This may not look like a Halloween costume yet…

As a learning exercise, I enhanced a 555/MOSFET PWM controller design with several options, learned KiCad and designed a board with it, and had it fabbed through +OSH Park. Meanwhile, my son decided to be a jellyfish for Halloween. This requires glowing blue tentacles. Of course.

The blue LED strip lights arrive tomorrow, and tonight my son and I stuffed our first PWM board to be able to control LED brightness. Success! An evening father/son project. Even better! :-) 1a56relrlhb36.jpg

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Michael K Johnson October 25, 2014 10:04

With a 9V battery and running at about 1.2 KHz, the 555 consumes about 5 mA. A 5-meter strip of 300 3528 blue LEDs consumes a max of about 42 mA with the 9V battery. Since a typical 9V battery has a capacity of around 500 mAh, with a fresh 9V battery, even at full brightness (though the whole point of this circuit is to run dimmer), even using all 5 meters, the costume should have something like a 10 hour glow life. Trick-or-treating should not be a problem. ☺

Now just waiting for the clear plastic umbrella to arrive to construct the costume…

Karen Storey October 31, 2014 19:05

So…where are the pictures of the finished product?

Michael K Johnson October 31, 2014 19:06

In use in the dark right now. :-)

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