bout LED resistor

[stevenkoh08]

Hi any expert know where to put the resistor for the LED?

i've done the calculation for my new project 18pcs 3watts high power LED 60 degree of angle at 700ma with supply of 12v

for this i'm going to connect in series/parallel array a strip of 3pcs total six line however the resistor is 1 ohm at 1watt so should i connect it before the LED or after the Led pls help??

I'm getting it from China with the LED data sheet provided there's also a Website Lumen, wavelenght\temp and voltage all can be view

[jc85]

Hi bro, i'll think a commercial high power led driver will be easier and they dun cost alot nowsday. If u are a diy kind of person, u might want to try something like this.

http://www.instructables.com/id/Circuits-f...gh-Power-LED_s/

Btw, I checked quite a few china and taiwan high power led. Although they are at least 25% cheaper, they are half the effectiveness.

Cheers

JC

[stevenkoh08]

Hi bro, i'll think a commercial high power led driver will be easier and they dun cost alot nowsday. If u are a diy kind of person, u might want to try something like this.

http://www.instructables.com/id/Circuits-f...gh-Power-LED_s/

Btw, I checked quite a few china and taiwan high power led. Although they are at least 25% cheaper, they are half the effectiveness.

Cheers

JC

Tks bro for the info already have read up the article yesterday but got two diagram showing before the Led and after the Led

1.http://metku.net/index.html?sect=view&n=1&path=mods/ledcalc/index_eng

2.http://led.linear1.org/led.wiz

try input 12v, 4v, 700ma and 18 LED

for the effectiveness how do we garge able to share more i also got another supplier which i found the LED is from japan from local company

chk out this

ASMT_Jx3x.pdf

[stevenkoh08]

have saw the physical item itself it's very smal almost half the size of normal LED

[stevenkoh08]

for the both LED i've done a calculation and compare to get the 60 degree angle 3watts 700ma with heatsink both with warranty china one 2yrs min price is three times different at factory rate and the japan one need to order at least 500pcs at one go

[stevenkoh08]

so if going for lower cost it'll still be china one

oh onething if i'm going to built one in the near furture anyone here in this forum can come over and help me to test out the lighting like par luman or whatever la

[stevenkoh08]

here is the item list a local supplier send me

[stevenkoh08]

sorry nvr attach in the earier reply

[stevenkoh08]

sorry can't input excel sheet format nvr mind here is the link www.xdlled.com

[stevenkoh08]

oh onething anyone can help to look for this timer

12vDigitalTimer.pdf

[jc85]

sorry can't input excel sheet format nvr mind here is the link www.xdlled.com

Bro, juz compare the lux at 700mA. These china made LED can only provide >90lms with 700mA. Those from SSC, Cree and the one from japan only need 350mA for the same lux.

Cheers

JC

[sherman]

Bro, juz compare the lux at 700mA. These china made LED can only provide >90lms with 700mA. Those from SSC, Cree and the one from japan only need 350mA for the same lux.

Cheers

JC

Meaning those China,Taiwan,Hong Kong,Malaysia ,Italy,etc led has only 50 % of SSC,Cree,etc, efficiency.

Meaning to produce the same amount of light intensity you need to use 2 time the current.

Meaning more heat will be generate .

Hence life is also half

[jackywongto]

Steven, might be worthwhile to invest more on reliable LEDs if you are making one.

Sometimes, you get what you pay for.

just my thoughts.

[stevenkoh08]

oh ok understood liao

tks alot on the info however i going for a try for the china one first order 50pcs blue and 50 pcs white

now on the look out for PLC to have the cycle of sunrise and sunset alike anyone into this

Oh who are able to test for me if i done with the built

[jackywongto]

oh ok understood liao

tks alot on the info however i going for a try for the china one first order 50pcs blue and 50 pcs white

now on the look out for PLC to have the cycle of sunrise and sunset alike anyone into this

Oh who are able to test for me if i done with the built

Cool Bro!

all the best and keep us posted!

[stevenkoh08]

WHO GOT PAR OR LUMEN TESTER meter??

[jc85]

For dimming, what the guys in nano-tank forum are doing is using Arduino to control the dimming effect.

Cheers

JC

[stevenkoh08]

bro can pm me the link

[jc85]

Dun have a specific thread on it, u can search for arduino on the lighting section.

http://www.nano-reef.com/forums/index.php?...lite=%2BArduino

Cheers

JC

[stevenkoh08]

just a stupid qestion how many 3watt 700ma led can a 1000mA buckpucks drive??

[jc85]

It will depend on the voltage instead. Generally, a buckpuck can support up to a series of 6 3W LED.

Do go through the evil66 Ultimate guide if have not.

http://www.nano-reef.com/forums/index.php?showtopic=186982

Cheers

JC

[stevenkoh08]

bro if i'm going to conect it in this way is it the max amp i need is 2.1 amp or 18x0.7amp cause i'm new to such things and need help

diagram.doc

[jc85]

A three string of 6 3W LED on parrallel, ur buckpuck will need to be providing 2.1A and 18vdc.

When in parallel config, the current are divided and voltage is remains the same. The voltage needed is the sum of the total LED voltage in a single string.

Hope this helps.

Cheers

JC

[sherman]

just a stupid qestion how many 3watt 700ma led can a 1000mA buckpucks drive??

Max 6

[sherman]

A three string of 6 3W LED on parrallel, ur buckpuck will need to be providing 2.1A and 18vdc.

When in parallel config, the current are divided and voltage is remains the same. The voltage needed is the sum of the total LED voltage in a single string.

Hope this helps.

Cheers

JC

Shoiuld be 24 vdc and best 2.5 A