This Instructable shows, how to build an easy DIY hydrogen generator.

Materials needed for this project:
- Empty container with lid
- Cables
- Pencil
- Luster terminals
- Hot glue gun
- DC Power Supply
- Drill
- Funnel
- Balloon

Step 1: Build the Anode

For the anode, you need an old pencil, a knife, a luster terminal, cables and a hot glue gun.

Take the pencil and strip it with a knife, until you have the lead. Put the lead into the luster terminal and tighten the screw. (Don't screw the terminal too tight, as that will break the lead)

Strip the ends of a cable and put the ends into the other side of the luster terminal.

Seal the terminal and cable with hot glue. Make sure everything is watertight. The only part which mustn't be covered in hot glue, is the lead.

As you can see I used two pieces of lead and put them into two terminals. I connected the two terminals to the same cable. This increases the lead surface, and gives us a higher production quantity.

Step 2: Build the Cathode

For the cathode, you need a cable and a cable stripper.

Strip 10-20cm of the cable and roll it around a pencil. This piece of copper, is the finished cathode.

You can also attach a piece of copper metal to the cathode to increase the surface.

Step 3: Build the Cap of the Container

For this step, you will need the lid of your container, the funnel, a drill, your anode, your cathode and the hot glue gun.

Drill a hole into the lid of your container, the hole should be big enough, for the end of the funnel.
After you drilled the hole, insert the end of the funnel and attach it with hot glue. (Be careful, that the hot glue isn't too hot! If it is too hot it will melt through the funnel and your container.)

After the glue is cold, glue the cathode on the inside of the funnel and the anode on the outside.

Know that you attached the electrodes, drill a small hole into the lid and put the cables through. Seal everything with hot glue.

Step 4: Hack the Power Supply

Before hacking the power supply, please make sure it isn't plugged in!

Hacking a power supply is easy. You only have to connect the green cable with a black cable (ground). Make sure not to solder the two, because in case of a short circuit you have to disconnect the two cables and reconnect them in order to reset the fuse in the power supply (It's a good idea to put in a switch).

The power supply will start running, as soon as the green cable is connected to the ground. Now you have a DC power supply!

To use the power supply, strip a blue cable (-12V) and a yellow cable (+12V). Put the stripped cables into a luster terminal.

Step 5: The Final Setup

Now that everything is finished, you only need to fill the container with tap water (you should also add a bit of salt) and place the lid on top.

Attach the cables to the power supply and turn the power supply on. (You should see small bubbles rising from the electrodes now)

The last step is to put a balloon on top of the funnel, to catch the hydrogen gas.

Step 6: WARNINGS

NEVER attach the hydrogen generator to a normal power outlet.
!ONLY use low voltage currents!

Hydrogen is highly FLAMMABLE make sure you don't burn the gas uncontrolled or in closed buildings. Also make sure, to keep a safe distance when burning the gas.

Step 7: Educational Part

If you are not only interested in building a hydrogen generator, but also in the chemical background, please read this part of the instructable.

Electrolysis:
Electrolysis is an endothermic reaction. This means, the reaction is only running if you add energy to the system. This is achieved with our DC-Power supply. The power supply pulls the electrons out of the anode and pushes them to the cathode.

The electrons are from the water molecules. The power supply forces the water molecules (HHO) to split into a positive loaded hydrogen Ion (H+) and a negative loaded hydroxide ion (OH-).

Due to electromagnetic forces the positiv loaded hydrogen ions are pulled towards the cathode, and the hydroxide ions are pulled towards the anode.

As the cathode offers electrons to the hydrogen ions, the hydrogen ions become hydrogen gas (HH).

Because the anode pulls electrons, it takes the electrons of the hydroxide ions and the hydroxide ions become hydrogen ions, as well as oxygen gas (OO). The hydrogen ions travel to the cathode afterwards.

Why do we use pencil lead as the anode?:
We use pencil lead as anodes, because metals (except for platinum) are oxidised due to electrochemical reactions in the container. That means if you use an iron anode it would basically rust away while you produce hydrogen. The same thing happens when you use copper. The copper turns into copper oxide. This slows down your hydrogen production and gives the water a bad colour.