The photovoltaic cell is an electrical device that converts light energy ( sunlight or artificial ) directly into electricity by the photovoltaic effect . It is a form of photovoltaic cell that , when exposed to light , can generate and support an electric current , without being connected to any external power source , but require an external load to the power consumption .
Photovoltaic solar panels are made of silicon , the same raw material of transistors and diodes that use common electronics. In practice if we can expose the silicon in the sun we get the same result of the silicon solar cell. A good utility for power transistors ( TO3 types ) or metallic encapsulation is recycling , using them in a solar panel .
Photovoltaic solar panels are made of silicon , the same raw material of transistors and diodes that use common electronics. In practice if we can expose the silicon in the sun we get the same result of the silicon solar cell. A good utility for power transistors ( TO3 types ) or metallic encapsulation is recycling , using them in a solar panel .
These solar panels transistors are of low energy efficiency but serve as experiments , besides being simple to manufacture. In order to make the solar cell of a transistor , we need at least one PN junction is not burnt . You can use any transistor in these conditions , but you have to take the lid off to let the silicon sample , it is he who captures sunlight and converts it into energy.
Be careful not to break the tiny filaments that connect the pins of the transistor to the silicon wafer . The more transistors used for this is the 2N3055 used in power amplifiers and power supplies . But nothing prevents other transistors are used. Even 2n3055 transistor has gain difference from one to another , so always use the middle to do the calculations .
We saw in the article How to Make a Solar Panel using Transistor 2N3055 a way to turn a simple calculator in a solar calculator with 2n3055 transistors.
From practice, each 2N3055 transistor with one of its working joints, exposed to direct sunlight, is capable of producing 500 millivolts and 5.5 milliamps. Draw down a solar panel with based on transistor 2n3055 cells, it is able to generate 6 volts and its current is around 40 mA. 48 transistors are connected in four blocks of 12. Transistors should preferably be connected in series, with the base connected to the collector, but we talk with another base emitter junction may also be used, only in that case that the output is smaller, can see the table below.
Solar cell:
Types of Links
The junction V W
Base + Emitter 370mV 94uA 35uW
Base + Emitter and Collector, 325mV 215uA 70uW
Collector, Base + 340mV 265uA 90uW
Collector +, Broadcaster 28mV 65uA 1UW
Basically the connection is as follows, (+) collector with (-) for the base, or you can use the emitter and collector connected together by connecting the (+) collector with (+) from the sender to the (-) Base . Thus allowing the transistor 12 in series can produce a voltage of about 6 volts with sunlight directly on them. But when placing four blocks connected in parallel, each transistor 12 in series with the voltage remains equal to 6 volts, but the current increases.
Solar panel with diodes
In the same way it is done with transistors, it is possible to make diodes with a solar panel. The photo above is a home solar panel made of diodes, it can be made from common diodes which are encapsulated with glass. This module solar panel has 20 diodes, which provide a voltage of 2.5 Volts to 3 Volts, and its current is around 35 mA when exposed to sunlight directly.
You can vary the amounts of diodes in series and parallel, it will vary the power and intensity of a solar panel. Another tip is to use LEDs instead diodes, except that the circuit will have less efficiency.
As we speak, this is a more didactic and experimental than practical use, it's just a way to enjoy old trasistores or one of the open joints, as to generate an output of 15 watts, which is enough just to light a compact fluorescent lamp , you would need at least 5,555 transistors 2n3055 for this