Introduction: LED Atom Model
This is my LED Manganese Atom Model!
Unfortunately, when I built the model, I did not document the steps that I I took to build it, honestly because I did not know what my steps would be, or how it would turn out at the end. But somehow it turned out great! I will try to describe the build process the best I can.
80 LED's of 3 different colors (protons, neutrons, electrons)
plenty of resistors to complete the LED arrays.
1 board of perfboard
metal rod (for the stand)
2x4 wooden base
Step 1: Choose Your Atom
The first step is to choose what atom you want to model. The biggest factor for me in choosing an atom was the quantity of LED's that I wanted to use. Each element has an unique number of protons, neutrons, and electrons. Carbon has 6 protons, 6 electrons, and 6 neutrons. -> this gives a total of 18 LED's in a complete model. Simple, but also probably not too impressive. I wanted an element that had somewhere around 75 LED's to make an impressive model. Manganese has 25 protons, 30 neutrons, and 25 electrons. -> My atom model has a total of 80 LED's. So I chose Manganese.
fyi...[Manganese Uses: Manganese is an important alloying agent. Manganese colors glass an amethyst color and is the coloring agent in natural amethyst. Manganese is an important trace element in nutrition, although exposure to the element is toxic in higher quantities.]
Step 2: Order Your LED's in Bulk!
At this point, it is important to buy your LED's because if your anything like me, you don't want sit around waiting longer than you have to. I used standard 5mm LED's for my nucleus. (Yellow for neutrons, and green for protons.) I also ordered 3mm red LED's to be my electrons, because electrons in real life are much smaller than protons and neutrons. You probably want to order a few extra of each color and size in case you destroy a couple. (I usually find a way to break, burn, or destroy a LED or two.) Good sources for LED's are ebay, mouser, or Digi-key. I used Mouser.
In case your the kind of person that likes to buy locally, you also will be liking to spend way too much on led's if you go to Radio-Shack!
Radio-shack sells a 2 pack of red 5mm LED's for $1.49!
Mouser sells the LED for 16 cents a piece!
Step 3: Plan the Nucleus
Once you know the number of LED's in your model, It is important to calculate how many LED's will be in the Nucleus and how many will be in the electron rings. In my model, I had 55 LED's in my nucleus. To quickly calculate what is the best and easiest way to light up the model, go to the LED series/parallel array wizard website. Fill in the information.
Source Voltage: The voltage of the battery/power supply that you plan on using. I used a 9-volt battery.
Diode Forward Voltage: The specs on the mouser page for the LED I linked to has a diode forward voltage of 1.6V. If you have good specs from your supplier, you'll want to enter the typical forward voltage here. Ideally you'll have something that looks like "3.4V @ 20 mA" If you don't have good specs, this is a list that may help you make decent guesses:
true green 3.3
blue (430 nm) 4.6
Diode Forward Current: If you have good specs from your supplier, you'll want to enter the typical forward current in milliamps here. For 3mm and 5mm LEDs, this is usually 20 mA or close to it. A few special, high-power LEDs exist, but they always come with specs. So if you need to guess, use 20 here. The diode forward current for the LED I linked to from Mouser was 30mA.
Number of LED's in Your Array: The choice is yours. My nucleus used 55 LED's, so I chose 55.
You will probably want to check "View output as [X] wiring diagram; and also [X] help with resistor color codes.
Then click "design my array" and it should output a diagram like the one below, showing what resistors to use, how to have the LED's wired, and how many in a single array.
For this particular example, the wizard thinks that I should use 11 resistors. (18 ohms) with the color code brown-gray-black.
Step 4: Plan the Electron Orbit Rings
Follow the same process as step 3, for calculating what resistors you need for each ring of electrons. Electrons can be tricky however, because each of the orbit rings have a different about of electrons. Manganese has 4 layers. In the closest layer, it has 2 e-. The next has 8 e-. the third has 13 2-, and the last has 2 e-. (e- is short hand for electron.)
So punching those numbers into the array wizard, the 1st layer has 2 e- in a single array with a 220 ohms resistor (red-red-brown).
The next layer has an array of 5 e- with an 18 ohms resistor, (brown-grey-black), and an array of 3 e- with a 150 ohms resistor, (brown-green-brown), for a total of 8 LED's or e- 's.
The third layer has 3 arrays; two with 5 LED's and a 18 ohms resistor, (brown-grey-black), and one array of 3 LED's with at 150 ohms resistor, (brown-green-brown).
The last layer is just like the 1st layer, a single array of 2 LED's with a 220 ohms resistor, (red-red-brown).
Now add the resistors needed from the last two steps to the shopping list, and add a couple spares in case one get's lost.
Step 5: The Nucleus!
Once all the parts have arrived at your door step or mail box, cut up the perf board into little squares, depending how big your nucleus is. I did 5x5 hole pieces, and it wasn't quite big enough once I had all the wires in the cube.
The Idea of the nucleus is to have all the LED's (or protons and neutrons) sticking out of the core of the nucleus, to form a ball of LED goodness. The core is where all the wires and resistors will be stored when completed, insulated and held by hot-glue.
Start with the first panel of the core. and start to wire and solder the diagram from the LED array wizard, with the positive end of each array attached to a common +9V source, and the end of the array soldered onto the resistor soldered onto the common ground.
Repeat this process 6 times until all the panels are of the perf board cube are done and connected together. Once wired together, use hot-glue to insulate the connections to prevent from shorting, and to hold the cube together. You also will want your rod or atom holder to be inserted into the core before the hot glue is solid. Be sure to leave the positive and negative power wires hanging out from the cube! You DO NOT want to forget to keep those wires out!
Step 6: The Motherboard!
Cut another piece of perf board like you did for the nucleus.Then drill a hole in the center of the mother board the size of the rod, and slide onto the nucleus rod and hot glue into place about an inch and a half from the nucleus. This motherboard is where all of the wires from the rings of electrons will be connected to the power-source. Solder the positive wire from the nucleus to one side of another section of perf board, and the negative or ground wire to the other side of the piece of perf board.
Next, strip solid-core wire, and solder the strands of arrays of LED's into one big wire for each layer of the electron orbit layer. Solder the resistor side of the strands to the side of the mother board that the ground wire from the nucleus is connected, and the positive side of the strands to the side of the motherboard that the positive wire from the nucleus is connected. You will want to start in the inner most layer of the electron orbit layers, and form circles with the array strands around the nucleus, forming a model similar to the 1st image.
Use hot glue to insulate "intersection points" of the arrays of the layers to prevent shortages.
Solder all the the common positive connections together, and all the common negative or ground connections together.
Step 7: Check-Point!
At this point, you should have an atom model almost completed, everything but a base to hold the model, along with a key of what colors are the protons, neutrons, and electrons.
Step 8: Create the Master Power Cable!
To make a good-looking power wire, I took two separate wires, both of the same length. Put one end of the wires into a vice, and the other end of the wires in a power drill. Pull the drill away from the vice so the wires are taught, and pull the trigger. The wires will twist together tightly and neatly. Once it gets to the tightness you want, reverse the drill and undo the twist for about a second. This will prevent the wires from coiling up .Take the new cable out of the vice and drill and strip the ends. I use this technique for almost all of the power cables that I need to make myself. Solder one end of the cable to the motherboard, ground to ground and positive to positive.
Step 9: The Base
For my base, I used a simple 2x4 square. First I drilled 3 holes at the front with the diameter of the LED's. (5mm). Then I traced the size of a 9 volt battery on the bottom of the base, and used a drill to roughly create a cavity for the battery to be held in. Then I used the dremel to smooth out that cavity. Next is drilling the hole for the power switch.
Create one last 3 LED array of one of each of the colors. Solder on the appropriate resistor just like before the the negative end of the array. Put the LED's in the 3 holes made to be the key.
The wiring for the base is quite simple. First, solder the positive lead of the battery to one lead of the switch. Solder the other lead of the switch to the positive end of the base LED array. also solder the positive wire from the power cable to the positive end of the base LED so that all of the positive connections of the base are connected. Then solder the negative lead of the battery to the negative end of the LED array, and the negative wire of the power cable to the negative end of the LED array. That's it! Flick the switch and all the LED's should light up!
Step 10: Labels!
I used a clear sheet of a printable label. For each word, I made a few of different sizes and fonts to see what I liked most. One label that said "Manganese" to label the element, the symbol for neutron, proton, and electron for the key. I also added my name to put on the back of the base. Once printed out, it's just as simple as peel and stick for a professional look!
Step 11: Show It Off!
Turn your LED Model into school to get credit, or put on your desk to impress all your friends! Either way, from now on after spending all this time on the model, you will remember the structure of the the atom!
This is my 2nd instructable, (my 1st real instructable,) so be nice! ;) constructive criticism is always welcomed! It is now 2 in the morning as I'm typing up this instructable, if there are confusing instructions or spelling errors, let me know so I can fix them! I'm sure my mind isn't as clear as it could be.