eldas2015b - 4 - aplikasi dioda

7/26/2019 Eldas2015b - 4 - Aplikasi Dioda

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Chapter 3 Diode Circuits

3.3 Applications of Diodes


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Bulk Resistant : Contoh: IN4001 Vforward = 0.93V & I = 1A(Bulk r esistance antara P-N)

rd= V2V1 rd=

I2I1

Karena dioda komponen non linier, maka resistance keseluruhan bervariasiMisal pada IN 914

Forward Resistance: Reverse Resistance:

Mendekati breakdown

resistance menurun

Diode Resistance


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b) Contoh

Diode Load Line

Load Line


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5

Half Wave Rectifier

Ideal :

Vp(out)= Vp(in)

Frequency :

fout= fin

DC :

VDC = Vp/

= 0,318Vp

2nd Approximation :

Vp(out)= Vp(in)-0.7V


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6

Half Wave Rectifier : Contoh


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Full Wave Rectifier

VDC = 2Vp/

= 0,636Vpfout= 2fin


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8

Diode Bridge Rectifier

VDC = 2Vp/ = 0,636Vp & fout= 2fin


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FULL WAVE Vs HALF-WAVE RECTIFIER


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10

Summary Unfiltered Rectifier


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Filtered Rectifier: Choke-input


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Filtered Rectifier: Capacitor


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13

Summary of Rectifier


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CH3 Diode Circuits 14

Voltage Regulator

The ripple created by the rectifier can be unacceptable tosensitive load; therefore, a regulator is required to obtain avery stable output.

Three diodes operate as a primitive regulator.


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Voltage Regulation With Zener Diode

Voltage regulation can be accomplished with Zener diode.

Since rd is small, large change in the input will not be

reflected at the output.

inD

D

out

V

Rr

rV

1


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Evolution of AC-DC Converter


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Limiting Circuits

The motivation of having limiting circuits is to keep thesignal below a threshold so it will not saturate the entirecircuitry.

When a receiver is close to a base station, signals are largeand limiting circuits may be required.


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Input/Output Characteristics

Note the clipping of the output voltage.


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Limiting Circuit Using a Diode:

Positive Cycle Clipping

As was studied in the past, the combination of resistor-

diode creates limiting effect.


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Negative Cycle Clipping


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Positive and Negative Cycle Clipping


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General Voltage Limiting Circuit

Two batteries in series with the antiparalle diodes control

the limiting voltages.


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Untai Pemangkas (Clipper)

Dioda digunakan sebagai pemangkas sehingga

sebagian gelombang terpangkas.


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Non-idealities in Limiting Circuits

The clipping region is not exactly flat since as Vin

increases, the currents through diodes change, and so

does the voltage drop.


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Capacitive Divider

inout VV inout V

CC

CV

21

1


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Waveform Shifter: Peak at -2Vp

As Vin increases, D1 turns on and Vout is zero.

As Vin decreases, D1 turns off, and Vout drops with Vin from

zero. The lowest Vout can go is -2Vp, doubling the voltage.


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Waveform Shifter: Peak at 2Vp

Similarly, when the terminals of the diode are switched, a

voltage doubler with peak value at 2Vp can be conceived.


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Voltage Doubler

The output increases by Vp, Vp/2, Vp /4, etc in each input

cycle, eventually settling to 2 Vp.


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Pengganda Tegangan


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Lanjutan


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Another Application: Voltage Shifter


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Voltage Shifter (2VD,ON)


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Untai Penjepit (Clamper)

Menambahkan komponen DC kepada masukan

gelombang AC


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Diode as Electronic Switch

Diode as a switch finds application in logic circuits anddata converters.


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Diode Implementation of OR Gate

The circuit above shows an example of diode-implementedOR gate.

Vout can only be either VA or VB, not both.


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Untai Pensaklaran (Switching)

eldas2015b - 4 - aplikasi dioda

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