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[15:41:47] <nonasuomy> Is there any benifit to buying higher voltage RGB LED strips 5v/12v/24v would higher voltage keep cooler and be more effecient using less amps?
[15:51:12] <kedgen> Does anyone know if it is possible to run Neopixels on an AVRTiny45?
[15:51:22] <Emil> nonasuomy: nah
[15:51:31] <kedgen> Why can't it be done?
[15:51:40] <Emil> nonasuomy: leds are current driven devices
[15:52:37] <Emil> nonasuomy: no benefit to higher voltage devices
[15:52:51] <Emil> They just have more leds in series
[15:53:24] <Emil> nonasuomy: Well, sure, you will use less amps
[15:53:40] <Emil> But you are using the same energy
[15:55:20] <cehteh> buying better/brighter (at same current) leds and then pwm/dim them helps
[15:55:36] <cehteh> kedgen: should be possible,
[17:23:28] <Casper> nonasuomy: depend on the construction, but higher voltage may be more efficient
[17:23:45] <Casper> as they can put more leds in series and get closer to the target voltage
[17:25:42] <Casper> ex: blue led at 3V, 12/3=4.0 too close, so they put 3 leds in series, for 9V of leds, with an efficiency of 9/12 = 75%... at 24V, 24/3=8.0, so they can use 7 leds in series, for 21V, or 21/24 efficiency = 87.5%
[17:27:20] <cehteh> huh
[17:27:27] <cehteh> strange view :D
[17:28:10] <Emil> Casper: wat
[17:29:00] <Emil> That's definitely not how it works
[17:29:07] <cehteh> less energy wasted in the resistor
[17:29:12] <Casper> that's exactly how it work
[17:29:29] <cehteh> not completely wrong, but not really the point
[17:29:38] <Casper> I just didn't said that the extra voltage goes into the resistor
[17:29:45] <cehteh> where else?
[17:30:15] <Casper> and by efficiency, I mean power used by the led vs total energy used
[17:30:20] <Emil> Leds are not constant voltage devices, even if that's how they are usually modelled
[17:30:26] <cehteh> thats always the same
[17:31:00] <Casper> Emil: so? in led strip, they drive it at the same current no matter what voltage the stripe use
[17:31:15] <Casper> so you can without issue consider them CV devices
[17:31:18] <cehteh> if you have 7 leds in series .. each 3V 20mA ... gives 21V at 20mA
[17:31:45] <cehteh> when you put them in parallel thats 3V each but 7* 20mA ...
[17:31:48] <cehteh> power is the same
[17:32:01] <cehteh> leaving the fact Emil talks about aside
[17:32:18] <cehteh> power is voltage * current
[17:32:26] <Casper> 24V: 7 leds + 1 resistor
[17:32:32] <learath> heh. which do you want to control really well, current or voltage?
[17:32:40] <Casper> 12V 2x (3 leds + resistor)
[17:33:00] <Casper> learath: depend on the application
[17:33:14] <Casper> for led... current
[17:33:38] <cehteh> yes you can possibly drop less at the resistor, on the price that when the resistor gets too small your leds are doomed to bbq themself because of tolerances
[17:33:43] <learath> fair. You really don't care about the voltage as long as it's enough.
[17:34:43] <Emil> Casper: for "standard" voltages (3, 5, 12, 24) yes, you might increase efficiency by opting for series implementation. But "increased voltage -> better efficiency" is false
[17:34:45] <cehteh> the smaller your resistor gets the more suspectible the whole thing is to tolerances (of resistor, leds, power supply)
[17:35:36] <cehteh> increased voltage means less loss on stray resistance .. but that really doesnt matter at that low voltages and currents
[17:36:05] <cehteh> the only thing to get better efficiency with LED's is to use higher efficient leds. ... point donw
[17:36:33] <Emil> cehteh: depends on how you model the situation, higher voltage does mean higher losses on stray resistance
[17:36:56] <cehteh> old leds give 50mcd at 20mA, modern ultrabright leds can give 15000mcd and more at 20mA
[17:37:00] <Casper> Emil: depend on the arrangement, but generally it is true
[17:37:31] <Emil> cehteh: gotta love dem leds <3
[17:37:47] <Snert> smaller wire gauges can be used with higher voltages. But that's a consideration when weight is a factor, such as drones/helis. And the current has to be alot before it matters enough.
[17:37:53] <cehteh> when you operate such a bright led at lets say 10mA its still get much more brightness than the old suckers
[17:38:34] <cehteh> exactly done that for my copters lights :)
[17:38:40] <Snert> amen - modern leds are "burn yo eyes out" bright.
[17:39:09] <Casper> 5V = 1 = 3/5 = 60%, 12V = 3 = 9/12 = 75%, 24V = 7 = 21/24 = 87.5% 30V = 9 = 27/30 = 90%
[17:39:09] <cehteh> just sand the bulb/lens down for a wider angle and softer light
[17:39:16] <Casper> math work
[17:39:37] <cehteh> Casper: and how do leds more efficient there?
[17:39:49] <Casper> ?
[17:40:06] <Casper> I'm talking about power used by led vs total power usage
[17:40:16] <cehteh> that was not the question
[17:40:20] <Casper> led technology is something else
[17:40:53] <cehteh> your idea boils down on how much energy one has to waste on a resistor
[17:41:37] <cehteh> but if you calculate that way, how about operating an led at 3.1V instead 5V with a very small resistor? ....
[17:41:42] <cehteh> there you see the problem :)
[17:43:00] <cehteh> or 3.001V
[17:43:25] <cehteh> :
http://led.linear1.org/1led.wiz?VS=3.001;VF=3;ID=20
[17:43:44] <cehteh> what possibly can go wrong that way :D
[17:46:26] <Emil> Casper: keep in mind that putting leds in series means you cannot address them individually
[17:46:29] <Casper> that's why a smps with current mode driver is the best
[17:47:11] <Casper> Emil: I know that, but so? the initial question was: what is more efficient
[17:47:26] <Emil> Casper: nah, it was for RGB leds, what should I use
[17:47:29] <Lambda_Aurigae> sure you can...1729 marble road, unit 1, unit 2, unit 3
[17:47:54] <Emil> Lambda_Aurigae: ; )
[17:48:44] <Casper> now... to attempt to fix this cable mess....
[17:48:47] <cehteh> Casper: then again, high efficient leds are more efficient, when you can get the same brightness with 5mA rather than 20mA then even a resistor in series would waste less energy
[17:49:05] <Casper> why! why didn'T they went with rj45 instead of hdmi?!? grrrr
[17:49:25] <Casper> cehteh: true, but wasn't in the initial question
[17:49:55] <Casper> just take the old standard led... that was barelly visible at night... now those fricking blue leds are blinding during the day!
[17:50:44] * Lambda_Aurigae hates blue LEDs.
[17:51:29] <Casper> yeah...
[17:51:47] <Casper> my 'server' have a psu with blue leds in the fan
[17:51:59] <Casper> and I have an access point with blue leds...
[17:52:03] <Casper> both are on the ceiling
[17:52:18] <Casper> add the other bright blue leds from the modem and router...
[17:52:30] <Casper> ... and I can READ with that!
[17:54:39] <Lambda_Aurigae> black electrical tape works wonders.
[17:58:32] <Casper> yup
[17:58:48] <Casper> had to sleep for a few days there during the windows change...
[17:59:28] <Casper> logged into the AP and disabled the led, put some tape on the router and modem, but suffered with the psu... it's a pain to get there, so didn't
[18:00:06] <cehteh> the worst i had yet was the blue led on my samsung monitor
[18:00:29] <cehteh> why would anyone put a bright blue led where it shines directly into your eyes ...
[18:00:43] <Lambda_Aurigae> car radios.
[18:00:46] <cehteh> black tape fixed that
[18:01:00] <Lambda_Aurigae> I refused to buy a car once because of the blue LEDs on the radio.
[18:01:10] <cehteh> the server here has some blue leds too .. but they are unobtrusive, thats ok
[18:02:21] <cehteh> its not that i hate them, but often its just unnecessary and unpleasant. a dim green led for 'power' and well visible red or yellow led for failure or hdd access would be more intuitive
[18:04:14] <Casper> Lambda_Aurigae: lol poor seller, must have found that you were a princess! :D
[18:04:29] <Lambda_Aurigae> no, I'm a bastard.
[18:04:45] <Casper> "no, nooo! NOOOOO!!! The car is perfect, but that! That led!" .. :D
[20:24:03] <Emil> Who needs sleep anyways
[20:24:05] <Emil> https://emil.fi/avr
[20:29:13] <DKordic> Emil: Awesome CSS.
[20:29:59] <Emil> DKordic: Isn't it :)
[20:31:13] <Tom_itx> sleep when you're dead
[20:31:57] <Emil> But death comes sooner if one does not sleep enough!
[20:32:29] <Tom_itx> that can't be conclusively proven
[20:32:55] <Emil> It can
[20:33:07] <Emil> Statistics is king
[20:33:31] <Tom_itx> who's to say how long you would live if you did sleep?
[20:34:04] <Emil> Statisticians