Dynamo Electric Torch -
screenplay for a short film

e-mail: earthfriends@rdslink.ro

Scene: A stormy evening at home, with a father and 2 children, lightning flashes outside and the electricity supply is interrupted. The children are scared. The father takes the electric torch from a shelf. The torch has not enough power because the batteries are quite old and discharged. Then the father brings out a dynamo torch and uses it. It makes a lot of noise and the light is short lived.

Child 1 to father: You should use the magic lantern - but during the last few days dark clouds have covered the sun.

Child 2 remembers that he got a special torch as a present and goes to find it. The torch works very well - without making any noise.

Father: I will explain about the way that the torch works when the electric grid is re-established. The lights come back on. The electric bulbs are spreading a strong light. Father goes to the library and takes a thick book of science and opens it at the unit explaining the generation of electricity.

Looking at the pictures Father explains: The first electricity experiments were carried out more than a hundred years ago by scientists. One of these experiments is about producing electricity by moving a piece of magnetic material in a coil (solenoid). A solenoid is a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electrical current is passed through it.
The camera is going on the torch.

Father: The torch uses the same principle to produce electricity. It is a good application of the electromagnetic induction, and it is not at all polluting because it doesn’t use batteries or accumulators The electricity produced by induction is stored in a high capacity capacitor, a special one, a great result of the new technologies used today in the electric and electronic products manufacturing.

Father continues: The new electrical torch is revolutionary because it is not heavy, it is very simple, it isn’t noisy, it doesn’t use any chemical electricity storage devices and it can be used many years without needing to be fixed. An incandescent miniature bulb does not produce the light, but a LED (light emitting diode) does, which is a very energy saving product.

Let’s take a look to the old dynamo torch and this new one. We need to sit around the table, and to use a few tools like: voltmeter, screwdriver and a magnifying lens to see the small components.

Father opens both torches and kids can see that the old dynamo torch contains a small electrical generator, which works with a special mechanical system when it is pushed by the hand.
Camera on action with dynamo torch.
The parts that can be damaged are small wheels, and the light is intermittent. It is also quite difficult to press the switch.

Child 2: Can we see the inside of the other torches?

Father: Tomorrow we will open the old Russian dynamo torch and the Magic Lantern to see how each one operates and identify what are their main parts. Then we can talk about the advantages and disadvantages of using each one of them.