hi guys,

probably a quick question, however i have noticed when coming up my drive that the drls flash like some sort of disco.

is this normal? when and why do they flash at times?

cheers

They shouldn't, sounds like they are faulty.

I have noticed that some LED DRL's (Mercedes) when viewed through my rear view mirror seem to 'dance' but not flash on and off? Are you looking at them as a reflection in a window when pulling on to your drive?

The only time your DRL's should dim is when your side/dipped headlights are on.

Probably a faulty LED...

But on the plus side just think about the trafficless driving everybody will be moving out of your way till fixed lol

does it flash like

or

like this

rumour has it, that if all safety/stability controls (like esp, abs etc etc) r switched off, then it "strobes".

others tend to say its the camera playing tricks.

but if ur eyes r playing tricks too, then........

Edited 29 April, 201115 yr by JR RS

thanks guys, yeah good point if people move out the way then great

but dont want to risk being pulled over.

it looks more like the first link you sent.

however in reflection behind car it looks fine.

it was when i was checking my cctv on drive i noticed it. could be the angle but defo looks like it flashes when slowing down and turning up drive.

only noticed it then, never any other time which made me think it was maybe when slowing down and turning??

i was in front of my missus driving back from garage the other day and they never flashed once while i looked in my mirror however i never pulled up drive this time..

cheers

The LED brightness is controlled by pulse width modulation with a rep rate > 40 mS

An electronic camera will catch this and it will appear as strobing.

The human eye has a persistance of vision of about 1/25 of a second so does not.

Those two links above are showing the same thing, its the camera playing tricks both times. I've seen this on TV too, especially Top Gear when they have cars with LED DRL's on their test track.

Odd how they are flashing on the blue vRS but not on the chasing police vRS?

Still, if you saw them flashing when viewed on your CCTV then this explains it, they aren't faulty, it must just be a conflict with how the LED's work and the way in which they are viewed on a camera.

LED's pulse super fast hence if a car has LED rear lights and you move your eyes left to right quickly while the LED rear lights are in front of you then they will flicker, its normal, an CCTV will show it up more it did on my CCTV when i had the 5 series as i had the LED rear lights.

Odd how they are flashing on the blue vRS but not on the chasing police vRS?

i'm still trying to get an answer for that. in the entire clip the blue vrs has its drls strobbing, while the silver vrs does not strobe 1 bit!!

people r telling me camera is causing this effect. but why would it effect just 1 of the cars, when they're both in the same frame/shot?!?!

the mystery continues......

oh ok thanks guys, never thought that it could have been camera.

at least i know now that i am not driving around like a mobile disco.

i'm still trying to get an answer for that. in the entire clip the blue vrs has its drls strobbing, while the silver vrs does not strobe 1 bit!!

people r telling me camera is causing this effect. but why would it effect just 1 of the cars, when they're both in the same frame/shot?!?!

the mystery continues......

Different PWM frequencies driving the lights.

I would guess the electrics in the police cars are heavily modified with all the extra lighting required

The LED brightness is controlled by pulse width modulation with a rep rate > 40 mS

An electronic camera will catch this and it will appear as strobing.

The human eye has a persistance of vision of about 1/25 of a second so does not.

.....Coo....!!!