Flashing taillights

Hi.

I drive one myself, but I find them quite annoying as vehicles in front: The Passat (or all LED taillights).

Earlier, I even took a snapshot that shows that the lights are segmented and are activated one after another.

Where exactly does the segmentation of the power supply take place?

A circuit is integrated into the taillight that performs multiplexing.

SGM

And I thought I was just being overly sensitive, but I also find that flickering/fuzziness extremely annoying.

"When the car in front of me brakes, I react much faster than I do when the regular lights turn on."

I just find it really stupid when you move your eyes and see the individual "beats" as a trail. (almost like in GTA3, but choppy ).

Let's see if I can get this line drawn on the image .

m;

Sure, that would be directly interesting .

Multiplexing actually makes a lot of sense.
This saves a significant amount of electricity.
Furthermore, multiplexing can also be used to control the PWM for the brightness of the taillights/brake lights simultaneously.

I can see the flickering very clearly as well.
My eyes are a little sensitive to that.

SGM

Hi,

I don't understand why something like that would be approved. It's visible, annoying, and certainly not promoting safety.

The desired energy-saving effect could also be achieved with a significantly higher frequency.

Best regards,

Jan.

I've been asking myself this question for years, ever since BMW started using LEDs in the taillights of the 7 Series.

It can't be that the LEDs can't do that, because the ones inside the car are also pulsed. Okay, I also see the ones from the climate control flickering .

Hey, I'm annoyed by this flickering from these boring LEDs! I notice it very well, for example, when someone overtakes me from the left, or when my eyes move somewhere, it's very noticeable! What's the point of saving just 1 watt of electricity when these things consume very little power? They should rather save something on the air conditioning system .

Hi,

The PWM used for the taillights has nothing to do with saving energy!

In various vehicle models, the brake lights and taillights use the same light sources. However, since LEDs cannot be dimmed in the conventional way, their brightness must be controlled using a PWM (Pulse Width Modulation) signal.
However, even in systems where there are two separate light sources for the brake light and taillight, the LEDs must have their brightness limited. The maximum brightness values are determined by the approval requirements.

Unfortunately, a higher clock frequency is often limited by the deteriorating electromagnetic compatibility that results from it.

Hi,
A significant issue is the waste heat generated by LEDs, which reduces their lifespan and light output (luminous flux) or brightness. Using pulsed operation/PWM allows for higher brightness while simultaneously reducing waste heat, thus increasing lifespan. For example, LED blink lights would not achieve the required minimum light intensities when operated with direct current (DC) voltage.Normally, the human eye can no longer perceive individual pulses at frequencies of around 30 Hertz, at least as long as one is looking directly at the light source. With peripheral vision, things are different, as the frequencies are considerably higher.

Best regards from Berlin.
Olli.

Hello.

Eine höhere Regelfrequenz verbietet sich meist leider durch die sich dabei verschlechternde Elektromagnetische Verträglichkeit.
Would a few hundred Hertz already be that bad? A CAN bus, various ECUs (Engine Control Units), mobile phones, microcontrollers, etc., all operate at much higher frequencies. For example, 200 Hz shouldn't be too problematic, should it?

Normally, the human eye can no longer perceive individual pulses at a frequency of about 30 Hertz, at least as long as one is looking directly at the light source. With peripheral illumination, things are different, as the frequencies are considerably higher.
However, this also depends on the type of light source. A relatively heavy tungsten filament will not flicker, whereas non-dimmable LEDs, with their 'steep slope,' still flicker noticeably at 30 Hz.


This low-frequency, pulsed lighting is truly not very easy on the eyes. Especially at night. It will probably get even better when more and more of these flickering devices are driving around on the streets in the future .

Arno wrote:

... Would a few hundred Hertz already be that bad?

Yes, it is.

The problem lies with the harmonics.
What do you think the fun is when your navigation system suddenly tells you to keep driving while you're stopped at a red light, simply because some PWM signal is interfering with your speedometer reading? I've experienced this more than once.

Bertil wrote:

die PWM bei den Rückleuchten hat nix mit Stromsparen zu tun!

That's true, but I didn't write that it was like that.
I referred to that in this context as multiplexing.
Multiplexing can also be used to incorporate PWM (Pulse Width Modulation) for controlling the brightness.

SGM

...
Would a few hundred Hertz already be that bad?


Yes, it is.

The problem lies with the harmonics.
What do you think the fun would be if your navigation system suddenly starts guiding you to drive forward while you're stopped at a red light, simply because some PWM signal is interfering with your speedometer signal? I've experienced this more than once.
You could also filter out the upper harmonics. However, I meant that instead of, for example, 50 Hz, you could clock the LEDs at 100 Hz (or 200 Hz instead of 100 Hz) to minimize the flickering. I don't quite understand why people would accept this flickering.

Hi,

Sure, you can filter, but each filter costs a few extra cents.
And when you consider that millions of people voluntarily spend their time in front of flickering screens, or have done so in the past, or sit under flickering fluorescent lights...

Best regards from Berlin.

Olli.