Dr. IT Solutions Forum

Wednesday, 6 May 2015

Basic concept of : Metal-oxide-semiconductor field-effect transistors (MOSFETs)

1. About Mosfet

Field Effect Transistor Mosfet's (M etal O F ield E Xide S emiconductor ransistor ffect T) is a special Transistor geometry and other operations with conventional transistors, which I already knew, Mosfet with active principles based on performance applications from schools to generate electricity, the components have large input impedance prefer to amplify the weak signal sources, Mosfet is used extensively in the power circuit monitor, computer source.

Field Effect Transistor Mosfet

2. Structure and symbols of Mosfet.

Symbols and pinout equivalent
Between Mosfet and Transistor

* Composition of the Mosfet.

Channel Mosfet vice composed of P

G: Gate called the gate

S: Source pole called source

D: Drain called drain

Mosfet cocoon N have two pieces of semiconductor type P placed on the semiconductor N, the two layers are insulated by a layer PN SiO 2 two pieces of semiconductor P is connected to the positive pole D and S, N semiconductor platform is connected to thin layer above then into positive sign G.

Mosfet resistor between the pole S pole G and between G with pole pole D is extremely large, and the resistance between the extreme poles D and S depend on the voltage difference between the extreme poles G and S (U GS)

When the voltage U GS = 0, the resistor R DS very large, the voltage U GS> 0 => magnetic effects caused by resistor R DS makes decrease, the voltage U GS greater the smaller the resistor R DS .

3. Operating principle of Mosfet

Test circuit.

Experiment card activity Mosfet

Experiment: DC Power U D over a lightbulb D at D and S poles of Mosfet Q (Conveniently for Mosfet reverse polarity) we see no light bulb means that no current through the leg pole DS G do not have electricity.

When the switch K1 closed, the source U G GS poles inlet voltage U GS> 0V => Q1 led light => light bulb D.

When K1 disconnect switch, voltage across the capacitor C1 area (ceramic capacitor) maintains the lamp Q guide => demonstrate no positive current through GS.

When the switch K2 is closed, integrated voltage across the capacitor C1 decreased by 0 => U GS = 0V => light off

=> From the above experiments it was found that: the voltage applied to pins do not generate G GS lines as in conventional transistors, but this voltage is only generated magnetic field => resistor R DS makes reduced.

4. Measure check Mosfet

A Mosfet is better: As the impedance between G and S and between G and D with resistance equal to infinity (needles to measure both directions) and when G has been freed, the electrical impedance between D and S is infinity.

Check the following steps:

Measure check Mosfet see better backwards.

Step 1: Prepare to scale x1K W

Step 2: Go to G one charge (to the black in G que que red in S or D)

Step 3: After loading the G an electric charge is measured between D and S (D que que red to black in S) => needles going up.

Step 4: Short-G to D or G to S to exit power vacuum G.

Step 5: After power vacuum drainage DS G measured as step 3 needles up.

=> The result is so good Mosfet.

Measure test shows a short, reverse Mosfet

Step 1: To watch ladder x 1K W

Between G and S measured between the G and D or if the needle up = 0 W is short

Measured between D and S which both dimensions measure up = 0 W alloy is short-DS

5. The application of Mosfet in practice

Mosfet in pulsed source of Monitor

Mosfet is used as a source of light Monitor

In the pulsed source of Monitor or computers, people often use pairs of IC components is Mosfet oscillators and lights, ranging from IC can generate square pulses are brought to the foot of the Mosfet G, at the time of pulse voltage> 0V => Mosfet light guide, the pulse oscillation = 0V Mosfet interrupt => Such oscillations generated will control for continuous switching Mosfet formed continuously variable electric current running through the primary winding => generate varying magnetic field induction to the secondary coil => for the output voltage us.

* Measure check Mosfet circuit.
When checking in-circuit Mosfet, we just need to scale x1 W and measure between D and S => If 1 clockwise to reverse the needle does not measure up => is normal Mosfet, if both clockwise up = 0 W is Mosfet short-DS.

6. Mosfet common lookup table

Instructions:

Channel type: P-Channel: the agreement Mosfet, N-Channel Mosfet is reverse.

Specification: Example: 3A, 25W: Maximum DS line and maximum capacity.

STT	Notation	Channel type	Specification
1	2SJ306	P-Channel	3A, 25W
2	2SJ307	P-Channel	6A, 30W
3	2SJ308	P-Channel	9A, 40W
4	2SK1038	N-Channel	5A, 50W
5	2SK1117	N-Channel	6A, 100W
6	2SK1118	N-Channel	6A, 45W
7	2SK1507	N-Channel	9A, 50W
8	2SK1531	N-Channel	15A, 150W
9	2SK1794	N-Channel	6A, 100W
10	2SK2038	N-Channel	5A, 125W
11	2SK2039	N-Channel	5A, 150W
12	2SK2134	N-Channel	13A, 70W
13	2SK2136	N-Channel	20A, 75W
14	2SK2141	N-Channel	6A, 35W
15	2SK2161	N-Channel	9A, 25W
16	2SK2333	N-FET	6A, 50W
17	2SK400	N-Channel	8A, 100W
18	2SK525	N-Channel	10A, 40W
19	2SK526	N-Channel	10A, 40W
20	2SK527	N-Channel	10A, 40W
21	2SK555	N-Channel	7A, 60W
22	2SK556	N-Channel	12A, 100W
23	2SK557	N-Channel	12A, 100W
24	2SK727	N-Channel	5A, 125W
25	2SK791	N-Channel	3A, 100W
26	2SK792	N-Channel	3A, 100W
27	2SK793	N-Channel	5A, 150W
28	2SK794	N-Channel	5A, 150W
29	BUZ90	N-Channel	5A, 70W
30	BUZ90A	N-Channel	4A, 70W
31	BUZ91	N-Channel	8A, 150W
32	BUZ 91A	N-Channel	8A, 150W
33	BUZ 92	N-Channel	3A, 80W
34	BUZ 93	N-Channel	3A, 80W
35	BUZ 94	N-Channel	8A, 125W
36	IRF 510	N-Channel	5A, 43W
37	IRF 520	N-Channel	9A, 60W
38	IRF 530	N-Channel	14A, 88W
39	IRF 540	N-Channel	28A, 150W
40	IRF 610	N-Channel	3A, 26W
41	IRF 620	N-Channel	5A, 50W
42	IRF 630	N-Channel	9A, 74W
43	IRF 634	N-Channel	8A, 74W
44	IRF 640	N-Channel	18A, 125W
45	IRF 710	N-Channel	2A, 36W
46	IRF 720	N-Channel	3A, 50W
47	IRF 730	N-Channel	5A, 74W
48	IRF 740	N-Channel	10A, 125W
49	IRF 820	N-Channel	2A, 50W
50	IRF 830	N-Channel	4A, 74W
51	IRF 840	N-Channel	8A, 125W
52	IRF 841	N-Channel	8A, 125W
53	IRF 842	N-Channel	7A, 125W
54	IRF 843	N-Channel	7A, 125W
55	IRF 9610	P-Channel	2A, 20W
56	IRF 9620	P-Channel	3A, 40W
57	IRF 9630	P-Channel	6A, 74W
58	IRF 9640	P-Channel	11A, 125W
59	IRFI 510G	N-Channel	4A, 27W
60	IRFI 520G	N-Channel	7A, 37W
61	IRFI 530g	N-Channel	10A, 42W
62	IRFI 540G	N-Channel	17A, 48W
63	IRFI 620	N-Channel	4A, 30W
64	IRFI 630g	N-Channel	6A, 35W
65	IRFI 634G	N-Channel	6A, 35W
66	IRFI 640G	N-Channel	10A, 40W
67	IRFI 720G	N-Channel	3A, 30W
68	IRFI 730G	N-Channel	4A, 35W
69	IRFI 740G	N-Channel	5A, 40W
70	IRFI 820g	N-Channel	2A, 30W
71	IRFI 830G	N-Channel	3A, 35W
72	IRFI 840G	N-Channel	4A, 40W
73	IRFI 9620G	P-Channel	2A, 30W
74	IRFI 9630G	P-Channel	4A, 30W
75	IRFI 9640G	P-Channel	6A, 40W
76	IRFs 520	N-Channel	7A, 30W
77	IRFs 530	N-Channel	9A, 35W
78	IRFs 540	N-Channel	15A, 40W
79	IRFs 620	N-Channel	4A, 30W
80	IRFs 630	N-Channel	6A, 35W
81	IRFs 634	N-Channel	5A, 35W
82	IRFs 640	N-Channel	10A, 40W
83	IRFs 720	N-Channel	2A, 30W
84	IRFs 730	N-Channel	3A, 35W
85	IRFs 740	N-Channel	3A, 40W
86	IRFs 820	N-Channel	2A-30W
87	IRFs 830	N-Channel	3A-35W
88	IRFs 840	N-Channel	4A-40W
89	IRFs 9620	P-Channel	3A-30W
90	IRFs 9630	P-Channel	4A-35W
91	IRFs 9640	P-Channel	6A-40W
92	J177 (2SJ177)	P-Channel	0.5A-30W
93	J109 (2SJ109)	P-Channel	20mA, 0.2W
94	J113 (2SK113)	P-Channel	10A-100W
95	J114 (2SJ114)	P-Channel	8A-100W
96	J118 (2SJ118)	P-Channel	8A
97	J162 (2SJ162)	P-Channel	7A-100W
98	J339 (2SJ339)	P-Channel	25A-40W
99	K30A / 2SK304 / 2SK30R	N-Channel	10mA, 1W
100	K214 / 2SK214	N-Channel	0.5A, 1W
101	K389 / 2SK389	N-Channel	20mA, 1W
102	K399 / 2SK399	N-Channel	10-100
103	K413 / 2SK413	N-Channel	8A
104	K1058 / 2SK1058	N-Channel
105	K2221 / 2SK2221	N-Channel	8A-100W
106	MTP6N10	N-Channel	6A-50W
107	MTP6N55	N-Channel	6A-125W
108	MTP6N60	N-Channel	6A-125W
109	MTP7N20	N-Channel	7A-75W
110	MTP8N10	N-Channel	8A-75W
111	MTP8N12	N-Channel	8A-75W
112	MTP8N13	N-Channel	8A-75W
113	MTP8N14	N-Channel	8A-75W
114	MTP8N15	N-Channel	8A-75W
115	MTP8N18	N-Channel	8A-75W
116	MTP8N19	N-Channel	8A-75W
117	MTP8N20	N-Channel	8A-75W
118	MTP8N45	N-Channel	8A-125W
119	MTP8N46	N-Channel	8A-125W
120	MTP8N47	N-Channel	8A-125W
121	MTP8N48	N-Channel	8A-125W
122	MTP8N49	N-Channel	8A-125W
123	MTP8N50	N-Channel	8A-125W
124	MTP8N80	N-Channel	8A-75W

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.

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

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

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

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.

Basic concept of : semiconductor Diode

1 - Semiconductors

1.1 - What are Semiconductors?
Matter
semiconductor materials to produce various kinds of semiconductor devices such as
Diodes, transistors, IC, which I had seen in the electronics Day
today.

Semiconductors are substances with characteristics intermediate between
conductors and insulators, in chemical terms, the semiconductor is
4 E substances in the outermost layer of atoms. That is the nature
Germanium (Ge) and silicium (Si)

From the initial semiconductor (pure) one must
create two types of semiconductor transistors are N-type and P-type semiconductors, then
puzzle pieces N and P type semiconductors obtained the diode or transistor.

Si and Ge are 4 valence, ie the outermost layer 4
e, can in pure Si atoms (Ge) linked together
covalent links shown below.

Pure semiconductors.

1.2 - Semiconductors Category N

* When you mix a small amount of chemotherapy with 5 as phosphorus (P) in nature
Semiconductor silicon atom is linked to 4 P Si atom by association
covalent, only 4 atoms of phosphorus electron involved in affiliate
and residual electron and become a free electron => Semiconductors time
became redundant electronic (negatively charged) and semiconductors called N (
Negative: negative).

Semiconductors N

1 .3 - Semiconductors Category P

Conversely, when we added a small amount of chemotherapy with 3 as Indium
(In) in the first semiconductor Si atoms will link Indium
with 4 Si atoms according covalent link and link missing
E => become holes (positively charged) and is
semiconductors called P.

Semiconductors P

2 - Diode (LED) Semiconductor

2.1 - Contiguous P - N and structure of semiconductor diode.
At
had been two semiconductors are P and N, if two semiconductor compound according to
an adjacent P - N It is a diode, adjacent P characterized -N
: In the contact surface, the excess electrons in the semiconductor N diffusers
to the semiconductor P to fill the holes => forms a layer Ion
neutral electricity => Ion class domain constitutes insulation between
two semiconductor.

Contacts P - N => Diode Configuration.

* In the image on the contacts P - N and also the structure of the semiconductor diode.

Symbols and shape of the semiconductor diode.

2.2 - Sub-biased for the diode.
At
our positive voltage (+) to anode (the semiconductor P) and negative voltage (-)
in Katot (semiconductor region N), while under the effect of electric interactions
pressure, shrinking domain insulator when the voltage reaches the gap between the two poles
0,6V (with diode type Si) or 0,2V (with diode type Ge), the area
domain area Insulation reduces zero => Diode start conductivity. If
continue to increase the voltage source, a current through the diode increases rapidly but differences
voltage difference between the poles of diode does not increase (remain 0,6V)

Diode (Si) biased - When Dode guide
gim upon current voltage at 0,6V

Curve of forward voltage across the diode

* Conclusion: When Diode (type Si)
is biased, if bias voltage <0,6V is no
Diode line passing, if biased voltage gain = 0,6V then crossing the line
Diode then current through the diode voltage drop upon increasing but remains
in value 0,6V.

2.3 - for Diode Reverse Polarity.

When the diode reverse polarity power supply means (+) in Katot (sold
guide N), source (-) to anode (semiconductor P), under voltage interaction
in contrast, the wider region and insulated to prevent electrical current through
contiguity, the diode can withstand reverse voltages very large
about 1000V, the new diode is punctured.

Diode only fires when the reverse bias voltage increases> = 1000V

2.4 - Measurement methods test Diode

Measure check Diode

Set in an elevator x 1Ω clock, put two strips at the ends Diode, if:

Conveniently measuring rods into anode black, red rods in Katot => needle up, reversing the needle does not measure up is => Diode good

If measuring both clockwise up = 0Ω => was short-Diode.

If the needle does not measure up positively => Diode is broken.

In the diode D1 measurements on good, diode D2 and D3 short-cuts

If that measure to scale back into diode 1KΩ metal is still up a little diode detectors.

2.5 - Application of semiconductor diode.

* Due to the one-dimensional conductors should Diode
often used in the rectifier into an AC source
dimensional detector circuits, circuit bias gim for transistor operation
action. in rectifier diode can be integrated into a diode bridge
form.

Diode rectifier bridge in AC.

3 - Types Diode

3.1 - Zener Diode
* Components:
Zener diode has a structure similar to the diode normally but there are two layers of semiconductor P
- N coupled together, Zener Diode applied in polarization mode
in contrast, when the forward bias diode zener diode as often but when feces
gim zener diode will reverse bias voltage to a fixed value
recorded on diode.

Shape Zener diode (Dz)

Symbols and applications of zener diode in the circuit.

The diagram above illustrates the application of Dz, source voltage source U1 is changed, voltage regulator diode Dz, R1 is becoming limited line.

We see that the source U1> Dz Dz, shall always fixed on whether sources U1 change.

When sources U1 change the line back through Dz change, reverse flow through Dz limit value of about 30mA.

Usually people use source U1> 1.5 => 2
Dz and installation times or R1 current limit so that the largest reverse flow through Dz
<30mA.

If U1 <Dz when pressure on Dz U1 change also changes
If U1> Dz when U1 change => constant pressure on Dz.

3.2 - Thu optical diode. (Photo Diode)
Diode
optical receiver operate in reverse polarity mode, with a piece of bark diode
glass to light in connection P - N, reverse current through the diode
proportional to the intensity of light falling on diode.

Symbol of Photo Diode

Illustrating the operation of Photo Diode

3.3 - Luminescence Diode (Light Emiting Diode: LED)
Diode
development phang light emitting diode is being biased, voltages
Work of LED 1.7 => 2,2V line ranges from 5mA to pass Led
20mA

Led used to make light sources, decorative flashlight, power status. etc ...

LED light emitting diode

3.4 - Diode varicap (variable capacitance diode)
Diode variable capacitance diode capacitance is like capacitor, and the capacitance change when we change put into diode reverse voltage.

What variables into applications of diode varicap (V D)
the resonant circuit

In the picture above when we adjust VR dimmable voltage
Diode varicap placed opposite change of diode capacitance change
=> Changed the resonance frequency of the circuit.

Variable capacitance diode is used in the color television channel, in the tuned circuit resonant frequency by voltage.

3.5 - Diode pulse
In
the source of the output pulse of the pulse transformer, we must use Diode
pulses to the rectifier. pulse diode diode is working at high frequencies of several
tens of KHz, conventional diode rectifier irreplaceable position
pulse diode, but backward pulse diode can substitute for location
ordinary diode, diode pulse diode costs often many times higher.

Feature, Diode pulse shape is not any different with Diode
Often, however, the pulse Diode often dashed mark or ring
marked by two rounds

Symbol of pulsed Diode

3.6 - Diode detector.

A type of small notebooks glass diode and diode contacts called for
the contact surface between the semiconductor P - N at a point to avoid electricity
parasitic capacitance, diode detector used in high-frequency circuits
to separate the signal wave.

3.7 - Diode adapter.

Diode is to face adapter used in the rectifier AC 50Hz
, This diode is usually 3 types 1A, 2A and 5A.

Diode 5A adapter