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Maber

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  1. Like
    Maber reacted to W-L in LED using Solar Panel   
    Yes looking at that it will allow you to put multiple LED's in parallel to have more lights however it will drain the batteries faster of course since it will draw a higher amperage. In the PDF there you can see in typical applications where they have two in parallel to provide more brightness. 
     
    -Moved to Hobby Electronics- 
  2. Like
    Maber reacted to dany_boy in LED using Solar Panel   
    Looking at the datasheet you need to adjust the inductor value to accomodate for the extra LEDs. Since this is one of those Chinese ACICs the datasheet is not exactly very professional. Luckily they provide this rather useful chart:

    Considering each LED (typical white 5mm) consumes about 20mA in full brightness, then 6 LEDs would require a 33uH inductor to operate at almost full brightness.
    Cheers
  3. Like
    Maber reacted to mariushm in LED using Solar Panel   
    You can connect leds in series or in parallel  ... when in series, the minimum voltage required to turn on the leds goes up but the current remains the same.  In parallel, the voltage remains the same but current goes up.
     
    It's generally more efficient to wire leds in series, because you lose a lot of energy otherwise in individual resistors to limit the current going through each led.
    There are all kinds of led driver ICs and you can find cheap ready made "boost" led drivers on eBay which take voltage from a battery and raise it as much as needed to light up several leds in series.
    If you want to make your own circuit, you can buy the separate parts required to build such a circuit from online distributors like Farnell or Digikey (Farnell may be better for you in Philippines).
    Here's a link : http://ph.element14.com/led-drivers
    Choose one that can work in "boost" mode if you want it to raise voltage from something low (1.5-4.2v  for example) to higher voltages required to turn on multiple leds in series.
    For pretty much all the chips on that website, you can download the datasheet where they show example circuits and how to determine the other parts required (inductor size for a particular amount of current) and so on.
    You can also find chips that can charge battery from various sources : http://ph.element14.com/battery-charger-ics?searchRef=SearchLookAhead
    or you could even go overboard and use some expensive overkill chips specialized for energy harvesting, for taking as much energy as possible from solar cells to charge battery: http://www.linear.com/parametric/energy_harvesting#!cols_1031,2200,1112,1646,2167,1367,1033,1032!s_0,0!gtd_!2200_Solar
     
  4. Like
    Maber got a reaction from Philosobyte in Trigonometry word problem!   
    I get it now, I just made a mistake in drawing the triangle and draw the angle on the wrong side thats why I use secant.
     
    anyway you really helped me alot. 
  5. Like
    Maber reacted to Philosobyte in Trigonometry word problem!   
    1. Since you know that each vertex has a distance of 336.58 to the center of the circle (each vertex touches the circle) you can split the octagon into triangles. Since the sum of all the interior angles at the center of the octagon has to be 360 degrees, dividing them by 8 gives you 45 degrees for the innermost angle. Each triangle is isosceles, so you can split one of the triangles down the middle to give you two identical right triangles. Then you use the sine function to find the length of half a side; multiply that by two to get the length of the side: 257.6m. 
    2. The picture is self-explanatory, I think, when you plug in the lengths and angles into the sine formula. The answer is 8 miles. What did you do differently? 
    3. 85.43 degrees is the correct answer! congrats. I'm glad that you learned vectors and polar coordinates, but I thought of a much simpler method to solve this when I actually went to solve it *facepalm* Since you can form a right triangle with the sides 1 and 2, you can figure out the angle inside the triangle (63.43 degrees) and add 22 degrees to get the overall bearing.
  6. Like
    Maber reacted to Philosobyte in Trigonometry word problem!   
    1.
    Each point on each side of the octagon must be connected to the center of the octagon by the radius of the circle. This forms a triangle.  The sum of the triangles' angles at the center of the circle must add up to 360 degrees.  You could use the law of cosines, or you could split the side at its midpoint to form two right triangles so you can use more basic trig. 2. 
    Construct a right triangle. If the ship is travelling 16 miles per hour, and 1/4 of an hour has passed, then how far has the ship traveled? That will be one of your sides.  The knowledge of that side, combined with the knowledge that the angle is 30 degrees, is all you need to complete the triangle and figure out all the other sides with trig functions. 3. 
    This problem is basically vectors. Part a should be easy. The plane is moving in the 1st quadrant of the graph. Turning 90 degrees northwest (counterclockwise) would mean you add the 90 degrees to the original angle.  For part b, you have two vectors, one of them (1, 22 degrees) and another of them (2, 112 degrees). Convert the vectors to complex rectangular form, add the vectors together, then convert them back to polar form to find the angle. Here's a resource about polar/rectangular conversion: http://www.teacherschoice.com.au/Maths_Library/Coordinates/polar_-_rectangular_conversion.htm  
    Feel free to ask for clarification.
  7. Like
    Maber reacted to TravisTea in Gtx 570 for $65 worth ?   
    Yeah you're good.
  8. Like
    Maber reacted to Matriox in Gtx 570 for $65 worth ?   
    Honestly that's not a bad deal being that it is around the same horsepower as a 660 which does okay at 1080p games nowadays 
  9. Like
    Maber reacted to nicklmg in Samsung Galaxy S6 edge+ Giveaway   
    We partnered with Collective Digital Studio to give you lucky people the opportunity to be the owner of a new Samsung Galaxy S6 edge+ as part of their "Your Fest Foot Forward" campaign!

    They brought Snapchatter Shaunduras and Viner Ray Ligaya out to a few outdoor music festivals this summer and let them demonstrate how you can step your social media game up a few notches with the camera features on their new Samsung Galaxy S6 edge & edge+ smartphones. Check it out:
     
    https://www.youtube.com/watch?v=lPvM4KP-8_E&index=1&list=PLG_rGpgE_jjgdj1o6lJOjbKMoGZJ5lPSY


    How do I become the lucky new owner of a Samsung Galaxy S6 edge+ smartphone?
     
    Entry is super simple:
     
    1. Watch the video series linked above.
     
    2. Hit that "like" button on the videos in this series over on Samsung's channel.
     
    3. Comment below letting us know what your favorite feature that they highlighted in the series was.
     
     
    One entry (comment) per person. This is a worldwide giveaway. The winner will be selected on EDIT: due to the issues experienced last week, we are extending the deadline to 9/28 at 12pm PT. Best of luck all.
     
    Thanks as always for being awesome
     
    EDIT: The winner is @Maddalol! Congrats, and thanks again to everyone who entered
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