spoken words are in blue
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.
torch has not enough power because the batteries are quite old and
discharged. Then the father brings out a dynamo torch and uses
makes a lot of noise and the light is short lived.
to father: You should use the magic lantern
but during the last few days dark clouds have covered the sun.
remembers that he got a special torch as a present and goes to find
it. The torch works very well - without making any noise.
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
of these experiments is about producing electricity by moving a piece
of magnetic material in a coil (solenoid). A solenoid is a loop
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.
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
a high capacity capacitor, a special one, a great result of the new
technologies used today in the electric and electronic products
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.
take a look to the old dynamo torch and this new one. We need
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.
Can we see the inside of the other torches?
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.