No, it means some marketer needed to fill more space with words that don't actually mean anything.
Koito and Toyota fans, take note!
- Thread starter Alaric Darconville
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No, it means some marketer needed to fill more space with words that don't actually mean anything.
Glass, I knew. Replaceable...are you sure? I didn't know (or didn't recall) the first 8700's lenses being field-replaceable.
There is no advantage to increasing the feed voltage -- LED headlamps don't change their output in response to voltage change the way filament lamps do.
That's quite possible, but it's not a good thing -- light at 25 feet is foreground light, useful only for lanekeeping (or off-road crawling) and because it's so close you don't need much of it.
I agree.
Hilldweller
Enlightened
Yeah; they sold the lenses for around $10. One of the Jeepers I coached on an installation broke his lens wheeling and successfully replaced it.
Those had the heater fans too; kept the ice/snow melted.
The only problem with them was they were a bit wide in the hips and you had to do a bit of trimming to squeeze them in. Part of that ordeal involved moving the airbag sensor, an act that made litigious types giddy with anticipation.
Alaric Darconville
Flashlight Enthusiast
That's a serious concern, really. Direct fit is direct fit-- if a lamp assembly designed to be a "direct replacement" for the OEM part needs to be modified (or the vehicle itself to be modified) that should be a "fail". (Like the CAPA report on the TYC and DEPO lamps that didn't actually FIT the vehicles they were meant to.)
Back on topic: while I would love to see self-contained versions of this family of projectors (BiLED, AFS, ADB, etc) as drop-ins for the Hella 90mm mount, they look slightly too big to fit. Also, Koito doesn't really have an aftermarket channel anything like Hella's. :-(
Hilldweller
Enlightened
No. Not the automotive ones.
They're either on or off. No in-between.
That's not true at all, Hilldweller. Automotive LEDs are dimmable by varying the power input to the emitter(s), and this strategy is widely used in existing LED vehicle lamps. Consider stop/tail lamps and turn/park lamps, or the Koito BiLED unit that is the subject of this thread -- the LEDs are driven at a higher power for high beam mode than for low beam mode. And matrix beam-type ADB depends on dimmability of LEDs; that's fundamentally how it works.
Hilldweller
Enlightened
I stand corrected then.
My LED headlights are on or off. If I don't feed them enough voltage they flicker off...
SubLGT
Flashlight Enthusiast
And in stark contrast to this single LED headlamp, we have Mercedes Benz, who is touting their headlamps with 84 LEDs per lamp.
:nana:http://www.ledinside.com/news/2014/11/mercedes_benz_to_launch_next_generation_multibeam_led_headlamp
Alaric Darconville
Flashlight Enthusiast
The difference is that the Mercedes lamps are ADB, not the standard high/low system.
Not to put too fine of a point on it, but is Toyota one of the firms that generally specifies a good sort of polycarbonate for their lens that isn't going to yellow up and become largely useless in no time flat? This is one of my biggest fears with LED headlamps, as their superior lifespan becomes significantly less useful when you end up having to replace the entire headlight assembly due to discolouration.
Really glad to see LED headlamps taking off more and more in new cars.
Really glad to see LED headlamps taking off more and more in new cars.
Alaric Darconville
Flashlight Enthusiast
Not extremely. Their headlamps can be found to be just as yellowed as any other brands' headlamps. The inferior lifespan of halogen doesn't become less concerning because the headlamp lenses yellow, either.
Oh, of course not. The difference is that, at least as far as I am aware, LED headlamp assemblies tend to be integrated units where the diodes are built into the assembly and replaced at the same time. Halogens, of course, are typically replaced separately.The point I'm getting at is twofold:
a) The additional lifespan of an LED lighting solution will not be fully utilized if the entire unit needs to be pulled and replaced ahead of its time because the polycarbonate lenses fail before the diodes do; and
b) The inclusion of the diodes etc. in the headlight assembly makes them more expensive, at least on the consumer end, which might dissuade drivers from replacing their headlight assemblies when they become yellowed.
It seems to me that headlamp yellowing is a major cause of headlight quality degradation, and better regulation along this point would both save money to consumers (assuming the incremental cost of a 'better' polycarbonate is less than that of the entire assembly replacement avoided) and increase safety.
Just to gain clarification on the LED not being brighter with more voltage, in the context of a better connector as Hildy mentioned potentially improving output...vs the DRL solution saying a drop in voltage could be used to dim the LED, etc.
So, is it possible that the set up that was "improved" had been delivering LESS than optimum current, so the better connector brought it up to spec (Circuitry/driver, etc...now regulating it at full output), whereas before, it had been getting less and was under spec?
Or is it only possible that the old design had a pattern with "too much foreground light"?
So, is it possible that the set up that was "improved" had been delivering LESS than optimum current, so the better connector brought it up to spec (Circuitry/driver, etc...now regulating it at full output), whereas before, it had been getting less and was under spec?
Or is it only possible that the old design had a pattern with "too much foreground light"?
No. It doesn't work this way. The power seen at the headlamp circuit is not seen by the LEDs. The LED driver circuitry, integral to the headlamp assembly, "feeds" the LEDs a particular power even as the input voltage varies.
I see, so there's an inline regulatory function that boosts it if needed, etc.
That would mean the DRL related drop mentioned earlier is done at that point, not before, etc.
Is this related to why the LED flicker without an adapter accessory, as in the 8700 evolution before they made it built-in? That accessory is what did that regulatory function?
There is indeed an LED driver.
Yes.
No, those lamps flickered because the vehicle used PWM (pulse-width modulated) feed to the headlamps. The power is pulsed on and off very rapidly to arrive at (for example) 12.8 V(RMS) at the headlight bulbs. You never see the flicker in a filament lamp, because it doesn't cool down quickly enough to darken between the "on" pulses. But with instant-on/instant-off light sources like LEDs, you see the flicker. The anti-flicker gadget just smooths the power to the lamps, probably with a capacitor and/or inductor type of circuit.
