ITTSB.EU Blog Forum
ITTSB Blog Specific => ITTSB General Discussion => Topic started by: Kiriakos GR on March 07, 2018, 04:56:17 PM
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Several weeks ago I shopped 30 pcs of identical type LED about using them so I to repair two battery chargers.
Supposed electrical specifications:
2.3V for RED (20mA)
3.2V for Green (20mA)
My repair’s when successful and I thought to buy some extra stock of such LED for future use, and I did that by shopping from another seller.
Now I did receive 50 LED which none of them this is 100% similar to its other.
First indication which alerted me this is level of luminosity at RED color, it seems that I won a jackpot, entire batch of such LED they have issues and differentiate at RED color.
Second jackpot this is broken compatibility with previously shopped LED of this type.
Third Jackpot this is that such LED they can work as replacement of damaged LED’s because of their different and lower forward voltage at RED color.
Fourth and last Jackpot this is manufacturing quality at one electrical parameter this named as: Tolerance of forward voltage (example) ±0.05V
Branded LED manufacturers they do deliver such a specification, and this works as warranty that entire batch of their products they will deliver similar luminosity at specified operational forward voltage.
These 50 pieces of garbage which I got, after careful testing these now could be classified in four categories.
1) Dead ones DOA (five pieces)
2) Vast majority (2V 16~24mA)
3) Low performance ( 2V 4~6mA nine pieces)
4) High – over-driving (2V 26~30mA ten pieces)
Ebay seller was notified and he were honest and refunded.