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SOLAR CELL FROM A TRANSISTOR


The solar Cells or C? lulas photovoltaic:

In a c? lula photovoltaic, the light excites electrons between layers of semiconducting silicon materials. Does this produce currents? ctricas. The solar cells done with fine silicon capsules, gallium arsenide or another semiconducting material in crystalline state, turn the radiation into electricity of direct form. Now one has cells with conversion efficiencies superiors to 30%. By means of the connection of many of these cells in modules, the cost of the photovoltaic electricity has been reduced much. The present use of the solar cells is limited devices of low power, remote and without maintenance, as buoys and equipment of spaceships.
The solar cells provide only voltage with direct current (dc) or also called DC (cc). That means that the current always flows in a single direction.
We see as we can make one fotocelda with transistors in disuse.

PRECAUTION: The old transistors of germanium contain toxic substances. It is recommended to come with care. To use gloves of rubber and protectors for the eyes.


Do the solar cells contain in their surface silicon as one of the materials to manage “to turn? energ? to lum? Nicaraguan in energ? to? ctrica, the transistors also, some germanium.
For our project we will use power transistors, such as 2N3055 (NPN) or other similars that has discarded.


PROCEDURE:
In order to make these simple solar cells from discarded transistors it is come from the following way::
1. We clear the cover superior of the transistor, with the help of a fretsaw for metal and this way we left discovered its inner connections, as it is observed in the figure.
2. We clean, with well-taken care of if there is some type of material, with the help of a piece of cotton and alcohol.
3. Finally we welded the collector to the emitter, and thus we will have only 2 points of connection: The collector and emitter will be the positive and the base the negative, the voltage that will give will be of approximately 0,6 volts. And the amperage will be really very low.


TEST AND OPERATION: In order to verify the operation of the solar cell, we placed it so that the sunlight affects the elements of the transistor that were shortages when we cleared the cover that covered them, and placed a multimeter in patitas.
It is evident that this cell will not serve to feed a radius transistors, a solar car or some motor, although is very small, since the amperage is minimum.
So that the solar cell that we did can be used we must in series connect it next to other cells of the same type. When connecting the cells in series add the voltages, so that three cells would give approximately 1.5 volts us, but the amperage continues being very low, reason why other cells in parallel can be connected, since in parallel, the voltage stays but the amperage or current is added. In the figure of down you can see an example of a series of cells.

 

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