Contributed by Vasudevan Srisailan

This is a small-scale hydroelectric power generator. It uses a dynamo to which a turbine is fixed. The dynamo uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct electric current. When a jet of water stream is made to fall on the turbine, the turbine rotates, which in turn rotates the coils in the dynamo to produce a pulsing direct current.


The energy conversions are as follows:

• Potential energy (Stationary water possesses potential energy)
• Kinetic energy (Water flowing with a velocity possesses kinetic energy)
• Mechanical energy (the flowing water rotates the turbine)
• Electrical energy (The turbine rotates to produce electric current).

 

Apparatus required:

• A dynamo,
• A circular plastic plate,
• Plastic spoons,
• Glue,
• A wooden box,
• Wires,
• A light emitting diode (LED).

Steps to build the turbine:

1. Make small slits (say 8 slits) at equal distances on the circular plastic plate.
2. Cut the handles of the plastic spoons and make slits at the centre of the plastic spoons.
3. Now insert the plastic spoons into the slits of the circular plastic plate and a little glue is applied. Now the turbine is ready.

Steps to build the generator:

1. Make a hole on one face of the wooden box and insert the dynamo into the hole such that the commutator of the dynamo projects outside the box.
2. Fix the turbine to the dynamo with a suitable nut.
3. Now attach two wires to the dynamo. One of the wires is attached to the spring-loaded copper contact (provided behind the dynamo) which acts as a positive contact and the other wire is attached to the body of the dynamo which acts as a negative contact.
4. Next the positive contact is soldered to the positive terminal of the LED and the negative contact is soldered to the negative terminal of the LED.

 

Now the model is ready for use. When a jet of water is made to fall on the turbine continuously, the turbine starts rotating which in turn rotates the commutator of the dynamo to produce a voltage which makes the LED glow.