no, it's just my thermal design in torch: because i didn't designed it for long operation in hot climate, i use some pipe (pipe torch  )

Then it would be better to modify the ballast and reduce the LED current there (usually a single resistor). If it goes into thermal shut down, it mean the junction temperature of the ballast chip exceed 150degC. On that temperature the effects like electro-migration (mainly around bond pads) are severely affecting the component life...

Quote from: marcopete87 on November 12, 2013, 06:48:01 AM

no, it's just my thermal design in torch: because i didn't designed it for long operation in hot climate, i use some pipe (pipe torch  )

Then it would be better to modify the ballast and reduce the LED current there (usually a single resistor). If it goes into thermal shut down, it mean the junction temperature of the ballast chip exceed 150degC. On that temperature the effects like electro-migration (mainly around bond pads) are severely affecting the component life...

i use it a couple of hours on month (it use 12xAA NiMH cells, so it drain them fast), so the problem is aging of capacitors.

ballast is integrated with lamp, so i can't modify it.

These MR16 you can usually unscrew from the lens side , remove the plate with LED's and then you get access to the ballast...

The failing capacitors won't trigger the thermal shut down, it would be really the inadequate ventilation (for the given power; or for the too long usage duty cycle). The failing capacitor will rather cause the fuse to blow up...

Definitely if you use short wiring, you can significantly reduce the load of the input capacitor (the high frequency components remain, but the lower harmonics are the ones causing the majority of the capacitor load and by shorter wires you may redirect them to the batteries)

two days ago i bought another led lamp from ikea, it's 10W 600lm dimmable.
i don't use as dimmable lamp, but as 600lm lamp.
it get quite hot during operation and is built with a lot of smd leds.
it make a very pleasant light, but they could made this more efficient replacing dimmable ballast with fixed light ballast.

i also bought an mr10 lamp 90lm 2.5W.
it's very inefficient, but i need it for low light illumination in this year nativity scene (i'll post photos)

 My biggest complaint with the LED lights/streetlights that they are using to replace some of the HPS fixtures is that the color is too crisp a white.  I prefer the soft white and warm white colors.  As they are much easier on my eyes where as the LED crisp white gives me a headache and makes me have to strain.  Has the LED industry been able to improve on the colors any? 

My biggest complaint with the LED lights/streetlights that they are using to replace some of the HPS fixtures is that the color is too crisp a white.  I prefer the soft white and warm white colors.  As they are much easier on my eyes where as the LED crisp white gives me a headache and makes me have to strain.  Has the LED industry been able to improve on the colors any? 

it depend on which led is used and what kind of optics it needs.
now you can get led with cct from as low as 2700°K to more than 8000°K

My biggest complaint with the LED lights/streetlights that they are using to replace some of the HPS fixtures is that the color is too crisp a white.  I prefer the soft white and warm white colors.  As they are much easier on my eyes where as the LED crisp white gives me a headache and makes me have to strain.  Has the LED industry been able to improve on the colors any? 

There is a trade-off to be made between high efficacy (way above 100lm/W) on one side, vs warm and on the top of that warm color on the other side.

As the road/street lighting is not that much color sensitive application, the high efficacy is the main parameter (quite common is above 100lm/W include ballast and optics losses). And that lead to ~5000..7000K, with CRI50..70 output color.
Actually CRI above 50 (so you can quite well distinguish basic colors) is considered quite good for the safety/security lighting application, what the majority of street/road lighting is about.

I appreciate the info, thank you very much.  I do have sensitive eyes, anything above 4000k and I'm hurting.  They use 3500k in my office which is much better than having the 4100k and 10 times better than the stupid daylight bulbs they use in the office building next to mine.  I would quit my job if I had to deal with that!  I wish I could talk the facilities mgr into switching to 3000K Warm White, I think everyone would be happier and more relaxed.

Well, the color tone choices have their rules.
- Warm light is relaxing, so makes you sleep. Not a good thing in at work.
- Cold light makes you woken and alert, so not a good thing when you are about to go to bed...
- Higher the illumination level, the warm white look unnaturally strange yellowish. So therefore for high levels you have to stay at least at 4000K, but do not go below 3500K. This originate from the fact, than for 1000's years the only source of such high intensity was the sun and it is at about 5000K (direct noon) till 6500K (cloudy day), even to ~8000K of the blue sky. And the day was the time for all main activities, so the awakening effect of such light ("the day is coming, so wake up").
- Lower the illumination level, the colder light look really chilly, for weak light even the 3000K is sometimes too much. Again, this came from the many 1000's years ago, when people relied on the fire pit to make them survive and the fire emitted just low CCT light. First the illuminating fire was used only at evenings before going sleeping (so the relaxing effect), second it provided the necessary heat (high CCT light of low intensity came form the moon or stars at cold night, the fire make such night warm to survive)

good points there.  I prefer a warm relaxed environment to work in which is why I like the 3000k color as well, it's the easiest on my eyes. 

In my office we have 3000K (gradually replaced by 4000K) ceiling lamps (3xF18T8 panels), but I had to arrange my "own" desk lamp using 4000K F21T5, otherwise I would be sleepy all the day and do no work at all...

R.I.P. Philips master led, EOL @ 3000h. 
I've sent an email to philips support, hoping that an 40€ lamp will be replaced for free after 2Y 2m exactely, used base up in open luminaire.

Marco,
  How it died? A loud bang, or what style?

Marco,
  How it died? A loud bang, or what style?

simply it don't turn on anymore.
I've contacted philips help desk, i hope in an replacement 

When you say `Master`, is it the flat bottom one, or the remote phosphor ones?
My LED tests are still in their infancy, I have one of the Philips 9.5 watt GLS classics on my landing, so far running in at 996 hours, then the smaller 5.5 watt classic in my `all night light`, running in at 413 hours, then my 3 Megaman 11 watt over the food prep surfaces in my kitchen, but it will be hard to keep track of the hours these will be used without the painstaking task of logging each of their hours down.