DiY LEDs - How to Power Them

anarchist59

Member
I am using 70 volts cree cxa3590
With 2 in series. You have 140 volt
With an old seperate transformer. Rectified you have. 115ac x 1.4 = 161 volts dc

Thats a good basis to build a constant current source
All you need is an op lm358 a reference lm339 power transistor with heat sink
A few resistors and caps thats it.
It is more stable than the meanwhile stuff
 
Quick stupid question here, what is the math for running a cob? Say i have a 50W Cob and want to run it a 1.4A how do you calculate how many watts its going to put out in order to match it to the driver? I know its something stupid simply that i am missing here and hate to even ask because i knew it and just forgot over time.
 

Shinsou

Member
Hi guys, was wondering if there were any tests on efficiency when running drivers to the max.
For instance I have a fixture with 4x 3590's run by a HLG-185H-C.
Now most people selling them say they consume 200-220w.
But when I crank the dimmer on the driver to the max it pulls 242w from the wall.
The light intensity increases significantly (at least visually) feels like 15% brighter compared to 220w.

Sadly I dont have any light measuring instruments so I was wondering if someone had tested it out and how much more light you get and how much worse the efficiency gets..
 

Chech

Member
I did this & then touched the wires together to see if it worked...
A tiny little spark on the wires i touched occured then the 4 x cobs lit up...
The the first two went out and the other 2 stayed lit...
This all happend within a split second
Did i fuck my cobs?



-Do not apply AC power to a driver that is not connected to an LED string
 

Braman

Well-Known Member
Could some one explain me, how is efficency calculated.. that for example cxb 3590 36V is more efficient @ 1400ma or 1000ma than it is @ 2000ma. Can that information be found in datasheet or somewhere?
 

Braman

Well-Known Member
I am looking at Meanwell driver - HLG-185H-C700A. Can i RUN just one 36V COB with this? As I understand COB will "eat" voltage as much as it needs and driver will give just 700 ma?
I mean if the min V is higher that 36V, I cannot use it for 36V COB?

Or i should just ask - what driver is suitable to run 1x 36V COB?

edit:
Just foun a driver LPV-35-36. This would be perfect for one 36v COB @ 1000ma in a aprox. feet by feet grow..just for fun and experiments :)
 
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Braman

Well-Known Member

you find your chip here:

http://pct.cree.com/dt/index.html

If you know the binning flux of your chip (Y4 [6910] ...--->...DB [13000])
you can calculate lm / W of your lamp.

@1000mA (30% of max. current) your chip will run with a very good efficiency
:peace:
I ordered from alibaba, so the only things I know are - 3500K CXB 3590 80 CRI 36V

Is there a meaningful diference between top bin and lower bin cxb 3590? Like, they are not worth buying them?
 

Black Thumb

Well-Known Member
When a driver has something like this
Output Voltage V1 Nominal 27-54 V for the HLG-240H-54B does that mean it will run the board/cob between 27 and 54 volts ?

will that driver run 9x QB 288 (new 54V design) ?
 
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