Calling out to Weezard for LED advice
Quote:
Originally Posted by DreadedHermie
[attachment=o213392]
What about this bad boy? (The 12v. version.) Looks like all the goodies are built-in. A little pricey, and maybe marginal headroon for 4 660's. Would you still need CCR's on top of this?
Dude!
You didn't say you had a fat budget.:D
Hell yes! That will work.
That's exactly what I would use if a had 2 pennies to rub together.:)
I'd use the 120Vac input unit and be done with it.
It is truely all you need besides leds, wire, and a heatsink
They are PWM based.
Very little power wasted as heat
Just buy, plug, n play.
I only reneck my own supplies because I have to choose between toys and food. :(
(Sometimes the toys win. Keeps me from gettin fat, ya?):D
So rich!!;)
Must be nice.:smokin:
Aloha nui.
Weezard
Calling out to Weezard for LED advice
Quote:
Originally Posted by DreadedHermie
Yes, I am positively devoted to overthinking (everything) now, not after I've smoked $150+ of LED's!:eek:
Very elegant in its simplicity. Without your guidance I would be making this way harder than it needs to be. Thanks again!
BTW, read somewhere you're on nursing duty this week. Please give my best to your patient, and I hope you're better at nursing than I am at EE. :)
I found a CRAZY thick aluminum cake pan last night, 13' x 9", except it's also non-stick. What's your take on grinding the teflon off so I can epoxy to it?
I'd be very careful.
When Teflon is heated past 4 or 5 hundred degrees F. it produces a poisonous gas.
Not powdered Teflon, an actual gas, so wearing a grinding mask is not gonna save ya.
It WILL kill birds, so it can't be healthy for people.
If you do this, sand the Teflon off by hand, outdoors, down-wind and very slowly.
We seem to be leapfrogging messages:D.
Ciao
Weeze
Calling out to Weezard for LED advice
Quote:
I'd be very careful.
Thanks. I think that real heatsink stock is the way to go.
Quote:
You didn't say you had a fat budget.
Not so much, but the power supply I'd use would be around $75.[attachment=o213400]
By the time I get the 338 heatsinks ($10, plus $10 more for shipping, plus $10 ea. for the 338's, the led driver is actually cheaper. Certainly neater, as well. Think I'm ready to start ordering. Do ya think I should do a build log?
Calling out to Weezard for LED advice
Quote:
Originally Posted by DreadedHermie
Thanks. I think that real heatsink stock is the way to go.
Yeah, that!
Not so much, but the power supply I'd use would be around $75.[attachment=o213400]
By the time I get the 338 heatsinks ($10, plus $10 more for shipping, plus $10 ea. for the 338's, the led driver is actually cheaper. Certainly neater, as well. Think I'm ready to start ordering. Do ya think I should do a build log?
Build log?
Why not?
Grow log?
Abso-freakin-lutely!
Be a good way to give back to the boards that gave so much to us.
On that Driver, the 100-12 might not cut it.
I'd vote for the 60-15 or the 100-15 for the 12-13 volts the red leds are going to want.
My blue wanted 13.8 V. if I remember correctly:stoned: but you won't be able to run it off the same driver.:(
(Reds n blues have different Vf. for a given current.
That would confuse your driver.)
Of course 2 $80 drivers is an option, but you might be able to use one 100-15 driver on the blue with dropping resistors in series with the red leds to shave the difference.
Something to think about.
Aloha,
Weezard.
Calling out to Weezard for LED advice
Quote:
you might be able to use one 100-15 driver on the blue with dropping resistors in series with the red leds to shave the difference.
Nope, I want to run separate drivers for the reds and blues. Using resistors and creating waste heat just seems sloppy to me. If it were a real small lamp it'd be different.
Actually, I've been planning to build two lights, 75-90 watts each. So if I overbuy for the blue driver I can power the blues in both lights with a single driver, yes? I just wanted to build one light at a time so I can work out any kinks before I do the second one.
One thing I noticed, the specs for the PLN-60 and PLN-100 are nearly identical in the 12V versions. The higher voltage PLN-100's begin to outrun the PLN-60's, but the 12V PLN-100 is only rated at 60W. :confused:
The data sheet for the red 630's (I don't think there's one out for the 660's yet) led me to believe they'll want 11.4 volts MAX if I remember right. But you described a trick somewhere for determining what LED's want by using your bench supply. Might have been just turning the thing up until it kicks over to current limiting. Haveta look around for that. Seems wise to experiment with the bench supply before actually purchasing the driver so I get it right. And, I can use the bench supply to drive the LED's, too. :D
But your suggestions are right on the money. Keep 'em coming!:thumbsup:
Calling out to Weezard for LED advice
Quote:
Using resistors and creating waste heat just seems sloppy to me. If it were a real small lamp it'd be different.
Not only did that sound kinda snobby, it's not really what I meant. :stoned: What I was thinking was: only if the difference in voltage requirements of the reds vs. the blues is small, does shaving a volt or two with resistors make sense. :thumbsup: Indeed, in that circumstance, dropping the blues a bit with a resistor may be the wisest solution--especially if bringing in a separate power supply is problematic.
I just got used to planning for a worst-case scenario based on the data sheets for the LEDs. Depending on what bin the dealer decides to send you, it looked like it was very possible to wind up with blue LEDs wanting a full 4 volts more than the reds. :( I guess I resigned myself to thinking that was what I was gonna wind up with.
But Weezard, I guess you've been tellling me your blue and red 15 watters are not that far apart in their voltage requirements. That opens up new possibilities (like judicious use of resistors). Sorry, I'm dense sometimes! :i feel stupid:
Calling out to Weezard for LED advice
Aloha DH
Kinda waitin' 'til you have the LEDs in hand and can use the variable supply to label them with the actual Vf, at the current you want.
You can use the variable voltage function and increase the voltage until you reach the target current. Or you can use CC mode if you turn the voltage all the way up and adjust current up to the target and, in either case, just record your meter readings.
Should come out the same regardless of the approach, ya?
Theory is lots of fun, but, once you have actual facts in hand, design kinda handles it'self.:cool:
Once we know what is, we'll know what needs to be.
No wasted speculation, now mind be mo' free.
Once you've whittled many paths down to 2 or 3.
'tis then, the path that you will choose, seems obvious to me.:D
Sorry!
It happens.:jointsmile:
Weezard
Calling out to Weezard for LED advice
Quote:
Once you've whittled many paths down to 2 or 3.
'tis then, the path that you will choose, seems obvious to me.
Quite right. It's just that I whittle a lot faster than I can type! ;) Sorry if I seem to be going several directions at once (wait a second, I ALWAYS go several directions at once! :thumbsup:) but you've given a LOT of good ideas, some of which required some quick self-education on my end. Seems like if, after considering all the reasonable possibilities, I keep coming back to the same place, that I'm getting real close to the "answer." Thanks to you, I do have a very clear (although "adjustable") picture of where I'm going with this.
I think I've figured out the order I need to acquire parts to make sure they all play nice together. (Although, deep in my heart, I am lusting after that 100-15 driver! :D) Getting as much as possible from few vendors saves a bit on shipping, too.
Already ordered:
1) Arctic Silver epoxy, plus the 2-part cleaning solution set. I'm expecting some kinda grease, anti-oxidant coating, or something like that to be on the heat sinks. ($23.23 shipped)
2) Two 8.5x 13" sections of that heavy heatsink. Grand total with shipping: $62.55. Should be here by Wednesday. Decided to get the sinks together to save shipping, but just building one light right now.
I want to mount two 92mm fans right against the fins of each heatsink, like the 80mm is mounted on the Procyon. I just need to confirm that the mounting holes for the fan line up with gaps between the fins. Once I know what fans I'm using, I can put in the order for the LED's and get finger guards for the fans on the same order. (Later next week.) :dance: Once I get the LED's I can measure 'em and decide on a PS. (Although I REALLY want a 100-15. Did I mention that? :D)
Meanwhile I'll play with the sinks a bit to see how they balance, etc. to decide how to mount the flying hardware (prolly just use ringbolts). MIGHT be nice to be able to hang the light "sideways" too, although I don't plan to use it that way.
Anyway: I believe each heatsink is over 5 lbs. of aluminum. I was planning ("no gotta calculate, overkill will do jus' fine";)) to run (2) 12V 92mm fans gently on a 9V wallwart to keep the junctions as happy as possible. Is this crazy overkill? Is that enough heatsink where a wise man wouldn't even use a fan? You mentioned a thermal switch on your lamp. Are you actually able to get by with passive cooling? Or is the switch doing something other than kicking in your active cooling, like shutting things off above a certain temp?? I'd like to see how you have that set up.
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Kinda waitin' 'til you have the LEDs in hand and can use the variable supply to label them with the actual Vf, at the current you want.
Yes. Your guidance will be critical here. Little apprehensive about firing them up the first time, and I don't even own 'em yet! (See avatar.)
:confused: :what: :confused: :silly: :stupid:
Calling out to Weezard for LED advice
Quote:
Once we know what is, we'll know what needs to be.
No wasted speculation, now mind be mo' free.
Once you've whittled many paths down to 2 or 3.
'tis then, the path that you will choose, seems obvious to me.
Weezard, your knobs clearly go all the way to "11." ;)
You done one-upped the Bard.
You leave me no choice but to reply in Haiku. This is for you, and I call it, "Elegy to some LEDs:"
Tiny sparkling lights
Struggle under current load
Poof! A smoky death.
Regards,
Hermie-san. :stoned:
Calling out to Weezard for LED advice
No worry brah.
Evah li'l t'ing, gone be jus' fine:jointsmile:
Quote:
Originally Posted by DreadedHermie
Weezard, your knobs clearly go all the way to "11." ;)
You done one-upped the Bard.
You leave me no choice but to reply in Haiku. This is for you, and I call it, "Elegy to some LEDs:"
Tiny sparkling lights
Struggle under current load
Poof! A smoky death.
Regards,
Hermie-san. :stoned:
Haiku?
Youku!
I call him.
"Tomorrow."
Shards of pure color
Grew large buds with magic rays
Tonight we smoke bliss.
Weezard-san
:stoned::stoned::stoned: to the tits.:cool:
