LED as main light - Page 13

MadTownMax · 04/04/2004, 02:14 PM

Sandist-
I could post some pictures, but the unit just was very dim. I even tried cutting off 10 of the LEDs so that I was running 30 mA through them instead of 20, and I couldn't tell the difference with them on or off next to my PC's.

Maybe these UFO's put out enough intensity .... the LEDs I used produced about 10 candles (10000mcd) at 30mA, I think that you'd want about 100 candles to really be useful for corals. but then again, this array was only using 1.8 watts, so 1W Luxeons would be a big difference.

MadTownMax · 04/04/2004, 02:32 PM

the 1W UFO's put out 20k mcd at 60-degrees, now if someone can find one with an 8-degree angle, that should put out about 150 candles, which would be getting closer to useable, but at $5 a pop, an array would get expensive pretty quickly, - on a nano tank, not too bad.

5-W luxeons put out a lot more light (and are 5X as expensive

)
- are there any 5W UFO's, I could only find 1W.....

and they're big - slightly smaller than a quarter; so closest packing of leds is going to be quite spaced out compared to bare LEDs

fishhawk · 04/04/2004, 04:36 PM

Wattage is a rating of power not necessarily directly comparable to illumination ratings. Light is rated in lumens or lux if I remember correctly....Oooh and my Spurs spanked the Lakers..

Like which is brighter? 2x 75 watt incandescents or 1 x150 watt
Metal Hydride? Both = 150 watts?

Did i do good? did i did i didi i?

eric2524 · 04/04/2004, 05:52 PM

tagging

Obi-dad · 04/04/2004, 06:01 PM

fishhawk, you definitely didn't understand the thought experiment I posted. I was not saying that wattages are exactly equivalent, just pointing out that they are not even in the same ballpark. I will be the first to acknowledge that wattage is not a great indicator.

A better indicator of LEDs not being ready for primetime than wattage is that someone took some lux measurements of an LED array and got 400 to 600. 1 meter deep on a reef the sun gives 45,000 lux (2 orders of magnitude difference). Not even close. But I am hoping the manufacturing technology improves.

olemos · 04/04/2004, 06:25 PM

have you guys looked in to Xenon lamps the same that new cars
use the Kalven ranges form 6000 and up

bzzbee2 · 04/04/2004, 08:24 PM

dont forget you still need a heat sink with a peltier for it to work efficiently.

MadTownMax · 04/05/2004, 07:45 AM

Quote:

Originally posted by bzzbee2
dont forget you still need a heat sink with a peltier for it to work efficiently.

YUP,

BTW, how else would you use a peltier cooler?

robwsup · 04/05/2004, 08:54 AM

With a water jacket.

MadTownMax · 04/05/2004, 05:27 PM

photos are in my gallery

LED:

55W PC:

micaheli · 04/05/2004, 05:31 PM

What exactly are we looking at? The tank on the LEFT is the LED one? or the one on the right? I'm assuming the one on the left is LED's... but.. damn.. thats a DIM tank.. is that 1 led? or just a weird camera.

--Micah

murfman · 04/05/2004, 05:51 PM

from the way i read the pix, the tank on the right is led and the one on the left is the pc, at least that is how the pix are labled

Gomer · 04/05/2004, 06:24 PM

I just hope both photos were shot at the same ISO, aperature and shutter speed. If not, then the photo comparison is null and void

bzzbee2 · 04/05/2004, 06:24 PM

i just mentioned that heat sink thing because i used to work at a computer store. i cannot count the number of times kids would bring in fried computers because they took everything apart, or decided to start the thing up without it completely put together. imo they are a waste. just get a good copper heat sink. an improperly working peltier will just cause problems. JMO

Gomer · 04/05/2004, 06:50 PM

The 5 watt luxeons only last ~ 500 hours for white. Blues might be different though.

Some really nice info on Luxeon stars
http://ledmuseum.home.att.net/agilent.htm

MadTownMax · 04/05/2004, 08:49 PM

20 LED array ( 10000 mcd @30 mA - 4cm X 12cm) is on the left, the tank on the right is a 250W 20K halide. there are close-up pics of the array in my gallery

led array showing wiring:

the pictures both include the halides on the tank on the right for comparison in brightness.

Gomer · 04/05/2004, 08:57 PM

pretty cool. Any word on growth from that LED setup?

MadTownMax · 04/05/2004, 09:02 PM

no macro growth, I didn't bother, it is incredibly dim. The macro that had started growing under a 23W PC bulb died off after two days with this LED array, so I removed it, and am using the 55W 6.7K PC bulb only now.

the very dim picture is a pretty accurate representation of the light this array generated, and the picture of the 55W PC bulb is also a fair representation, I wouldn't have posted the pictures if they were not.

sandisct · 04/05/2004, 10:06 PM

i don't understand y is it so dim.... Maybe you really need to pump up the number of LEDs....

micaheli · 04/05/2004, 10:11 PM

Perhaps you have the voltage WAY down.. Are you sure each bulb is recieving the appropraite voltage/amperage?

MadTownMax · 04/06/2004, 06:32 AM

the 20 LEDs are being powered by a 3V 600mA AC/DC converter, as I posted above. There isn't much to understand, they're not bright.

sfsuphysics · 04/06/2004, 10:06 AM

Well there's your problem right there you're only putting 3 volts through the LEDs! While 3volts is still 90% of 3.3V that does not mean you'll get 90% of the light out, it just doesn't work that way. Chances are if you had a 20mA current nominally if you dumped down to 3V you'll get half that if you're lucky (probably closer to 8mA, so while you have 20 LEDs you're only effectively having the power output of about 8 of them.

MadTownMax · 04/06/2004, 11:09 AM

time to find a new converter

the specs on the LEDs say that they can use voltage from 2.8 - 4V, so I'll get a 4V 900mA converter and then we'll see how dim they are.

BTW, why then are these LEDs labeled as "current driven" and not "voltage driven"?????

Obi-dad · 04/06/2004, 12:20 PM

The best technique is to use a power supply with a higher voltage than required, then use a current limiting resistor. You take the current specified by the manufacturer then calcuate the resistor required.

sandisct · 04/06/2004, 12:42 PM

Did a new array ... this time more compact....

Very Bright!!!!!

04/04/2004, 04:36 PM	#303
fishhawk Registered Member Join Date: Apr 2004 Location: San Antonio, Tx Posts: 204	obidad and wattage of lights Wattage is a rating of power not necessarily directly comparable to illumination ratings. Light is rated in lumens or lux if I remember correctly....Oooh and my Spurs spanked the Lakers.. Like which is brighter? 2x 75 watt incandescents or 1 x150 watt Metal Hydride? Both = 150 watts? Did i do good? did i did i didi i?

04/04/2004, 06:01 PM	#305
Obi-dad Registered Member Join Date: Feb 2003 Location: CT Posts: 4,314	fishhawk, you definitely didn't understand the thought experiment I posted. I was not saying that wattages are exactly equivalent, just pointing out that they are not even in the same ballpark. I will be the first to acknowledge that wattage is not a great indicator. A better indicator of LEDs not being ready for primetime than wattage is that someone took some lux measurements of an LED array and got 400 to 600. 1 meter deep on a reef the sun gives 45,000 lux (2 orders of magnitude difference). Not even close. But I am hoping the manufacturing technology improves. __________________ Greg, member of ARKSC and CTARS Visit our CTARS club website by clicking my RC name then 'visit homepage' - and please support your LFS Current Tank Info: 75g mostly stonies. DIY LEDs (24 CW XP-G, 48 RB XR-E) on dwizum CAT4101 drivers, DIY Hydra controller, SSB, Korallin Ca Reactor, Euroreef skimmer

04/04/2004, 06:25 PM	#306
olemos Premium Member Join Date: Feb 2004 Location: Long Island, NY Posts: 1,791	have you guys looked in to Xenon lamps the same that new cars use the Kalven ranges form 6000 and up __________________ ? Current Tank Info: 350 gl

04/05/2004, 08:54 AM	#309
robwsup Premium Member Join Date: Sep 2001 Location: Orange Park, FL Posts: 2,434	With a water jacket. __________________ Robert Current Tank Info: I own a LFS, so a bunch!

04/05/2004, 05:31 PM	#311
micaheli Registered Member Join Date: Jan 2004 Location: Portland, OR Posts: 189	What exactly are we looking at? The tank on the LEFT is the LED one? or the one on the right? I'm assuming the one on the left is LED's... but.. damn.. thats a DIM tank.. is that 1 led? or just a weird camera. --Micah __________________ NORTHWEST REEF COMMUNITY -- NWREEF.COM Current Tank Info: 75Gal Mixed Reef, Nuvo 8, 29 Biocube frag tank

04/04/2004, 02:14 PM	#301
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	Sandist- I could post some pictures, but the unit just was very dim. I even tried cutting off 10 of the LEDs so that I was running 30 mA through them instead of 20, and I couldn't tell the difference with them on or off next to my PC's. Maybe these UFO's put out enough intensity .... the LEDs I used produced about 10 candles (10000mcd) at 30mA, I think that you'd want about 100 candles to really be useful for corals. but then again, this array was only using 1.8 watts, so 1W Luxeons would be a big difference.

04/04/2004, 02:32 PM	#302
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	the 1W UFO's put out 20k mcd at 60-degrees, now if someone can find one with an 8-degree angle, that should put out about 150 candles, which would be getting closer to useable, but at $5 a pop, an array would get expensive pretty quickly, - on a nano tank, not too bad. 5-W luxeons put out a lot more light (and are 5X as expensive ) - are there any 5W UFO's, I could only find 1W..... and they're big - slightly smaller than a quarter; so closest packing of leds is going to be quite spaced out compared to bare LEDs

04/04/2004, 05:52 PM	#304
eric2524 Registered Member Join Date: Sep 2003 Location: Waterford, Mi Posts: 309	tagging

04/04/2004, 08:24 PM	#307
bzzbee2 Registered Member Join Date: Jan 2004 Location: sacramento Posts: 419	dont forget you still need a heat sink with a peltier for it to work efficiently.

04/05/2004, 05:27 PM	#310
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	photos are in my gallery LED: 55W PC:

04/05/2004, 05:51 PM	#312
murfman Registered Member Join Date: Jan 2004 Location: Colorado Springs Posts: 4,670	from the way i read the pix, the tank on the right is led and the one on the left is the pc, at least that is how the pix are labled

04/05/2004, 06:24 PM	#313
Gomer Registered Member Join Date: Dec 2003 Location: SF Posts: 1,049	I just hope both photos were shot at the same ISO, aperature and shutter speed. If not, then the photo comparison is null and void __________________ -Tony

04/05/2004, 06:24 PM	#314
bzzbee2 Registered Member Join Date: Jan 2004 Location: sacramento Posts: 419	i just mentioned that heat sink thing because i used to work at a computer store. i cannot count the number of times kids would bring in fried computers because they took everything apart, or decided to start the thing up without it completely put together. imo they are a waste. just get a good copper heat sink. an improperly working peltier will just cause problems. JMO

04/05/2004, 06:50 PM	#315
Gomer Registered Member Join Date: Dec 2003 Location: SF Posts: 1,049	The 5 watt luxeons only last ~ 500 hours for white. Blues might be different though. Some really nice info on Luxeon stars http://ledmuseum.home.att.net/agilent.htm __________________ -Tony

04/05/2004, 08:49 PM	#316
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	20 LED array ( 10000 mcd @30 mA - 4cm X 12cm) is on the left, the tank on the right is a 250W 20K halide. there are close-up pics of the array in my gallery led array showing wiring: the pictures both include the halides on the tank on the right for comparison in brightness.

04/05/2004, 08:57 PM	#317
Gomer Registered Member Join Date: Dec 2003 Location: SF Posts: 1,049	pretty cool. Any word on growth from that LED setup? __________________ -Tony

04/05/2004, 09:02 PM	#318
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	no macro growth, I didn't bother, it is incredibly dim. The macro that had started growing under a 23W PC bulb died off after two days with this LED array, so I removed it, and am using the 55W 6.7K PC bulb only now. the very dim picture is a pretty accurate representation of the light this array generated, and the picture of the 55W PC bulb is also a fair representation, I wouldn't have posted the pictures if they were not.

04/05/2004, 10:06 PM	#319
sandisct Moved On Join Date: Mar 2003 Location: Singapore Posts: 133	i don't understand y is it so dim.... Maybe you really need to pump up the number of LEDs....

04/05/2004, 10:11 PM	#320
micaheli Registered Member Join Date: Jan 2004 Location: Portland, OR Posts: 189	Perhaps you have the voltage WAY down.. Are you sure each bulb is recieving the appropraite voltage/amperage? __________________ NORTHWEST REEF COMMUNITY -- NWREEF.COM Current Tank Info: 75Gal Mixed Reef, Nuvo 8, 29 Biocube frag tank

04/06/2004, 06:32 AM	#321
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	the 20 LEDs are being powered by a 3V 600mA AC/DC converter, as I posted above. There isn't much to understand, they're not bright.

04/06/2004, 10:06 AM	#322
sfsuphysics Registered Member Join Date: Jan 2004 Location: San Francisco Posts: 9,103	Well there's your problem right there you're only putting 3 volts through the LEDs! While 3volts is still 90% of 3.3V that does not mean you'll get 90% of the light out, it just doesn't work that way. Chances are if you had a 20mA current nominally if you dumped down to 3V you'll get half that if you're lucky (probably closer to 8mA, so while you have 20 LEDs you're only effectively having the power output of about 8 of them. __________________ Mike

04/06/2004, 11:09 AM	#323
MadTownMax ***erately knowledgable Join Date: Feb 2003 Location: Appleton, WI Posts: 2,750 Blog Entries: 1	time to find a new converter the specs on the LEDs say that they can use voltage from 2.8 - 4V, so I'll get a 4V 900mA converter and then we'll see how dim they are. BTW, why then are these LEDs labeled as "current driven" and not "voltage driven"????? Last edited by MadTownMax; 04/06/2004 at 11:26 AM.

04/06/2004, 12:20 PM	#324
Obi-dad Registered Member Join Date: Feb 2003 Location: CT Posts: 4,314	The best technique is to use a power supply with a higher voltage than required, then use a current limiting resistor. You take the current specified by the manufacturer then calcuate the resistor required. __________________ Greg, member of ARKSC and CTARS Visit our CTARS club website by clicking my RC name then 'visit homepage' - and please support your LFS Current Tank Info: 75g mostly stonies. DIY LEDs (24 CW XP-G, 48 RB XR-E) on dwizum CAT4101 drivers, DIY Hydra controller, SSB, Korallin Ca Reactor, Euroreef skimmer

04/06/2004, 12:42 PM	#325
sandisct Moved On Join Date: Mar 2003 Location: Singapore Posts: 133	New Array Did a new array ... this time more compact.... Very Bright!!!!!