Basics concept of : Transistor

1 - Introduction to Transistor

1.1 - Structure of Transistor. (Transistor)

Three layers of semiconductor transistors coupled together to form two connections
PN junction, if the order transplant PNP Transistor It is convenient, if
Order transplant NPN transistors we get the opposite. in terms of composition
Diode Transistor equivalent of two opposite game.

Transistor Structure

• 
  
  Three semiconductor layers are joined into three poles, the middle layer called
  the original pole, denoted B (Base), very thin semiconductor layers B and concentration
  low impurities.


• 
  
  Two external semiconductor layer is connected to the emitter (
  Emitter), abbreviated as E, and drain or collector (Collector)
  abbreviated as C, E and C semiconductor region having the same type of semiconductor (type N or P)
  but the size and concentration of different impurities should not permutation for
  several are.

1.2 - Operating Principles of Transistor.

* Considering the operation of NPN transistors.

Survey circuit principles
of NPN transistor

• 
  
  We grant a one-way source into two poles U CE C and E in which the (+) pole sources in C and (-) pole input E.


• 
  
  DC power supply U BE traverse limit switches and return lines to the poles B and E, in which the pole (+) on foot B, pole (-) on the leg E.


• 
  
  When the switch is opened, it was found that, although the poles C and E
  Power was still no current flows through the hub CE (at
  This line I C = 0)


• 
  
  When the switch is closed, connections are biased PN thus has a current flows from (+) source through switch U BE => line through the R term => over affair BE Pole (-) form the first line B


• 
  
  Even when the current I B appears => also instantly stream C ran through connections I make a bulb light CE, and strong C line many times I line I B


• 
  
  So obviously I C flows entirely dependent on the current I B and depend upon a formula.

I C = β.I B

• 
  
  In it I C is the line running through the hub CE


• 
  
  I B is the line running through the hub BE


• 
  
  β is the gain of the Transistor

Explanation: When a voltage U CE but electrons and holes can not pass connections PN junction to form an electric current, the appearance of lines I BE
by P in polar semiconductor layer is very thin and the concentration B-doped low, so some
free electrons from the semiconductor layer N (pole E) crossing adjacent to the layer
Semiconductor P (pole B) greater than the amount of the hole a lot, a fraction
Some of the electronic world in which holes form first line B while the majority of electronic pole gravitate toward C under the effect of voltage U CE => forming line I run through Transistor CE.

* Considering the operation of PNP Transistor.

The operation of PNP Transistor Transistor NPN quite similar but the polarity of the power source U and U BE CE opposite. C Series I go from E to C also stream I go from E to B. B

2 - Symbols and shape of the Transistor

2.1 - Symbols & Transistor shape.

Symbol of Transistor

Transistor Transistor small production capacity of large

2.2 - Symbol (on themselves Transistor)
*
Currently on the market there are many types of water production Transistor
but is most commonly used output transistors of Japan, America and the Middle
country.

• 
  
  Transistor Japan: usually denoted A ..., B ..., C ..., D ... Example A564, B733, C828, D1555
  in which the transistors denoted A and B is conveniently PNP Transistor longer
  denoted C and D is the reverse NPN transistor. the
  Transistor A and C often have small capacity and high operating frequencies
  Transistor B and D also often have large capacity and frequency of work
  lower than.


• 
  
  US-manufactured transistor. often denoted 2N ... eg 2N3055, 2N4073 etc ...


• 
  
  Transistor produced by China:
  Start with number 3, followed by two letters. Most said official letters
  bulbs: Font A and B are conveniently ball, letters C and D are balls backwards, letters
  Monday said characteristics: X and P is holding the frequency, A and G are high gloss
  frequency. The digits in order after only product. Example: 3CP25,
  3AP20 etc ..

2.3 - How to identify a foot E, B, C of transistors.

• 
  
  With the kind of small transistors, the legs C and B order, depending on the country and cut the ball out but left leg if E always let Transistor as shown below


• 
  
  If the Japanese production due Transistor: Transistor eg C828, A564, the C leg in the middle, on the right leg B.


• 
  
  If the Chinese production, Transistor leg B in the middle, on the right foot C.


• 
  
  However, some transistors are produced clones are
  This unordered => I used to know the exact measurements
  using a multimeter.

Transistor small capacity.

• 
  
  With large capacity type Transistor (as shown below), the most common are the order of the leg: the left is positive B, C and pole in the middle of the extreme right is E.

Transistor large capacity often
Ordered as on foot.

* Measure B and C define leg

• 
  
  With the small transistors are common in the legs E
  so my left foot just identify B and C is inferred foot leg
  again.


• 
  
  To watch x1Ω ladder, put a probe fixed to each
  foot, two foot switch to the other rod rest, if several needles up =
  the leg with the foot rods fixed set B, if a fixed clock que que
  Transistor reverse black cumin, fennel Transistor is a red rod conveniently ..

3. Test Method Transistor

Transistor
when operations might damage due to many reasons, such as damaged by heat
, humidity, thus increasing the voltage source or the quality of itself
Transistor, Transistor to check you remember their structures.

Anatomy of Transistor

• 
  
  Check Transistor NPN similar reverse check
  two common game diode anode pole, pole B common is, if measured from B to C
  and B to E (black rod in B) are equivalent as measured upon two diode
  pm => needle up, all other cases needles measuring up.


• 
  
  Check PNP Transistor Similar conveniently check
  Diode General match Katot two poles, pole B common point of Transistor, if
  measured from B to C and B to E (red rods in B) are equivalent as measured two
  positive diode => needle up, all other measuring metal case
  not up.


• 
  
  Contrary to the above is broken Transistor.


• 
  
  Transistor may be damaged in the case.
  
  * Measured from B to E positively or from B to C => needles
  not to the transistor off or off BC BE
  * Measured from B to E from B to C or needles on both directions is short or probe BE or BC.
  * Measured between C and E on the short-CE metal.

* The illustrations as measured test transistors.

Transistor measurements that are good.

• 
  
  Measurements above illustration: First look at
  I know Transistor symbols on the ball backwards, and the
  Transistor feet respectively ECB (based on the name Transistor). <review the determination leg Transistor>


• 
  
  Step 1: Prepare the meter to clock in an elevator x1Ω


• 
  
  Step 2 and Step 3: Measure the positive BE and BC => the needle up.


• 
  
  Step 4 and Step 5: Measure opposite BE and BC => needles up.


• 
  
  Step 6: Measure between C and E needles up


• 
  
  => Football good.

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Said measurements Transistor short-BE

• 
  
  Step 1: Prepare.


• 
  
  Step 2: Measure the needle upon between B and E on = 0 Ω


• 
  
  Step 3: Measure between B and E reverse needles up = 0 Ω


• 
  
  => Football convolution BE

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

Said measurements broken ball BE

• 
  
  Step 1: Prepare.


• 
  
  Steps 2 and 3: Measure both directions between B and E needles up.


• 
  
  => Football definitive BE

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Measurements showed the ball short-CE

• 
  
  Step 1: Prepare.


• 
  
  Step 2 and 4: Measuring in both directions between C and E needles up = 0 Ω


• 
  
  => Football convolution CE


• 
  
  Where measured between C and E needles up a bit is CE detectors.

4 - The technical specifications of the Transistor

4.1 - The technical specifications of the Transistor

• Maximum currents: A limitation of transistor currents, overcome this limitation Transistor line will be corrupted.


• Maximum voltage: The voltage of the transistor limits placed on poles CE, pass transistor voltage limits will be breached.


• Ton cutoff: The frequency limits that normal working Transistor, reached this frequency the gain of the transistor is reduced.


• Gain: A conversion ratio of line I CE How many times larger than the line I BE


• Maximum capacity: When operating a manufacturing Transistor dissipation P = U CE. I CE if capacity exceeds the maximum capacity of the Transistor Transistor will be damaged.

4.2 - Some special Transistor.

* Transistor number (Digital Transistor): Transistor Transistor numbers composed as often but foot B is fighting another few dozen k resistor

Some commonly used Transistor
used in the switch, logic circuits, control circuits, when the active
it may take action directly apply 5V in order to control foot B
lamp breaks open.

Transistor illustration of Digital Applications

* Symbol: Transistor
Digital signatures are often DTA ... (dền agreement),
DTC ... (reverse lights), KRC ... (vice lamps) KRA ... (lights
agreement), RN12 ... (reverse lights), RN22 ... (light through), UN ...., KSR ...
. Example: DTA132, DTC 124 etc ...

* Transistor capacity line (capacity horizontal)

Transistor large capacity
commonly known as oysters. Rows, scallop resource is designed vv..cac
to control the high pressure or pulse transformer operating resources, we
often have high operating voltage and withstand large flow.
The oysters of manufacturing lines (color televisions) have played more often diode
padded pole in parallel with CE.

Oysters capacity color line in Televisions

5 - Polarized to Transistor

5.1 - Power supply for Transistor (Vcc - the supply voltage)

To use one transistor in the circuit must grant
giving it a power supply, depending on the purpose of using that power is granted
Transistor directly or through resistors, coils v v ... Source
Transistor Vcc power for the convention was positive source for CE.

Transistor power supply Vcc to reverse and conveniently

• 
  
  We see that if the reverse NPN transistor, the source Vcc is positive (+), if the Vcc PNP Transistor is upon the sound source (-)

5.2 - The bias (polarization) for Transistor.

* The disasters: the level
a power source in the leg B (over or bias) to put transistors on
operational readiness state, ready to amplify the signals
although very small.

* Why must the new natural ready for Transistor it work?: To understand this let us consider two diagrams above:

• 
  
  Above are two circuit uses transistors to amplify
  signal, a vacuum circuit B is not bias and a vacuum circuit B is
  bias through RDT.


• 
  
  The source signal amplification typically included in the minutes
  very small (from 0,05V to 0,5V) when inserted into the foot B (no lights
  bias) the signals are not enough to create the line I BE (characteristics PN connection lines must have run past the new 0,6V) => so there is no line I CE => Rg = 0V voltage drop on and output voltage pins C = Vcc


• 
  
  In diagram 2, transistors RDT bias => I BE line, putting small signals into the vacuum B => make line I BE increases or decreases => also line I CE
  increases or decreases, pressure drop across Rg also change => and outputs
  It obtained an analog input signal amplitude but larger.

=> Conclusion: The natural (or polarization) means creating an electric current I BE initially, an initial pressure drop across Rg to when there is a weak signal source on pole B, line I BE will increase or decrease => I CE line also increase or decrease => leads to pressure drop across Rg also increase or decrease => and this pressure drop is a 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 resistor potentiometer

In order to amplify the signal sources different strengths and weaknesses, then
bias circuit is often used to add resistance potentiometer RPA from B down fighting
Mass.

Bias circuit resistor potentiometer RPA

* Bias circuit with feedback.
Was
resistive bias circuit from the output match (pole C) to the input (pole B)
This circuit works by increasing stability for the operation amplifier circuit.