LED UFO dimming advice?

Triplec

Triplec

Well-Known Member
Anyone have experience with dimming LED UFO's? I am having some light burn issues because of the light being too close. With my current setup, which is a cabinet I built I have no options to raise the light or lower the plant - as the light is at the top and the plant is at the bottom. So I figured I could try dimming the light slightly to decrease the stress. I have an Apollo 135w UFO, link below.
I was thinking of getting a 300w plugin dimmer from Home Depot, but don't want to mess up my light. I've emailed the manufacturer to see what they suggest but have not heard back yet. I could make my own dimmer, but curious is the plug in one would work.

Light http://www.apollohorticulture.com/LED-ufo-135w.html

Plug in dimmer http://m.homedepot.com/p/Lutron-Credenza-300-Watt-Plug-In-Lamp-Dimmer-White-TT-300H-WH/100001525/
 
D

deadgro

Well-Known Member
Unless your buds are bleaching (turning white), the issue is heat, not light. Increase airflow or get AC. I wouldn't mess with the light.

With LEDs, I believe you need to dim on the DC side, not the AC side. Someone more knowledgeable can correct me if I'm wrong.
 
Triplec

Triplec

Well-Known Member
deadgro said:
Unless your buds are bleaching (turning white), the issue is heat, not light. Increase airflow or get AC. I wouldn't mess with the light.

With LEDs, I believe you need to dim on the DC side, not the AC side. Someone more knowledgeable can correct me if I'm wrong.
Click to expand...
You could be right, but my research says light burn. It's only occurring with the tops in the middle of the plant and closest to the light. The other tops are maybe an inch or two lower and don't show signs of stress. I did bend/LST what I could in the middle. Maybe that will help. I will look into he DC/AC cause I have no idea. I definitely don't want to blow a light.
 
Triplec

Triplec

Well-Known Member
I tired the plugin dimmer switch and it light was making a quite loud buzzing sounds. Doesn't look like that will work. Not sure if I can build a switch that would work on not.
 
rkymtnman

rkymtnman

Well-Known Member
how close is the light to the plant tops?

and deadgro is correct. dimming that thing wont be easy as a dimmer switch.
 
Abiqua

Abiqua

Well-Known Member
Dimmers you are using are Constant Voltage from AC current....UFO's take AC and convert it to DC constant Current and that is why it won't work.....setting the voltage will fry the diode...you have to use a PMW signal to "dim" CC drivers....

UFO's don't have that kind of circuitry, you would have to replace the AC/DC driver at the very least....
 
Triplec

Triplec

Well-Known Member
Abiqua said:
Dimmers you are using are Constant Voltage from AC current....UFO's take AC and convert it to DC constant Current and that is why it won't work.....setting the voltage will fry the diode...you have to use a PMW signal to "dim" CC drivers....

UFO's don't have that kind of circuitry, you would have to replace the AC/DC driver at the very least....
Click to expand...
Alright, thanks for the info man.
rkymtnman said:
how close is the light to the plant tops?

and deadgro is correct. dimming that thing wont be easy as a dimmer switch.
Click to expand...
The middle is what's affected. Those tops are about 4 inches from the light. Recommend distanced is 6-8 in.
 
Triplec

Triplec

Well-Known Member
I'm just going to try LST then some more and hope all goes well. I hate to do that in 4th week of flower.
 
rkymtnman

rkymtnman

Well-Known Member
i had one of those 3 Watt UFO's and I could keep it almost on top of the plant (2 inches away) and never burned anything.

you sure it's not heat, pH, ppm related?

you could always put small pieces of tape over a few of the LED's to reduce some brightness IF you are sure it's light related problem
 
Triplec

Triplec

Well-Known Member
rkymtnman said:
i had one of those 3 Watt UFO's and I could keep it almost on top of the plant (2 inches away) and never burned anything.

you sure it's not heat, pH, ppm related?

you could always put small pieces of tape over a few of the LED's to reduce some brightness IF you are sure it's light related problem
Click to expand...
It could be I suppose but I'll post a pic when the lights kick on in an hour or so. Before I LST'd some of the tops in the middle last night you could see a circle of yellow leaves in the middle of the plant and the upper most top leaves purple vein stuff described in the light problems section of growweedeasy.com. I haven't checked the buds to see if there's any bleaching but will here in a few.
 

Attachments

Triplec

Triplec

Well-Known Member
She's looking a little rough tonight. Much more yellow overall. I guess there could be a deficnacy. But the second pic you can see the leaves where I thought it was light burn.
 

Attachments

robincnn

robincnn

Well-Known Member
A [QUOTE="Hgrow said:
Anyone used this UFO ?http://www.ecosunlite.com/e_productshow/?23-Par-LED-Grow-light-23.html
Click to expand...
I wonder how much are those for with Cree LED. I have used a similar UFO with secondary optics.
http://www.ebay.com/itm/9-Bands-Secondary-Lens-45x3-watts-High-Power-LED-Grow-Light-IR-UV-Aurora-UFO-X-/181604280705?

The LED drivers generally have an input range of 100-240 volts. So attaching the dimmer on power socket AC side will not work.
You can swap power supplies for low current once. Another way.. Most UFO have 2 circuits and 2 power supplies. if u connect the 2 circuits within UFO to a single power supply in parallel. Then you will get half the power. I would just move the plant
 
Hgrow

Hgrow

Active Member
robincnn said:
I wonder how much are those for with Cree LED. I have used a similar UFO with secondary optics.
http://www.ebay.com/itm/9-Bands-Secondary-Lens-45x3-watts-High-Power-LED-Grow-Light-IR-UV-Aurora-UFO-X-/181604280705?

The LED drivers generally have an input range of 100-240 volts. So attaching the dimmer on power socket AC side will not work.
You can swap power supplies for low current once. Another way.. Most UFO have 2 circuits and 2 power supplies. if u connect the 2 circuits within UFO to a single power supply in parallel. Then you will get half the power. I would just move the plant
Click to expand...
You can quote from their website with Cree LED ,these two are similar . I wonder how's the inside cooling system , they post their inside cooling system , seems good .
You mean the cost of their Cree LED ??http://www.ecosunlite.com/e_productshow/?48-CREE-XPE-LED-48.html
 
You must log in or register to reply here.
Top