mars 300 it gets to hot for my 2x2. I would like to use this mars to maximise mainly bloom for my 2x2. I would like any advice on what to buy. I'm pretty basic on knowledge in this area. I have seen the posts and I think the 4500 is what is sugested? Currently the tent is running a mars 48. Some say eBay has bad chips can you let me know where to get the chips if not eBay?

Northern grow lights and cobkits.com has all you need. Citizen for price and performance is the best way to go.

 

[TreyDogg]

The prices are real good. Saw the reflectors on cob kits can that be added to a diy on a mars 300? I know I only have a 2x2 but would like to get the most out of this light If I make it.

 

[BigSm0]

Head over to the DIY section. There is a lot of info there that can help the future hackers out. I may even buy a mars and do a thorough step by step for everyone. 20% efficient epistar LEDs are the cheapest diodes sold. Cobs are 50- to even 60% efficient. Photons to heat ratio. Bold claims from led companies suck people in and most are false.

 

[bastovan20]

hello people,my friend is helping me to build my diy cob light with citizen 1212,clue 048.
he is amazed with they low price and quality.

he has some mars hydro II 1200 panel,it draws around 500w from the wall.
he was thinking of upgrading it with cob and get better efficency,lumen etc..

what cobs and number of them do yo recomande for mars 1200?
covering 4x4 foot space..

but cree are to expensive..citizen or vero would be nice?
he is also planning to put better fans,quieter ones and better ones..
thank you