Group Actions
Engagement
  • Author Author: chris.carter
  • Date Created: Date Created
  • Views 456 views
  • Likes 1 like
  • Comments 2 comments
Related
Recommended

Estimating materials for furry lightup costumes

chris.carter

Here is the next update for the Get Closer Get Closer challenge.  Our mailwoman is starting to drop off materials for our costumes image  DC plugs, LED strips, faux fur.  We love the faux fur.  I am underwhelmed by the brightness of the LEDs.  The picture below makes the strip appear brighter than it is. 

 

image

 

I went with the typical 5m, 12V led strips available everywhere.  The blue one was the first to arrive. 

 

Here is the math.  First, determine the minimum wall adaptor amperage needed.  The package lists power draw for 1 meter as 2.4W (at 12V).  So a 5m strip should draw 2.4*5=12W.  At 12W/12V= 1A.  I need a 12V converter that can supply a minumum of 1A (1000mA)

 

The first wall adaptor I tried said 12V but a test with my multimeter showed 16.7V!!!  That probably would have fried my new LED strip.  The next adaptor in my parts bin said 12V but only supplied 11.4V.  Maybe it is time to stop picking up second-hand converters at Goodwill. 

 

Now LED math.  The disappointment was when powered at 11.4V the brightness was underwhelming.  It is true that blue should appear less bright than other colors and it is only being powered at 11.4V but the brightness of a Flora Neo Pixel is much brighter.  The description of the Neo Pixel gives a draw of 60mA at 5V which is 300mW (60mA*5V).  30 LEDs per meter on the LED strip at 2.4W per meter = 80mW per led (2.4W/30).  That sounds about right, the Neo Pixel is seems at least four times brighter than each individual led on the led strip.  At $16.95/m, the Adafruit NeoPixel strip is not much more than your lowest cost US ebay supplier of a 5m of led strips.  True, it is 1m vs 5m, but the Adafruit strip is nearly five times brighter per meter(if wattage=brightness).  Even though I did not intend to incorporate color shifting into the costumes, it seems like the Neo Pixel might have been a reasonable way to go.  Not just supporting a great company but the math works out for them too.  Sigh.

 

I still have to go back to my parts box and see if I can find a true 12V wall adaptor, but it looks like each outfit (two legs, two arms, torso, and head) is going could require a lot more than 5m of LEDs.  Who would have thought.  Now to decide whether I should order another 5m or 10m in each color.  Also need to do the math and find out how many and what kind of voltage regulators I need. 

 

Non-arduino related: Today I used some sliders to put a tea chest my mother gave us under our butcher block.  These tea chests seem very popular but they take up so much counter space.  Counter space reclaimed, vacant space under the top of the butcher block filled.  Looking at the picture I now realize I could take the cover off the tea chest to save a couple more seconds every morning image

 

 

image

  • What Leslie said (she's so supportive!). Remember that furry things that light up at all are remarkable, noone is going to judge the brigthness but you! That said I do love the NeoPixel strip, and usually power it with 3.7V to knock down the brightness a bit... =D

  • I know you said you were underwhelmed, but they do look pretty cool -- and how many people do have light up furry things?  Think prototype image.  I'm very interested in the issue of power for LED strips, as I do have the neopixel strips ( 5m worth).  So, it will be difficult to keep things small -- especially with the thickness of wire needed.  Anyway, don't be discouraged, because in every project you have the "grass is always greener" problem.  I think your furry items will be rockin' the club or night ski scene.