An HHO or Brown gas generator is an interesting and often misunderstood technology.
The Brown gas generator uses electrolysis to split water (H2O) into it´s base molecules, 2 hydrogen and 1 oxygen molecule.
This is why it is often referred to as an HHO gas generator.

Step 1: Stuff You'll Need

An empty cup
Dc 5v power supply (You can also use batteries)
Glue gun
Two plated nails 
Two rubber washers 
Cardboard strip
Stripped copper wires
Led light

Step 2: Getting Started

Fill the cup till there's about a centimeter of space left.

Step 3: Starting the Electrolysis Process

Add about one teaspoon of salt to the water.

Mix desently!

Step 4: Starting the Base

Attach your strip of cardboard across the middle using hot-glue. 

Step 5: Adding the Nails

Attach e the DC power to the nails. Now hot glue the nails to the cardboard

Step 6: Adding the Led Light

Push the led light though the rubber washer. 

Now add a copper wire to the negitive lead.

Step 7: Adding the Led to the Build

Hot-Glue the washer to the cardboard.

Put the negitive lead into water. Now attach the postive lead to the nail.

Then add the second washer on top.

Step 8: You Did It!

Now plug in your power source, You'll see a reaction starting on one of the nails, This is HHO. The other nail is oxygen.
kiteman's right, oxygen cannot exist for any extended period of time as a single molecule because it's so volatile. in fact the actual chemical formula for water isn't h20 it's h4o2 hydrogen four oxygen 2 because what your doing is making two water molecules for every single reaction. <br> <br>i've done this before, though your setup is nice and simple; the brown-ness of your gas and later water is due to your electrodes being made of iron or steel. the fun thing is if you use copper electrodes then the water turns blue as the copper breaks down and becomes suspended. i don't think it's related to copper sulfate, though it has the same blue color as copper sulfate. <br> <br>as for the whole HHO theory, it's bunk through and through, in order to get HHHHO2 you need to dump into the reaction a certain amount of energy that is always going to be more than what HHO will generate. this is like one of the laws of thermodynamics, any process cannot create energy, tearing water apart and putting it back together isn't going to net you any free energy, you'll lose energy to heat, friction, and hysteris in the electric part of your system. though in the future if we ever get good at hydrogen storage it might become feasible to use this method as a way to move our energy to where we want it, namely our cars and motorcycles and things that go vroom! <br> <br>i found that the best way to capture the gas is with something like a two liter bottle that's turned upside down, you cut holes in it's neck putting one electrode inside the bottle with wire that still has it's rubber coating, only striping it at the point that is inside the bottle. then using radioshack wire just wrap wire around the opening leaving some space for water to flow. i did this once with a sobe bottle while living in an apartment, bad place to do it but i got a nice bang when the hydrogen lit.
I've tried this in a conseled container with some copper rods. Is the copper has made the water blue. Is the copper a better metal to use then the steel?
<p>no stainless steel or graphite works best add more steel than in this experiment sand the steel too </p>
<em>An HHO or Brown gas generator is an interesting and often misunderstood technology. <br>The Brown gas generator uses electrolysis to split water (H2O) into it&Acirc;&acute;s base molecules, 2 hydrogen and 1 oxygen molecule. <br>This is why it is often referred to as an HHO gas generator.</em> <br> <br>A few factual points. <br> <br>So-called &quot;Brown's gas&quot; or &quot;HHO&quot; generators are fake. According to their advocates, they somehow use electricity in a special way to produce single-atom molecules of hydrogen and oxygen. This is the source of the name &quot;HHO&quot;. They claim these molecules can burn to produce more energy than &quot;normal&quot; H<sub>2</sub> and O<sub>2</sub>. They also claim the flame will burn hit enough to burn through steel, yet not burn human skin. <br> <br>What you have made is a perfectly normal electrolysis unit (although the safety aspects is a little suspect), producing normal H<sub>2</sub> and O<sub>2</sub> at the electrodes. <br> <br>Safety notes: <br> <br>You are connecting water to the main supply. Be careful not to hurt yourself. <br> <br>Fun note: <br> <br>Try adding a lid to the unit, with a tube in the lid. <br> <br>Use the tube to send the mixture of gasses into another pot, thus time with very soapy water in it. <br> <br>After a few minutes, or when you have a pile of bubbles, use a match on a long stick to light the bubbles. <br> <br>;-) <br> <br>
I'm going to try the water with soap, But outside! And thanks for the comment! :D
Take video, and add it as a final step!