LED bulb current draw
- Thread starter YZINGERR
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superjoe83
Newly Enlightened
What does a 3156 LED like this one draw?
Lets say 18-24 leds per bulb.
A good generalized number would be good.
Thank you!
it depends on what kind of LED's they use, if they use real Lumiled Superflux's they could be run up to 70ma per LED, if using imitation superflux for the most part they run at 20ma per LED
what is your reasoning?
rushnrockt
Newly Enlightened
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- Nov 3, 2008
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Signal lights will either need a load resistor or a separate "blinker" circuit to make them flash at correct speed and possibly throw up an error code. No clue why a break bulb would not work, I haven't seen many, but they all worked properly so far.
LukeA
Flashlight Enthusiast
Beam pattern and illuminance won't be correct.
personally I wouldn't tamper with brake lights and rear turn signals on vehicles because there are legalities involved when you are in an accident and having illegal brake lights and turn signals could reduce your chances of compensation in the case of an accident. I would think in some states you could be ticketed for non standard lighting too.
It has nothing to do with turn signal flash rate, resistors, etc.
Bulb-type lamps (brake, tail, parking, signal, marker, DRL, whatever) rely on a point source of light (glowing filament) that radiates more or less equally in all directions -- a sphere of light -- collecting and distributing that light with optics in the lens and/or reflector. A handful of highly directional emitters arranged in a tower/pyramid/globe/whatever formation cannot even come close to approximating such a sphere of light, so the light distribution from bulb-type lamps equipped with "LED bulbs" like this is seriously compromised and never manages to meet even the minimum legal performance requirements. And that will continue to be the case even when such "LED bulbs" put out an amount of light that begins to approach the luminous flux of the intended bulb —*which they presently do not. Just peering at the operating lamp and saying "Ayup, that looks bright enough to me" doesn't cut it.
Just like with "HID kits" in halogen headlights, the problem with "LED bulbs" is at the concept level, not the implementation level.
Consider: The only LED light source intended for use in imaging-optic systems (along the lines of bulb-type car lights) is the Osram Joule, which is currently used in the high-spec Chevrolet Malibu brake/tail/turn light and in several Ford-made vehicles. Its chief engineer told me they did many millions of dollars' worth of extensive testing and development trying to arrive at a true drop-in for a bulb, that would let OEMs (and maybe eventually end users) retrofit LED light sources in place of bulbs without having to re-engineer or replace any of the optics. The closest they could come was meeting minimal requirements in about 1/3 of the lamps they tested that greatly exceeded the minimum requirements when equipped with the intended filament bulb. Now: d'ya really think some shoestring back-alley hack shop in China selling their stuff on eBay and on websites marketing bling to kids is doing better than the well-funded, fully-equipped and excellently-staffed Osram Opto Semiconductors...?
And that's without even considering the thermal issues with LEDs. You don't really think there's any kind of even minimally adequate heat sinking in those "LED bulbs" you're asking about...do you? Consider that an OE LED brake lamp is doing well to have 90% lumen maintenance after 10 minutes' continuous runtime — this loss in output, and the gain with ambient cold/loss with ambient heat, are compensated for in the basic design — and think about what's going to happen to the already-grossly-inadequate output of a bulb-type brake light equipped with one of these "LED bulbs" once your foot has been on the brake longer than about 60 seconds.
C'mon, think about it: they're safety devices we're talking about here, not toys. Leave 'em alone and let 'em do their job, or if you just gotta have LEDs, buy one of the reputably made replacement light assemblies incorporating LEDs, if they exist for your model. Or build a custom bumper or fascia or light assembly incorporating reputably-made modular LED lamp units. If you want LED DRLs on your vehicle, there are several good add-on options (go look at Hella's, for example). But "LED bulbs" just plain and simply do not work adequately.
(The Joule was released, of course, but only as a light source to be designed into newly-engineered optics. It's working out very well in that kind of service.)
Thats all good and well, but you diverge from my simple question.
LukeA
Flashlight Enthusiast
I'd say between 2W and 5W.
Yup. 'Cause it doesn't matter how much current they draw.
wow, a real help.
hey thanks for your reply :wave:
