#dominators

Hi! 

So for me and my team’s (without Bubblefish) Psycho Pass cosplay, which I haven’t talk about yet, they wanted the dominators to light up. I laughed. But they visited me and we just went for it. 

And it worked. But I will talk about them more thoroughly another post.

This post is about all the work before the soldering, which was a pain and damn hard to find a good tutorial. So here I am, trying to make one. 

This is what you will need, Lamps, battery of preference(and space), wires, resistors, a switch and a battery holder. Not pictured is tools for soldering.

The switch can be soldered to the wires easily, with one connected to each leg of the switch. Th use of the battery holder is pretty self explanatory.

In this case we choose button batteries because our prop is not so big sp there is not much room for it and we needed to easily be able to switch batteries. 

And these button batteries are 3 volts,(the voltages is written on the package) and the led lights takes 3 volts to light up, so it is a perfect match and no resistors are needed.

So just putting the led on the battery (+leg(longer leg) to the plus side of the battery and -leg(shorter leg) to the -side.) You can even put several leds on the battery, or even series connect them like this. But for some reason,

My understanding is that you need resistors, for everything more than one lamp. when we connected the leds with wire and no resistor they did not light up. Explanation for that: The first led ate all the 3 volts and left none to the other one. So that is why a resistor is needed to split out the voltage over all the lights. I did try connect three 3v leds light to a 9v battery but nothing happened. 

We also tried serie conectng two 3v button batteries, but  that did not light up 2 leds, we did parallel connect the batteries that time, out teori is that if they had been in a serie it would have light up 2 leds but not more. 

But resistors are not scary, we used this website  to help us calculate. 

We put in our voltage supply. 6 since we used two 3v batteries,
The volage drop is 3, the usual for leds, is also says on the package.
The led current depends on colour(I think) and you can find it on the package.
Lastly we put in 12 since that was the amount of leds we wanted to use.

The results was that we needed a 150ohms resistor on each led, with 180 working but not best. 

The resistor should be wrapped around the + leg of the led, soldered and them taped with electrical tape.(For stability and if the + and - legs touch it will short circuit.    

It had to be parallel contected, which means that each led had to have one + wire and and - wire connected to it. 

Here I am halfway. You can say that the switch is the middlepoint, the wire used on this side the battery on this side comes from the - pol on the battery and the other side is the + side. To minimise the amount of wire we made “clusters” where wires from nearby lamps are connected. The holes are for putting the - wire to the leds on the other side and get the + wires to the leds here. 

Had no good picture of it done, because I took a video, for some reason. (edit: can’t get it to work in this post for some reason so here is a link here it does.)

I think that explains is, if you have any questions about this process send me a message I will try to answer or let my buddies who seems to understand this better then me try to answer it. :) 

–Marlin