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  1. sr13579

    How to make Grow Light with LED?

    I made a LED setup with blue and red LED that is supposed to help me with indoor planting. I used total 4 LEDs (2 Red and 2 Blue) for one pot of Portolaca flowers. But I think it is not simulating the sunlight properly. How many LEDs am I supposed to use? How should I make the connection?
  2. SEPEHR100

    Invisible laser radiation in DVD drives?

    Recently, I opened up a DVD writer drive for curiosity to see its insides and mechanisms. While the drive casing was open, I plugged SATA power and signal cables to it to see it in action (opening and closing the tray while the laser/lens unit is trying to check if a valid disk is inserted or...
  3. Backgammon Player

    Advertisement to sell bottled water by illuminating a 12-pack of 600ml (20oz) water bottles

    Hello everybody! I own a little beverage store and as an advertisement I hung a 12-pack (4X3 bottles) of emptied PET water bottles with a price tag (above the water pack) from my fence on a rod near the road. It moves a bit in the wind and gained some attention. To make it more attractive I'd...

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