At the beginning of the 20th century, when
computers began to be produced, they were gigantic. Today, however, there has been the discovery
of transistors that make them small enough to take them on our knees and fit them in
our palms with phones or tablets. In addition, thanks to transistors, processors
that offer much faster operation have been developed. A transistor is an electronic circuit element
that regulates current or voltage flow and acts as a switch or amplifier for electronic
signals. It was invented in 1947 and quickly replaced
the vacuum tube as an electronic signal conditioner. It consists of a layer of doped semiconductor
materials such as silicon and germanium, each of which can carry a current. The subject of this video is not the structure
and history of transistors, but after a small introduction about transistors, we can move
on to our main topic. You may know or have heard of transistors
such as BJT, MOSFET, JFET, NPN, N-Channel and many more. But you may have trouble distinguishing them. If so, this lesson is for you. At the end of this video, we will basically
learn that all three pins circuit elements are not transistors, how transistors are classified
and how we can distinguish them. Transistors are classified into two groups,
BJT and FET. These expressions come from abbreviations
formed from the initials of their English names. BJT comes from the acronym Bipolar Junction
Transistor while FET comes from the abbreviation Field Effect Transistor. The task of both transistors is to provide
current control or voltage amplification as a switch. If we talk briefly about the differences between
them, BJTs control current and current, while FETs control voltage and current. BJTs are quickly affected by temperature,
while FETs are less affected by temperature. As such, BJTs degrade quickly, while FETs
are more durable and long-lasting. Therefore, BJTs are generally preferred in
low-current hobby electronic applications, while FETs are mostly preferred in low-voltage
commercial applications. Also, BJTs have a low switching speed, while
FETs have a high switching speed. BJT is divided into two groups as NPN and
PNP. Symbols are as they are here. FETs are divided into two groups as JFET and
MOSFET. While JFETs are produced in two types as N-Channel
and P-Channel only as Depletion Mode, MOSFETs are of two types as Depletion and Enhancement
Mode. Each of these is produced in two types as
N-Channel and P-Channel. This is the basic classification of transistors,
friends. Here, you may have a question whether other
three pins circuit elements such as thyristor and TRIAC are not transistors. These are the other power electronics circuit
elements that we see here are basically developed using BJTs and FETs. Now let's look at these other 3 pins power
electronics circuit elements that we can mix with transistors. Thyristors are generally used for fast switching
duty in DC power electronics circuits. Thyristors are similar to transistors. They also have 3 pins. Pin names are Anode, Cathode and Gate. These also occur in the form of PNPN. TRIACs are similar to thyristors. The abbreviation TRIAC comes from the initials
of the English words Triode for Alternating Current. It is actually formed by the reverse connection
of two thyristors to each other. As such, they are used for switching purposes
in AC power electronics circuits. Pin names differ from thyristor. These have 3 pins and the pin names are as
you can see here. IGBT, on the other hand, is a power electronics
circuit element that is formed by developing the best features of MOSFET and BJT transistor. These are also 3 pins. IGBT comes from the abbreviation of the words
Insulated Gate Bipolar Transistor. It is used in many areas for switching purposes. IGBTs, which can act as diodes when necessary,
or as triacs or transistors when necessary, are used extensively, especially in UPSs that
require high switching speed. The other circuit element that is most confused
with transistors is the voltage regulator. Voltage regulators are also 3-pin. But it is not a transistor. They ensure that the voltage is fixed at the
output at values such as 5V, 9V, 12V. They do not act as amplification or switching
like transistors. On our channel, there are videos about their
basic working logic, friends. I will try to make new ones. You can view them later if you wish. As you can see, new circuit elements are emerging
as a result of the rapid development of technology. As such, most of them are similar to each
other and we have difficulty in distinguishing them. So, how do we understand whether a 3-pin circuit
element made of semiconductors that we see on an electronic board is a BJT, MOSFET, JFET,
voltage regulator or another circuit element. For this, we will write the numbers and letters
written on it and add a datasheet expression to the end and search on google. We will reach the information papers with
the technical specifications presented to us by the companies that produce this circuit
element. For example, when we look at the datasheet
information of the widely used BC546/547/548 BJT transistor, we can reach the information
that it is NPN and the pin naming. Here we look at the surface with the name
written while detecting the pins. We identify the pins according to the names
corresponding to the numbers 1,2 and 3. For example, in this BJT transistor, the left
pin corresponds to Collector, the middle pin to Base and the right pin to Emitter. In addition, here we can reach a lot of information
about the maximum operating parameters and electrical characteristics. Likewise, in the datasheet information of
the widely used 2N5638 JFET transistor, we can access the information that it is N-Channel,
the pin name and location information, the maximum operating aperture degrees and a lot
of information about its electrical characteristics. When we look at the information of the IRFZ44
transistor, which is also very widely used, we can see that it is an N-Channel Enhancement
Mode MOSFET. In addition, from its technical features,
there is information that current can be controlled up to 49A and voltage can be controlled up
to 55V with this MOSFET. Thus, we can reach information about the circuit
elements that are stuck in our minds and whose properties we do not know, by looking at the
datasheet information in this way. In this way, you can choose the appropriate
circuit element for the circuit you will make with a little research. Apart from these, there are many different
circuit elements similar to the transistor. I have tried to show the most used ones here. I hope it was helpful and you liked it. Hope to see you in the next video. Goodbye.
