Basic Transistor

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1 - Introduction to Transistor
1.1 - Structure of Transistor. (Transistor)
Three-layer semiconductor transistors coupled together to form two connections
PN junction, if the transplant in order PNP transistors have been successful, if
transplantation in order NPN Transistor we are back. in terms of structure
Diode Transistor equivalent to two oppositely game.

Transistor Structure

• Three semiconductor layers are connected into three poles, the middle layer called
  is very original symbol B (Base), B is very thin semiconductor layers and levels
  low impurities.
• The two outer semiconductor layer is connected to the emitter (
  Emitter) abbreviated as E, and drain or collector (Collector)
  abbreviated as C, E and C semiconductor regions having the same type semiconductor (N or P type)
  but the size and concentration of impurities should be no different permutations for
  is another.

1.2 - Principle of operation of transistors.

* Considering the operation of the NPN transistor.

Circuit examined the principles 
of the NPN transistor

• We supply a DC source U CE on poles C and E in the (+) positive source in C and (-) source in positive E.
• DC Power U BE traverse limit switches and return lines on poles B and E, in which positive (+) in the leg B pole (-) to pin E.
• When the switch opens, we see that although the poles C and E
  granted power but still no current flows through the connection CE (at
  This current I C = 0)
• When the switch is closed, act upon polarization PN is therefore a current flows from (+) source via switches U BE => over the limit R => through relationship of positive BE (-) form the I B
• As soon as the I B appears => instant line also runs through the connections I C CE as light bulbs, and the C I line up many times I B
• So, obviously I C line is completely dependent on the I B and depends on a formula.

I C = β.I B

• Where I C is the line running through the act CE
• I B is the line running through each tank
• β is the gain of the transistor

Explanation: When a voltage U CE, but the electrons and holes can not pass connections to form the PN junction current, the appearance of lines I BE
by P in polar semiconductor layer B is very thin and low doping concentration, so the
free electrons from the semiconductor layer N (positive E) over layer adjacent to
semiconductor P (pole B) greater number of holes a lot, a small
of electrons into the hole that the current I B is made ​​up mostly of electrons attracted to the extreme C under the effect of voltage U CE => CE I made ​​the run through the transistor.

* Considering the operation of the PNP transistor.

The activity of PNP Transistor NPN Transistor quite similar but the polarity of the power supply CE and U BE U reverse. Series I E Cfrom B to C is the line I went from E to B.

2 - Symbol and shape of the Transistor
2.1 - The symbol & Transistor shape.

Symbols of the Transistor

Transistor Transistor small capacity of the large

2.2 - Symbol (body Transistor) 
*
Currently the market has a variety of countries producing Transistor
but the most common of the transistor of Japan, America and China
the country.

• Japanese Transistor: usually denoted as A ... B ... C ... D ... For example, A564, B733, C828, D1555
  Transistor symbols of which are A and B is a PNP Transistor agreement also
  denoted as C and D are opposite NPN Transistor. the
  Transistor A and C usually has a small and high working frequency
  Transistor B and D are the usually large and the frequency of work
  is lower.
• Transistor by U.S. producers. usually denoted as 2N ... eg 2N3055, 2N4073, etc. ...
• Transistor from China Manufacturer:
  Start with No. 3, followed by two letters. The letter said that most of
  ball: Text A and B is the ball upon, the letter C, and D is the ball back, the word
  said Monday features: X and P is the ball frequency, A and G is a high gloss
  the frequency. The numbers in the order of the product only. Example: 3CP25,
  3AP20 etc. ..

2.3 - How to determine pin E, B, C of the transistor.

• With the kind of small transistors, the order of C and B foot, depending on which country the shadow of lemon grass production, but E always left foot if you like the picture below to Transistor
• If the Japanese production Transistor: Transistor eg C828, A564 is the middle leg C, B on the right foot.
• If China is producing transistors are in the middle leg B, C on the right foot.
• However, some clones are produced Transistor
  not in this order => to know the exact method we use to measure
  with a multimeter.

The small transistor.

• Transistor With a capacity of large (see below), most have the same order is true: extreme left is B, C, and in between the extreme right is extremely E.

The most common of Transistor 
unordered pins as above.

* Measure the legs B and C determined

• With the small transistor is generally true in E
  so we just left leg identified B and C are inferred foot leg
  back.
• To scale x1Ω clock, a probe fixed on each
  foot, two foot switch to the other rod rest, if the needle on each other =
  the feet are fixed rods B is true, if que que a fixed clock
  black is the opposite Transistor, Transistor as a red stick, the agreement ..

3 - Test methods Transistor 

Transistor
when the operation can fail for many reasons, such as damage due to heat
, humidity, due to high voltage or by their own quality
Transistor to Transistor remember to check their composition.

Structure of Transistor

• Check back NPN Transistor similar test
  Match two common anode diode, is a very common point B, if measured from B to C
  and B to E (black rods in B), the measured two-diode equivalent agreement
  pm => kim up, all other metal case measuring no more.
• PNP Transistor check upon the same test
  two common game Diode Katot extreme, extreme point, that of transistor B, if
  measured from B to C and B to E (red stick on B) is equivalent to measuring the two
  positively diode => kim up, all other measured metal case
  not up.
• Contrary to the above is broken Transistor.
• Transistor may be damaged in case.
  
  * Measured from B to E positively or from B to C => kim 
  transistor is not to cut off the BE or BC 
  * Measure from B to E or from B to C to the two-way needle or probe is short BE or BC. 
  * Measured between C and E has been short needle to the CE.

* The images illustrate the measurement test transistors.

Transistor measurements for good.

• Illustration of measurements: First look
  Transistor symbols known to be on the ball backwards, and the
  foot of the ECB Transistor, respectively (based on the name Transistor). <look at the leg determined Transistor>
• Step 1: Prepare to watch the scale measuring x1Ω
• Step 2 and Step 3: Measure positively BE and BC => kim up.
• Step 4 and Step 5: Measure the opposite direction of BE and BC => no more needles.
• Step 6: Measure between C and E needles up
• => Football fine.

------------------------

Transistor measurements that has been short-BE

• Step 1: Prepare.
• Step 2: Measure the agreement between B and E = 0 Ω needle up
• Step 3: Measure the contrast between B and E = 0 Ω needle up
• => Football convolution BE

----------------------

Measurements for the ball broke BE

• Step 1: Prepare.
• Step 2 and 3: Measure both directions between B and E on the needles.
• => Football definitive BE

-------------------

Measurements showed that the ball has been short-CE

• Step 1: Prepare.
• Step 2 and 4: Measure both directions between C and E = 0 Ω needle up
• => Football convolution CE
• Where measured between C and E is a little metal detector CE.

4 - The specifications of the Transistor
4.1 - The specifications of the Transistor

• Current maximum mean current of the transistor limits, overcome the limitations of this transistor will be damaged.
• Voltage: The voltage of the transistor limits placed on the pole CE, pass transistor voltage limits will be disruptive.
• Cutoff frequency: The frequency limits of normal working Transistor, beyond this frequency the gain of the transistor is reduced.
• The gain: The rate of change of current I CE How many times larger than the I BE
• Maximum Power: When operating a transistor dissipation of P = U CE. I CE if the production exceeds the maximum capacity of the transistor, the transistor will be damaged.

4.2 - Some Transistor special.
* Transistor number (Digital Transistor): Transistor Transistor number is made ​​up as often but leg B is fighting a few tens of KΩ resistor

Transistor number of commonly used
switch in the circuit, logic circuit, control circuit, when active
action one can take direct command voltage 5V on pin B to control
light breaks open.

Illustrating the application of Transistor Digital

* Symbol: Transistor
Digital signatures are often DTA ... (amaranth agreement),
DTC ... (reverse lights), KRC ... (reverse lights) KRA ... (lights
agreement), RN12 ... (reverse lights), RN22 ... (lights upon), UN ...., KSR ...
. Example: DTA132, DTC 124, etc. ...

* Transistor capacity of the line (the horizontal production)

Transistor capacity of large
commonly known as oysters. Number of lines, number of sources, etc. .. the shell is designed
to control the transformer high-voltage pulse source or activity, we
typically have high operating voltage for the big bear.
The number of rows (color TV) usually have more diode
buffer in parallel with positive CE.

Number of TV lines in color

5 - Transistor Polarity for
5.1 - Power Supply for Transistor (Vcc - supply voltage)
To use the transistor in the circuit we need to grant
give it a power source, depending on the purpose for which power is used for
Transistor directly or through resistors, coils, etc. ... source
Transistor Vcc power for established as the maximum power for CE.

Transistor Vcc power to reverse and agree

• We see that: If the Vcc NPN transistor is opposite to the positive power (+), if the agreement PNP Transistor Vcc is the source of the negative (-)

5.2 - The natural (polarization) to Transistor.

* The natural: the level
a power source to pin B (over or bias) to put the transistor into
ready state, ready to amplify the signal
though small.

* Why it's bias transistor willing to work?: To understand this we consider the two diagrams above:

• The above circuit uses two transistors to amplify
  signal, a circuit is not true bias B and B is a vacuum circuit
  bias through the RDT.
• The source signal into the amplifier often border
  very small (from 0.05 V to 0.5 V) when put into leg B (no lights
  bias) the signal is not sufficient to create the I BE (PN fading characteristics relationship with the new 0.6 V line running through) => so I did not have the CE => drop on Rg = 0V and C = output voltage Vcc pin
• In diagram 2, RDT Transistor with bias => I have the BE, when taken in small signal pin B => do I line up or down = BE> CE line I also
  increases or decreases, the pressure drop also changes Rg => and outputs
  we obtain an analog input signal but with larger amplitude.

=> Conclusion: The natural (or polarization) that is creating an electric current I BE original, an initial drop in the Rg to the signal source is an extremely weak in B, the line will increase or decrease I BE => the CE I also raise or lower => voltage drop resulting in increased or decreased Rg => and this drop is the signal we need to get out.

5.3 - Some other mach bias.

* Bias circuit uses two different power sources.

Bias circuit uses two different power sources

* Mach bias voltage power is distributed

To amplify the signal sources of different strength, the
bias circuits typically use resistors distributed more pressure from B to RPA
Mass.

Circuit bias voltage power is distributed RPA

* A feedback circuit bias. 
Is
resistive bias circuit from the output (pole C) to the input (pole B)
This circuit has a beneficial effect on stability when operating amplifier circuit.