Cool invention, John, and one that I'm sure you'll get lots of fun use out of (watch your eyes everyone). But what I love most about this Gadget Freak example is that John is 15 and motivated enough to pursue his interest in engineering and science to experiment with new technologies like LED. Keep it up and let's hope there are lots more Johns out there today honing their engineering skills for tomorrow.
Beth, I agree, what a cool Gadget Freak video! John is definitely passionate about LEDs and I can see him becoming the next Thomas Edison of the 21st century. I have a couple students in my Electrical Engineering Technology program (I'm Dept. Chair) at ITT Tech want to share this video with to get them motivated about their field of study. Very Nice work John!!!
Not sure whether you meant that those are better, or this is, but I did notice that they were over $600 and $1000usd respectively. This was about $50, and runs cold. Those, just judging by size, would run VERY hot, and would probably not run for the claimed ~2 hours without overheating. Either way, I wasn't claiming that this is the brightest possible light, just that it is very bright.
John: Nearly as impressive as your design is your knowledge of the different specifications and attention to using that data as part of a process around design tradeoffs. Looking under the covers and considering the pros and cons of different materials and different design choices is all part of the game and you are well on your way to becoming quite a diligent and thoughtful engineer.
You're clearly well on your way to an elustrious career in electrical engineering. Do take a look at the ol' LM317 (LM117,217,317) voltage regulator datasheet. Somewhere in the back is a constant current regulator circuit that you will find very useful in your line of research. Also, check out Natsemi's (now TI) boost switching regulators. Just add an inductor, a FET, a diode and a bunch of caps to nake a voltage step-up constant current regulator. I just finished a controller design to drive those ebay 100W modules (33V @ 3A) off of 12V power. Keep having fun.
John: I am impressed with your results and would like to talk to you about your future. My name is Frank Rudolph and you can reach me on Linked-In under that name. You can reach me on Linked-In or directly at email@example.com, or at firstname.lastname@example.org. At Beacon Power, our corporate charter focuses on alternative energy and sustainability.
Incidentally, if you don't already have a Linked-In account, you should get one now!! Judging from what I have read here, you have a brilliant career ahead of you, and making contacts with a network of people in the industry should start for you right now! Good job! Keep on thinking of new stuff.
You are correct that three 10-watt resistors in parallel will make a 30-watt resistor that is one-third the resistance. But then adding three of these 30-watt resistors in series will only result in a resistor of the original value, but STILL only capable of dissipating 30 Watts, not 90W as you stated.
A slew of announcements about new materials and design concepts for transportation have come out of several trade shows focusing on plastics, aircraft interiors, heavy trucks, and automotive engineering. A few more announcements have come independent of any trade shows, maybe just because it's spring.
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
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