Help in drive 92*Cree XRE P4 leds.

[Murilo]

Hi all
My name is Murilo, im from Brazil and im trying to turn on at same time 92 Cree P4 leds.

Im was thinking about using 5 or 6 Lm3404HV but i dont know if its the best option, can someone give me some tips? ^^
In Lm3404Hv i was thinking in use a 73v x 6Ah supply to drive 3 rails with 18 leds and 2 rails with 19 leds, each one at 1A of current.

Someone have a better way to do this array?

http://img152.imageshack.us/my.php?image=dsc09400qe9.jpg
http://img143.imageshack.us/my.php?image=dsc09391mq7.jpg


Tks all
Hugs
Murilo

PS: (sorry for my english :thumbsdow)

 

[Mash]

Can you give us more info on the use?

 

[Murilo]

Can you give us more info on the use?

Sure,

Im making a little led blade, in this form:
http://img521.imageshack.us/img521/91/dsc09431bw6.jpg

But i dont know which is the best way to drive then, maybe someone have a better idea then my (using lm3404hv)

the heatsink
http://img527.imageshack.us/img527/4931/heatsinkyq8.th.jpg

the blade with glue on heatsink
http://img262.imageshack.us/my.php?image=bladefullcb5.jpg

not necessary this wiring...
http://img527.imageshack.us/my.php?image=halfwiredbladerk7.jpg


can someone help me please? :$

 

[Shaocaholica]

Are they all in series? Won't that be like 300V+ input? Thats pretty high.

 

[dat2zip]

Hi all
My name is Murilo, im from Brazil and im trying to turn on at same time 92 Cree P4 leds.

Im was thinking about using 5 or 6 Lm3404HV but i dont know if its the best option, can someone give me some tips? ^^
In Lm3404Hv i was thinking in use a 73v x 6Ah supply to drive 3 rails with 18 leds and 2 rails with 19 leds, each one at 1A of current.

Someone have a better way to do this array?

http://img152.imageshack.us/my.php?image=dsc09400qe9.jpg
http://img143.imageshack.us/my.php?image=dsc09391mq7.jpg


Tks all
Hugs
Murilo

PS: (sorry for my english :thumbsdow)

What is the supply range? You mention 73V. If that is a battery what is the full charge state and what is the fully discharged state voltage?

You might be better off with a linear regulator for some of the strings and the odd remainder a LM3404HV for the balance.

Another possibility if Vin doesn't vary too much is just a plain resistor.

Wayne

 

[Murilo]

Are they all in series? Won't that be like 300V+ input? Thats pretty high.

Not, on 5*lm3404hv im thinking in 3 lines with 18 leds in series and 2 lines with 19 leds in series, i will use exactly 92 leds, so maybe i need a 74v @6A suplly.


Or can use 6*lm3404hv with 4 lines with 15 leds in series and 2 lines with 16 leds in series, in this configuration i need a ~65v @6/7A supply.


I was thinking in use computer power suplly with mod for higher output, i think i easy get about 20v 8A(i have 5 ps in my hands ), but the problem is the current of it.... i dont know how i can control it..

A friend in China found the lm3404hv for ~8 USD, and just for tell i buy a 300w AT power suplly for less then 8 USD, so idk what i can use





Someone can help me? has some better idea?

Tks
Murilo

 

[Mel_PL]

Hi all

Someone have a better way to do this array?

http://img152.imageshack.us/my.php?image=dsc09400qe9.jpg
http://img143.imageshack.us/my.php?image=dsc09391mq7.jpg

Put off 2 LEDs, you got 90 pieces then.
Make 30 x 3 in series (each "three" with a resistor) fed from appropriate SLA. It will eat about 30 amps .

If you *must* use 92, the extra 2 can also be fed from the same SLA but with another resistor.

Just my idea.

-- M.

 

[Murilo]

Put off 2 LEDs, you got 90 pieces then.
Make 30 x 3 in series (each "three" with a resistor) fed from appropriate SLA. It will eat about 30 amps .

If you *must* use 92, the extra 2 can also be fed from the same SLA but with another resistor.

Just my idea.

-- M.

Tks for ur idea, and yes i need all 92

From the power pc supply i can easy drain 13,8v@15A maybe 11,1v@15A too or try get 14,8 - 15v@10A, if i use to much resistors my final power will be too high i think but my fear is about the current on leds, that on the driver can be regullated to constant 1A thats why im think in lm3404.

 

[Murilo]

Someone plx???

 

[Data]

Murilo

Looks like a fun project.

What does the bank of lights do? If you do not need to strictly regulate the light output then just direct drive the Cree XR-E emitters. They can take 2amps and still hang in there fine (see DB70 link below). If you design the power supply to within +-20% of one amp to each emitter that will be fine. The Cree emitter does not care about amps as much as heat. Just keep it cool. If you run the XR-E at around one amp and keep it cool, it will last for a long time.


my DB70 thread



Cheers
Dave

 

[Murilo]

Murilo

Looks like a fun project.

What does the bank of lights do? If you do not need to strictly regulate the light output then just direct drive the Cree XR-E emitters. They can take 2amps and still hang in there fine (see DB70 link below). If you design the power supply to within +-20% of one amp to each emitter that will be fine. The Cree emitter does not care about amps as much as heat. Just keep it cool. If you run the XR-E at around one amp and keep it cool, it will last for a long time.


my DB70 thread



Cheers
Dave

Tks for showing ur great job in this bank, my 92 leds will be drive to take light trough one lcd display for a diy projector, so, like u say, so if i can keep it cool i can drive it to 1,2A , so i think i will try use 2 of that pc power supply in 15v in parallel with high current diodes in output to give about 15v @25A

Do u have some other idea?

Tks!
Murilo
Brazil