magslight
Full Member
   Offline
Gender:  Posts: 121
View Gallery

 |
And the other lanterns, which lamp and which lanterns they are?
Yes ,bright  |
|
|
|
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
Which ones do you mean, the ones in the background?
An the best is: the snow is white again, and has no longer the ugly orange colour of HPS!!! |
|
|
|
|
magslight
Full Member
   Offline
Gender:  Posts: 121
View Gallery

 |
Yes, I think this is the most important thing LOL |
|
|
|
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
I donīt like yellow snow
The ligth in the background is from the train station, it are fluorescent tubes. |
|
|
|
|
Selenium
Newbie
 Offline
Gender:  Posts: 0
View Gallery

 |
An interesting test in winter with snow  |
|
|
|
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
The test will last one year and after that, they decide if more of them will be installed.
So they are also tested during cold winter days and there is a lot light
Never thought, that I could become a fan of LEDs  |
|
|
|
|
Medved
Hero Member
     Offline
Gender:  Posts: 4325
View Gallery
 |
The question is, how long they will last... |
|
|
|
No more selfballasted c***
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
Yes sure, I donīt really believe that they will really last 20 years! |
|
|
|
|
magslight
Full Member
   Offline
Gender:  Posts: 121
View Gallery

 |
I think this will be defect completly when the first LED is diing. This can happen very fast! |
|
|
|
|
Alights
Full Member
   Offline
Posts: 129
View Gallery

USA (120V 60HZ)
 |
I dont understand why we use LEDs for street lighting when there are not even any usable incandescent drop in retrofit LED bulbs that are bright enough. |
|
|
|
|
bluelights
Full Member
   Offline
Gender:  Posts: 130
View Gallery

 |
You can see the road is not lit evenly, this is another problem with LEDs, worse optical control... |
|
|
|
"The orange cloud looks like floating nuclear waste." Save the mercury lamp
|
Medved
Hero Member
     Offline
Gender:  Posts: 4325
View Gallery
 |
@Alights: Making direct incandescent retrofit is very large technical challenge, mainly due to thermal management issues. No wonder, it yield to so much problems with these retrofits (life, use limitation not obvious for normal users, efficacy, light quality, cost,...)
When designing special lantern, the thermal management is much easier, as it might become part of the lantern, so it is not limited to size of any former light source. So at least a chance to get reasonable life is there. But the high required output ask for or huge amount of LED chips or for their high loading. The first drive the cost to levels unacceptable for many users, the second to short life... |
|
|
|
No more selfballasted c***
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
Another aspect is, that LEDs are not that energy efficient than I thought:
One of those fixture needs 52 W. Compared to 50 W HPS it is only about 13 % less,
compared to PL-L 24 W it is even more...  |
|
|
|
|
Medved
Hero Member
     Offline
Gender:  Posts: 4325
View Gallery
 |
PLL does not give as good light distribution control...
And you should compare it with equivalent illumination, so i guess 35W CMH would do the job and with better color quality... |
|
|
|
No more selfballasted c***
|
duluxs
Newbie
 Offline
Gender:  Posts: 0
View Gallery
 |
But PLL is mostly used and common today.
Because of cost and quality reasons, CMH is very rare in germany, especially for "normal" streetlighting. |
|
|
|
|
Selenium
Newbie
 Offline
Gender:  Posts: 0
View Gallery

 |
CMH are more and more used in France for stretlighting and residential area. The quality is very good with a great light distribution control.
The warm white is generally used for street and cool white for pedestrian area.
But i prefer warm white (830) than cool white (942) |
|
|
|
|
bluelights
Full Member
   Offline
Gender:  Posts: 130
View Gallery

 |
Selenium, I thought it would be the other way around - warm for pedestrian areas and cool for street lighting, to keep the drivers acuity (light with more blue spectrum increases awareness). |
|
|
|
"The orange cloud looks like floating nuclear waste." Save the mercury lamp
|
dor123
Hero Member
     Offline
Gender:  Posts: 2588
View Gallery
Other loves are computers, office equipment, A/Cs
 |
The problem in LEDs street lighting in very cold winter is as Medved said is because of the electrolytic capacitor in the "driver" that operate the LEDs. Unlike most electronics (Include the LEDs themselves) that are performs better in cold environment, In electrolytic capacitors it is just the opposite: It is not operating correctly in low temperature. This may cause a chain reaction of unreliable performance of the integrated circuits of the driver thet operates the LEDs and may eventually kill it. |
|
|
|
I"m don't speak English well, and rely on online translating to write in this site. Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the European date format (dd.mm.yyyy).
I lives in Israel, which is a 230-240V, 50hz country.
|
bluelights
Full Member
   Offline
Gender:  Posts: 130
View Gallery

 |
I think it wouldnt matter for the LEDs much if the electrolytic capacitor would be left out (replaced with a small film capacitor) and the LEDs would run with a 100/120Hz ripple. |
|
|
|
"The orange cloud looks like floating nuclear waste." Save the mercury lamp
|
SeanB~1
Full Member
   Offline
Gender:  Posts: 233
View Gallery

 |
The electrolytics could be completely replaced by polycarbonate film capacitors, like those used for motor run and power factor correction, but the replacement is physically a lot larger, cannot be mounted on the board, and costs a whole lot more. This would give a very long lifetime, at the expense of having to use a 25A bridge rectifier to allow self healing in the capacitor without blowing up the power supply side. |
|
|
|
|
Medved
Hero Member
     Offline
Gender:  Posts: 4325
View Gallery
 |
@SeanB~1: Why do you think you would need a 25A rectifier? There is no reason for higher rating then with electrolytics. The only issues with film capacitors are the size and cost. And only in the case you really want smooth light without the 100(or 120)Hz flicker. But such strong requirement is really an overkill for general lighting. Such fast flicker might cause issues only in the presence of mains powered rotating machinery or in the film industry. In first case the lighting equipment will never get so cold, so electrolytes are not a problem, or multi-phase supply might be used, as it is already present on the place; In the second the cost is not as big problem, so specially designed or shorter lived ballasts are of no problem...
My comment about LED's and low temperature (somewhere else) was meant about using the LED system BELOW the RATED temperature range. I didn't meant, then it is impossible (or even too difficult) to design a LED ballast for arctic temperature, only the temperature range requirement has to be included in the specification since the early equipment design. |
|
|
|
No more selfballasted c***
|
SeanB~1
Full Member
   Offline
Gender:  Posts: 233
View Gallery

 |
Film capacitors will give the 10+ year life required in a street lamp, irrespective of temperature swings experienced. The high rating on the rectifier will be needed to handle the high current that the capacitor will draw during self healing, otherwise it will fail as a short circuit and blow a low rated fuse, so you will probably need a 16A fuse and a bridge to match. The high temperature will be experienced irrespective of location, as the heat will be generated by solar heating, and the lows will be there during power failures or group switching failures if the ambient is low enough or there is no cloud cover ( you can make ice in deserts during the night). This precludes most common electrolytic capacitor types, and those that are left are not available in high voltage variants. The bulk capacitor will thus have to be a film unit, as the electronics then become the limit for temperature swings. Using a source with high ripple will lower the efficiency of the output, as you need a high degree of control of lamp current and a proper compensation for die temperature to ensure long life. Best is to have a well regulated primary supply to start with, and use a switching supply to give a lower intermediate rail that can be well smoothed with high temperature range electrolytic before the lamp current is set. |
|
|
|
|
bluelights
Full Member
   Offline
Gender:  Posts: 130
View Gallery

 |
Or maybe use a SMPS which can regulate properly from ~30% of the peak supply voltage, then even without any filter capacitor it will supply the LEDs with constant current most of the time, it will drop out just close to the mains waveform zero crossings. |
|
|
|
"The orange cloud looks like floating nuclear waste." Save the mercury lamp
|