![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#7
|
|||
|
|||
![]()
Yep, they do flash so as to increase the percieved brightness by driving the
LED to a brighter output in the 50% on cycle while avoiding some of the heat build up with the off cycle. But, I always thought that was at more than 100 Hz where the on-off flashing would not be perceivable - at least by the majority of the population. I can't perceive the 'dotted streaks' you speak of. Just curious, Paul. What was the lowest computer CRT monitor refresh rate you can live with? (The new CFL backlit LCD's don't flash.) Bill Daniels "Paul Hanson" wrote in message ... About the flashing. I am not referring to any mode of load applied to the lights (like putting on your hazzards, or using a turn signal), I am talking about the light cluster units themselves. Not all LED lights for vehicles are created equal. A great deal of them do NOT light up like an incandescent bulb. In fact, most of them I have seen do not. Most have a little circuit board in them, which aside from regulating voltage, dictate how many flashes per second they have while engaged in different modes. Yes, in the US a lot of buses/trucks/etc have LEDs, which IS clearly a superior technology, if properly designed. Unfortunately a great deal (not all mind you) of them DO possess what I call the 'strobe effect', for lack of a better term, I am harping on. This effect happens while they fully on (constant voltage), since they are set to flash say, oh maybe...40-200 times per second, which appears to be on like an incandescent at a steady glance, but not when you run your eyes across it while it is stationary. I have spent a LOT of time on the road, particularly at night and I can assure you that many of the vehicles equipped with LEDs are using a type that has this highly distractive circuit built into them. I fully agree that LED's are the way to go, all I am saying is please, on behalf of all others on the road including me, buy good ones that either flash so quickly that it is undetectable, or do not flash at all like an incandescent. There are many types available, all you have to do before buying one, is turn it on (apply the voltage), then move your eyes across it quickly. Does it make a solid red streak, or did it leave the imprint of a dotted line? Flashing lights are distracting, thats all. A little homework goes a long way, with any purchase. Here are a few links to other discussions about this very same phenomenon that I now realize plagues many more people than myself: (Granted it is a UK forum, but it touches on the same effect, and if you want I'm sure I can find more and from the US) http://www.safespeed.org.uk/forum/vi...8808&highlight =#118808 http://www.safespeed.org.uk/forum/vi...539&postdays=0 &postorder=asc&start=0 Glad you guys just happened to get LEDs that work well, and I agree, the third brake light is indeed a good idea. Paul Hanson At 23:12 10 July 2007, Bumper wrote: Eric, I couldn't figure the 'flashing' comment either, unless he was referring to what sometimes happens with a non-electronic flasher without enough load - - e.g. if you replace your turn signal incandescent lights with LED units, the load won't be enough to operate the OEM flasher. This can be corrected by either installing a suitable electronic flasher or by installing a load resister in parallel with both turn signals. Also good is to install a 3rd brake light at the top of the trailer fin. It may be necessary to make a wedge or bracket so that the LED fixture is perpendicular to the ground (LED's used in these fixtures have a relatively narrow beam angle as compared to incandescent lights). A relay is used for the 'logic' circuit with the coil driven by one turn signal and the NO contact connected to the other. Both turn/brake lights on together, then the 3rd brake light works. Newer Cobra trailers have a bigger tail light fixture installed semi-flush. A shame, since it's still not good quality and the larger hole in the trailer means you can't use standard round truck LED lights easily. I used Maxxima LED fixtures on my trailer, reasonable price and good quality. bumper 'Eric Greenwell' wrote in message news:7BTki.9017$ZO4.6321@trndny05... Paul Hanson wrote: I don't remember (at least recently anyways) seeing a thread about LED lights for trailers. However, I think LED's are a great idea, BUT... I just urge anyone buying them to look into the flash rate (they are constantly blinking as opposed to solidly on like incandescents) of lights you are investigating and choose the highest rate possible. Reason being, it is VERY annoying and distracting to be driving at night, and to have a set of very bright taillights 'strobe' a dotted line across your vision as you scan your eye across them. The lower the flash rate, the more exaggerated the problem is. I am very surprised DOT has not set some kind of minimum standards as to flash rate (as well as better guidelines to headlight lumen maximum/spectrum range, anyone else hate those ultra-bright purple blue headlights?). Remember, if it is distracting to other drivers, you are increasing your chances of an accident as opposed to promoting safety so please do your homework before purchasing. There are plenty of places selling brake/turn/running light units using LEDs that display exactly as the incandescent units do (no flashing/strobing, just on or off). In the USA, LED lights are very common on all sizes of trucks and buses, and none of them flash. "Do the usual, unusually well"--Len Niemi |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Tow cars and trailers | Bill Daniels | Soaring | 88 | May 26th 07 07:49 PM |
Tow cars and trailers | Doug Hoffman | Soaring | 0 | May 23rd 07 12:28 AM |
F/S: Pik-20 and PW-5 trailers | DB | Soaring | 0 | August 9th 05 02:44 PM |
Trailers | Don Johnstone | Soaring | 2 | July 13th 05 09:30 PM |
Pic trailers | culverflyer | Soaring | 1 | May 5th 04 01:37 AM |