09-29-2014, 09:27 AM
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#1146 (permalink)
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Master EcoModder
Join Date: Jun 2009
Location: SC Lowcountry
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Quote:
e*clipse
This is kind of off topic, yet it's on topic. It's not AT ALL addressed at any one or any thing that has happened with this project. It's merely a rant against shotty workmanship and allowing the accounting department to make critical decisions...
For a while now, I've noticed various electronic gadgets fail because of a power supply failure. They will inexplicetly not power up, or cycle on and off rapidly.
For a while now, I've noticed various electronic gadgets fail because of a power supply failure. They will inexplicetly not power up, or cycle on and off rapidly.
I've suspected these devices have failed because they underspec'd a critical capacitor in the power supply. It's very easy to do this with cheap electrolytic capacitors.
Inside this light bulb was a TINY switch mode power supply. The power supply had no way to dissipate heat. It was not connected AT ALL to the heat sink and was wrapped in tape and covered with a case that allowed no air movement. The workmanship was a little shoddy, especially when compared to the heat sink. As I suspected, there was a relatively large 4.7uF electrolytic capacitor. Upon further inspection, I found the Mosfet (the main power switch) with no way to connect its heat sink to anything..... -no I can't believe this - except the bottom of the electrolytic capacitor!!
What a bunch of idiots - the main heat generating device in the power supply is directly connected to the ONE thing that needs protection from excess heat....
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Quote:
MPaulHolmes
That is an engineering crime. Why don't they advertise the LED bulb as 1000 hours, due entirely to a 10 cent 1000 hour life part. It sounds intentional. These dang LEDs last forever. How can we put a limited life on them? Why don't they just add a timing circuit, set to 1000 hours. After the time limit, a relay opens for no good reason, and the part ceases to work. At least then they wouldnt have to mask the intentional failure as incompetence. In modest bulk, 22uf MLCC caps in the controller are like 25 cents each. Their life is rated for 6700 years (24 hours per day at rated temperature I believe, which is friggen 125 degC). You could run it in boiling water until we are all morlochs and eloi. LOL.
IIt's a shame, because I've heard that the led bulbs have a limited life, and always wondered why. It's intentional.
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Planned obsolescence... 
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