User manual

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build machines, calculators or entire computers with such
basic circuits.
Transistors
A transistor contains a silicon crystal. Silicon (Si) is found
in normal quartz sand in large quantities (quartz = silicon
oxide). It belongs to the group of semiconductors; these
substances neither conduct electric current as well as met-
als nor do they have the properties of insulating materials
such as glass or rubber. In order to achieve a very specific
conductivity, the smallest amounts of other substances
are added to the pure silicon. Depending on the nature
of these substances, N-silicon or P-silicon are obtained.
Your transistor has three layers: NPN. Other types feature a
different layer sequence, namely PNP. They work similarly,
but the current direction differs.
Our transistor is a BC547B transistor. Using
this type reference, you can select exactly
the right type, which by the way is pro-
duced by a number of companies. Or you
can search for the datasheet on the inter-
net. The datasheet contains crucial proper-
ties and parameters. In a nutshell: This
NPN transistor works with a voltage of 50 V
and a current of 100 mA. Plus, it can ampli-
fy the current by 200 times at least.