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Bioshock Big Daddy costume Answered

For Halloween, I've been asked to go as a Big Daddy from Bioshock to a party. Going over the top as I normally do for such things, I'd planed on not only making the drill rotate on the arm, but also the eyes light up. While I've wired motors before, I've never done the same with LED's, which lead to some interesting electrical problems. In total, I'd planned on having all 8 eyes wired up with two different sets of LED's, 4 red and 4 yellow per eye. The idea was to have a pack on my waist set up with the power supply and controls. The power supply was going to be 6 9-volt batteries all wired in series (providing 54 volts of power) connected to a push switch. The push switch would be the on/off switch, with the lead going to a toggle switch. The lead would connect to the middle input, the top would lead to the red LED's, and the bottom would lead to the yellow LED's. The LED's were going to be wired in series as well inside their housing, which was going to be cross sections of multiple Sobe bottles with holes drilled through it for the wires to go through. The eyes were all going to be run in series, with resisters at the end of the series before connecting to the power supply again.

1) does the plastic bottle pose any risk of short circuiting the LED's? Electrical tape can always be applied but the question of if it would be a good idea came up.

2) With 54 volts being generated from those 6 nine-volt batteries, what precautions would be recommended to make sure I don't get 50 mA through the heart if something does go wrong?

3) If possible, can anyone suggest a more efficient way of wiring or working the circuit?

4 Replies

mpilchfamilyBest Answer (author)2012-10-01

Not going to work that way and your using way too much power for the LEDs. All you need is a single 9V battery for each set of 8 LEDs. Each set of 8 should be wired with 4 LEDS in series with a 6.9 Ohm resistor at the end. Take those 2 sets of 4 LEDs and wire them together in Parallel. Just like the picture below.

Of course you can play around with how you want it wired but only use one 9V battery per color set of LEDs. If you use the full 54V of the battery pack you'll be burning up your resistors and LEDs. You could wire all 16 together to a single battery like in the other image.

Plastic is an insulator so you don't have to worry about shorting anything. But still solder everything together and cover any exposed connections with heat shrink or electrical tape.

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Nanomd (author)mpilchfamily2012-10-01

Thank you kindly for your quick response! with this set up, will all of the LED's be on all the time? or will I still be able to use the push switch / toggle switch set up I had previously mentioned for the on/off and color selector?

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frollard (author)mpilchfamily2012-10-01


"do the math"

If you absolutely must have 9v use 6AA batteries in series. 9v is way out of its league if you want to power something like this for more than an hour.

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mpilchfamily (author)2012-10-01

Just place a switch between the power source and the LEDs. Making 2 sets like the first diagram will be your best bet. They can both share the same 9V source. Then you can use an on/off/on switch to switch between your colors.

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