Re: [MBZ] Strobing?
> Rolf wrote: > I certainly see it. Leds have to be pulsed or they burn out. No. Heat dissipation is a major limiting factor in the light output of LEDs. The simple way to avoid overheating the LED is to set the current limit to low enough that with constant current the substrate can dissipate the heat fast enough to keep the junction below failure temperature. No pulsing - steady, continuous light output. A trick that works because of how human eyes see is to pulse the drive current. So long as the average is low enough to not damage the junction, the intensity of the light while it's on can be much higher. This is NOT how all LEDs are driven! -- Philip ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing
I was thinking about swapping in LED to the headlamps. Pretty cost ineffective if that application would not work. The glare shield in the euro lamps reduces light bleed head on and a bit to the side. Not silvered so it does not reflect photons back toward the reflectors. clay 1974 450sl - Frosch - Two tone green 1972 220D - Gump - She is green, simple and ran 1995 E300D - Cleo - Used by the Queen of Denial POS 1987 SDL - Beware Nigerian Scammers On Jul 6, 2012, at 9:41 PM, Jim Cathey wrote: > Flicker perception is highly variable. My main objection > is the instant-on/off nature more than any modulation > artifacts. Very jarring. And yes, overly bright on-axis, > overly dim off-axis, and hideously expensive when something > does go wrong. I think LED's might have a place in marker > lights, but not for the big lumen jobs. > > -- Jim > > > > ___ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Blinker maybe has no impact on energy saving, but you will drop amperage draw using LED for always on applications. BiL changed out all lamps to LED in his rig and amperage went from 70 to 7. clay On Jul 6, 2012, at 8:37 PM, David Bruckmann wrote: > I see the same thing. There's a definite strobing effect with LED taillights > and brake lights. Definitely on GM products; not sure about MB. > > To me, the LED blinkers are purely idiotic. The "afterglow" from an > incandescent bulb increases the chances that you will notice a blinker vs. > light that is instantly absent as the flasher cycles. And I don't buy the > argument that there are any significant energy savings to be had in such an > application. > > D. > > On Fri, 6 Jul 2012 17:38:28 -0600, Craig wrote: > >> With subject car about 100 - 150 yards ahead, glance to the left side and >> then slew your eyes to the right side. When I do that, I see the strobing >> very clearly. And, yes, I wear glasses, too, but I cannot see how it >> matters. >> >> >> Craig > > > ___ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
A resistor is all that is needed but that is inefficient and then you lose the ability to control intensity (brake lights). I've found cadillac's brake lights to be the worst. -Rolf On 7/7/2012 10:40 AM, Allan Streib wrote: Max Dillon writes: Almost every single appliance I own uses LED lights, so they are all pulsing and strobing? Guess I'm lucky I don't notice it. Do you notice it everywhere? It used to be pretty obvious on old LED digital displays (calculators, watches) but I always assumed that was because each segment was being driven sequentially by the hardware. Rolf wrote: I certainly see it. Leds have to be pulsed or they burn out. I've never heard that an LED must be pulsed, just need a resisitor in series to control the current. Is this incorrect? ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Manufacturers use PWM (pulse-width modulation) to send a square wave to the LEDs with a peak voltage and current above the continuous rating. This allows the LED to be driven at a much greater brightness that it would have with a continuous (lower) voltage applied to it. Depending on the frequency used to pulse the LEDs, the "on/off" cycles or peak versus continuous voltages, the variation in brightness between the two might be visible. I haven't noticed it myself, but then again, I haven't looked that closely, either. Dan On Jul 7, 2012, at 10:29 AM, Max Dillon wrote: > Almost every single appliance I own uses LED lights, so they are all pulsing > and strobing? Guess I'm lucky I don't notice it. Do you notice it > everywhere? > > > Rolf wrote: > >> I certainly see it. Leds have to be pulsed or they burn out. >> >> Sent via string from my tin can. >> >> > -- > Max Dillon > Charleston SC > '95 E300, '87 300TD > > ___ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Max Dillon writes: > Almost every single appliance I own uses LED lights, so they are all > pulsing and strobing? Guess I'm lucky I don't notice it. Do you > notice it everywhere? It used to be pretty obvious on old LED digital displays (calculators, watches) but I always assumed that was because each segment was being driven sequentially by the hardware. > Rolf wrote: > >>I certainly see it. Leds have to be pulsed or they burn out. I've never heard that an LED must be pulsed, just need a resisitor in series to control the current. Is this incorrect? -- 1983 300D 1979 300SD ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Leds have to be pulsed or they burn out. I disagree. They CAN be brighter WITHOUT burning out IF pulsed. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
I don't find an issue with LEDs but if I am in a flourescent-lighted room for any length of time I start to get eye twitches and headaches. --R On 7/7/12 10:29 AM, Max Dillon wrote: Almost every single appliance I own uses LED lights, so they are all pulsing and strobing? Guess I'm lucky I don't notice it. Do you notice it everywhere? Rolf wrote: I certainly see it. Leds have to be pulsed or they burn out. Sent via string from my tin can. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
On Sat, 07 Jul 2012 09:31:17 -0400 Rolf wrote: > Leds have to be pulsed or they burn out. No, LEDs do not have to be pulsed. Some of the newer high-brightness ones, for example, have a shorter life if they are pulsed. Craig ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Almost every single appliance I own uses LED lights, so they are all pulsing and strobing? Guess I'm lucky I don't notice it. Do you notice it everywhere? Rolf wrote: >I certainly see it. Leds have to be pulsed or they burn out. > >Sent via string from my tin can. > > -- Max Dillon Charleston SC '95 E300, '87 300TD ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
I certainly see it. Leds have to be pulsed or they burn out. Sent via string from my tin can. OK Don wrote: >I'll try that, as I haven' noticed the strobing either. > >On Fri, Jul 6, 2012 at 6:38 PM, Craig wrote: > >> With subject car about 100 - 150 yards ahead, glance to the left side and >> then slew your eyes to the right side. When I do that, I see the strobing >> very clearly. And, yes, I wear glasses, too, but I cannot see how it >> matters. >> >> >> Craig >> >> -- >> >OK Don >2001 ML320 >2012 Passat TDI DSG >1997 Plymouth Grand Voyager >___ >http://www.okiebenz.com >For new and used parts go to www.okiebenz.com >To search list archives http://www.okiebenz.com/archive/ > >To Unsubscribe or change delivery options go to: >http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
The maturation process sucks. That's why I don't do it. Getting _older_, however, seems to be a bit harder to avoid, except the hard way. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
On Jul 6, 2012, at 6:12 PM, relng...@aol.com wrote: > I see lots of cars with LED lights and none of them do what you describe. > Just yesterday I was behind a new Cadillac SUV-thing with bright rear LED > lighting and aside from being overly bright there was no strobing effect. I *think* they (LEDs) are controlled by pulse width modulation. Which means_they_strobe. Imperceptible to most maybe, but my eyes constantly move when driving. The movement of my eyes makes the effect noticeable. And no, I do not wear glasses when driving. Only for reading. The maturation process sucks. Rick Sent from my iPhone ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing
Flicker perception is highly variable. My main objection is the instant-on/off nature more than any modulation artifacts. Very jarring. And yes, overly bright on-axis, overly dim off-axis, and hideously expensive when something does go wrong. I think LED's might have a place in marker lights, but not for the big lumen jobs. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing
> ...Strobing perception is more likely due to neurology - same as those > who > can't look at a <60Hz CRT monitor without getting headaches.You can > see strobe effects some times when watching the wheels of cars going past > you while sitting at a stop light if you swing your eyes one way or the > other. I don't think glasses will have anything to do with perceiving the > strobe effect... > This is a question for an Opthalmologist, not a lay person here. RLE ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing
Peception of halos is due to the image not being in focus on your retina. Yes, cured by a new prescription. Strobing perception is more likely due to neurology - same as those who can't look at a <60Hz CRT monitor without getting headaches.You can see strobe effects some times when watching the wheels of cars going past you while sitting at a stop light if you swing your eyes one way or the other. I don't thinkglasses will have anything to do with perceiving the strobe effect. On Fri, Jul 6, 2012 at 10:39 PM, wrote: > > ...With subject car about 100 - 150 yards ahead, glance to the left side > > and > > then slew your eyes to the right side. When I do that, I see the strobing > > very clearly. And, yes, I wear glasses, too, but I cannot see how it > > matters... > > > I can. It's your correction. > > BTDT with another visual phenomenon (halos around lights at night) which > was eliminated with a small change in my prescription. > > RLE > > ___ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -- OK Don 2001 ML320 2012 Passat TDI DSG 1997 Plymouth Grand Voyager ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing
> ...With subject car about 100 - 150 yards ahead, glance to the left side > and > then slew your eyes to the right side. When I do that, I see the strobing > very clearly. And, yes, I wear glasses, too, but I cannot see how it > matters... > I can. It's your correction. BTDT with another visual phenomenon (halos around lights at night) which was eliminated with a small change in my prescription. RLE ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
I see the same thing. There's a definite strobing effect with LED taillights and brake lights. Definitely on GM products; not sure about MB. To me, the LED blinkers are purely idiotic. The "afterglow" from an incandescent bulb increases the chances that you will notice a blinker vs. light that is instantly absent as the flasher cycles. And I don't buy the argument that there are any significant energy savings to be had in such an application. D. On Fri, 6 Jul 2012 17:38:28 -0600, Craig wrote: >With subject car about 100 - 150 yards ahead, glance to the left side and >then slew your eyes to the right side. When I do that, I see the strobing >very clearly. And, yes, I wear glasses, too, but I cannot see how it >matters. > > >Craig ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] strobing nicht
> I was trying to understand these comments as well. I haven't noticed > any sort of strobing when observing LED taillights. > > And yes, I wear glasses if it matters... > My question was "for those who see strobing, do you wear glasses?" Since you don't see strobing.. RLE ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
Dan Penoff writes: > I was trying to understand these comments as well. I haven't noticed > any sort of strobing when observing LED taillights. I think it's more the instantaneous on/off of LEDs vs. not-quite-as-abrupt brightening/darkening of an incandescent bulb. Also if you are directly in line with the LEDs they are almost blindingly bright. Allan -- 1983 300D 1979 300SD ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
I'll try that, as I haven' noticed the strobing either. On Fri, Jul 6, 2012 at 6:38 PM, Craig wrote: > With subject car about 100 - 150 yards ahead, glance to the left side and > then slew your eyes to the right side. When I do that, I see the strobing > very clearly. And, yes, I wear glasses, too, but I cannot see how it > matters. > > > Craig > > -- > OK Don 2001 ML320 2012 Passat TDI DSG 1997 Plymouth Grand Voyager ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
On Fri, 6 Jul 2012 19:24:27 -0400 Dan Penoff wrote: > I was trying to understand these comments as well. I haven't noticed > any sort of strobing when observing LED taillights. > > And yes, I wear glasses if it matters. With subject car about 100 - 150 yards ahead, glance to the left side and then slew your eyes to the right side. When I do that, I see the strobing very clearly. And, yes, I wear glasses, too, but I cannot see how it matters. Craig ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
I was trying to understand these comments as well. I haven't noticed any sort of strobing when observing LED taillights. And yes, I wear glasses if it matters. Dan On Jul 6, 2012, at 7:12 PM, relng...@aol.com wrote: >> The LEDs themselves are not the problem; the way the engineers >> designed >> the drive circuits for the LEDs is. On some LEDs, you can get more light >> out of them by pulsing the current driving them, with a higher peak >> current but the same average current than just driving them with a >> constant current. If the engineers just drove them with a constant >> current, the illumination would be constant. >> >> I _really_ dislike the strobing in cars, too... >> > How many of you that see this strobing effect wear glasses? > > I see lots of cars with LED lights and none of them do what you describe. > Just yesterday I was behind a new Cadillac SUV-thing with bright rear LED > lighting and aside from being overly bright there was no strobing effect. > > RLE > > ___ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Strobing?
> The LEDs themselves are not the problem; the way the engineers > designed > the drive circuits for the LEDs is. On some LEDs, you can get more light > out of them by pulsing the current driving them, with a higher peak > current but the same average current than just driving them with a > constant current. If the engineers just drove them with a constant > current, the illumination would be constant. > > I _really_ dislike the strobing in cars, too... > How many of you that see this strobing effect wear glasses? I see lots of cars with LED lights and none of them do what you describe. Just yesterday I was behind a new Cadillac SUV-thing with bright rear LED lighting and aside from being overly bright there was no strobing effect. RLE ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
