RussellMc wrote: > Where are you located? India > Where do you buy from? > What brand LEDs are you using. > How do you know? Seoul Semi. The company rep sent us about 250 HB LEDs of the Z-power=20 series and of different colour temperatures in white and some R,G,Bs. So=20 I can safely assume they are genuine. > > Where were they made? I think South Korea. http://www.acriche.com/en/company/map/map.asp > What certainty do you have about lumen maintenance lifetime and how do yo= u know? Their datasheets. > > Good first test. > ... > ... > > If you KNOW you have genuine Cree, lumileds, Nichia Osram, Seoul semi > (usually) , HP and a few more product then you can skip the above. > Maybe. We have done quite a few light measurements experiments. We would also like to check what the measurements are in different=20 environmental conditions. > > Higher humidity, within limits, can IMPROVE lifetimes in some cases. Is this documented somewhere or did you find this out while testing your=20 lights. Primarily, our aim is to evaluate what kind of warranties we can offer=20 on our products. The LEDs come with tens-of-thousand hours lifetime=20 ratings, but the other components that go in are no where near the=20 figure. An LED could last 10 years, but will a street light built out of=20 them with a power supply, PFC etc. last half that many? That's something=20 we'd like to find. Regards, Mohit. > > More anon ... > > > Russell McMahon > > > > > On 10 September 2010 17:54, Mohit (Lists) wrote: >> Hello everybody, >> >> We are designing a few LED based products that are built around >> high-brightness LEDs and have a PIC, power supply components, heat >> sinks, generic electronics, etc. >> >> The prototypes seem to be performing well in our workplace, i.e. no >> extremes of temperature or humidity, no g-forces, no mishandling... >> >> We are seeking suggestions for DIY reliability and lifetime testing of >> these products, something like "Highly Accelerated Life Test" that we >> could do in our own location using easily available instruments. We'd >> like to do this initially at our end to catch the design flaws >> ourselves, before we send the products off to a test lab that does this >> professionally (but cost more). >> >> Some examples: >> 1. Oven with a pan of water for temperature and humidity testing. >> 2. Oven and a refrigerator for temperature cycling. >> 3. Some kind of shaker for vibration analysis. >> >> Also, can anybody relate experiences they may have had with these test l= abs? >> >> Regards, >> Mohit. >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .