Our device is finally finished. We worked hard on it and are proud of what we made. It is water driven generator. It works when water hits the spoons, which cause the magnets on the wheel to spin in front of a coiled wire, creating electricity. This generator is strong enough to make up to three volts. That may not sound like much but, with the basic materials my group had, it is. We learned a lot about electricity and how to make a generator to create our own energy.
How We Did It
Induction – If you have a changing magnetic field, it will create electric current. This is called induction. You can create electric current (induction) with wire, metal and magnets. The formula for electromagnetic force is E = Blv; E (ElectroMagneticForce) = B (strength of field) times L (length of the conductor) times V (velocity of the conductor.
In our generator, we used magnets to create a strong field (‘B’) and copper wire as a conductor (‘L’). Water creates the velocity (‘V’) to move the conductor. The total electromagnetic force we can generate is equal to the force of our magnets times the length of our copper wire times how fast the water is moving.
How our device works – We attached several magnets to a wheel and spun that in front of copper wire that we had coiled tightly and taped in place. We adjusted the position of the magnets (the poles) and we replaced some of the smaller magnets with bigger ones to create a stronger magnetic field. We also coiled the wire as tight as possible to increase our conductor.
Generators use a stator and a rotor to make energy. In our generator, the wire is a stator (the part that doesn’t move) and the magnets are the rotor (the part that rotates). In order to turn the magnets in front of the wire, we attached plastic spoons to the wheel. We tested it in a sink with the water running. When the water hit the spoons, it made the wheel and the magnets (the rotor) turn.
AC vs. DC – Our generator creates alternating current (AC.) Alternating current (AC) is when electrons flow in two directions. DC is when electrons flow only in one direction.
Voltage, Current, Watts – As we learned about electricity, we learned about voltage, current (amps), and watts. Volts measure the electric pressure moving electrons. Current is measured in amps; it is the amount of electricity being used.
Watts = Volts x Amps. Watts measure how much work electricity does in an amount of time.
Energy from our Device – Our device generated 3 volts and almost 1.3 amps. So we created about 3.9 watts. This is much less than a regular household light bulb, but enough for a small nightlight bulb
Three links to learn more: