Theory and design of electrical and electronic circuits

493 Pages·2001·3.52 MB·english

by  Tait E.

Theory and Design of
Electrical and Electronic Circuits
Index
Introduction
Chap. 01 Generalities
Chap. 02 Polarization of components
Chap. 03 Dissipator of heat
Chap. 04 Inductors of small value
Chap. 05 Transformers of small value
Chap. 06 Inductors and Transformers of great value
Chap. 07 Power supply without stabilizing
Chap. 08 Power supply stabilized
Chap. 09 Amplification of Audiofrecuency in low level class A
Chap. 10 Amplification of Audiofrecuenciy on high level classes A and B
Chap. 11 Amplification of Radiofrecuency in low level class A
Chap. 12 Amplification of Radiofrecuency in low level class C
Chap. 13 Amplifiers of Continuous
Chap. 14 Harmonic oscillators
Chap. 15 Relaxation oscillators
Chap. 16 Makers of waves
Chap. 17 The Transistor in the commutation
Chap. 18 Multivibrators
Chap. 19 Combinationals and Sequentials
Chap. 20 Passive networks as adapters of impedance
Chap. 21 Passive networks as filters of frequency (I Part)
Chap. 22 Passive networks as filters of frequency (II Part)
Chap. 23 Active networks as filters of frequency and displaced of phase (I Part)
Chap. 24 Active networks as filters of frequency and displaced of phase (II Part)
Chap. 25 Amplitude Modulation
Chap. 26 Demodulación of Amplitude
Chap. 27 Modulation of Angle
Chap. 28 Demodulation of Angle
Chap. 29 Heterodyne receivers
Chap. 30 Lines of Transmission
Chap. 31 Antennas and Propagation
Chap. 32 Electric and Electromechanical installations
Chap. 33 Control of Power (I Part)
Chap. 34 Control of Power (II Part)
Chap. 35 Introduction to the Theory of the Control
Chap. 36 Discreet and Retained signals
Chap. 37 Variables of State in a System
Chap. 38 Stability in Systems
Chap. 39 Feedback of the State in a System
Chap. 40 Estimate of the State in a System
Chap. 41 Controllers of the State in a System
Bibliography
Theory and Design of
Electrical and Electronic Circuits

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Introduction

Spent the years, the Electrical and Electronic technology has bloomed in white hairs; white
technologically for much people and green socially for others.
To who writes to them, it wants with this theoretical and practical book, to teach criteria of
design with the experience of more than thirty years. I hope know to take advantage of it because, in
truth, I offer its content without interest, affection and love by the fellow.

Eugenio Máximo Tait

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Chap. 01 Generalities

Introduction
System of units
Algebraic and graphical simbology
Nomenclature
Advice for the designer

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Introduction

In this chapter generalizations of the work are explained.
Almost all the designs that appear have been experienced satisfactorily by who speaks to them.
But by the writing the equations can have some small errors that will be perfected with time.
The reading of the chapters must be ascending, because they will be occurred the subjects
being based on the previous ones.

System of units

Except the opposite clarifies itself, all the units are in M. K. S. They are the Volt, Ampere,
Ohm, Siemens, Newton, Kilogram, Second, Meter, Weber, Gaussian, etc.
The temperature preferably will treat it in degrees Celsius, or in Kelvin.
All the designs do not have units because incorporating each variable in M. K. S., will be
satisfactory its result.

Algebraic and graphical simbology

Often, to simplify, we will use certain symbols. For example:

— Parallel of components 1 / (1/X + 1/X + ...) like X // X //...
1 2 1 2
„
‡ £
— Signs like " greater or smaller" (), "equal or different " (= ), etc., they are made of
form similar to the conventional one to have a limited typesetter source.

In the parameters (curves of level) of the graphs they will often appear small arrows that
indicate the increasing sense.
In the drawn circuits when two lines (conductors) are crossed, there will only be connection
between such if they are united with a point. If they are drawn with lines of points it indicates that
this conductor and what he connects is optative.

Nomenclature

A same nomenclature in all the work will be used. It will be:

— instantaneous (small) v
— continuous or average (great) V
— effective (great) V or Vef
— peak Vpicoor vp

— maximum Vmax
— permissible (limit to the breakage) VADM

Advice for the designer

All the designs that become are not for arming them and that works in their beginning, but to only
have an approximated idea of the components to use. To remember here one of the laws of
Murphy: " If you make something and works, it is that it has omitted something by stop ".
The calculations have so much the heuristic form (test and error) like algoritmic (equations)
and, therefore, they will be only contingent; that is to say, that one must correct them until reaching
the finished result.
So that a component, signal or another thing is despicable front to another one, to choose among
them 10 times often is not sufficient. One advises at least 30 times as far as possible. But two
cases exist that are possible; and more still, up to 5 times, that is when he is geometric (52 = 25),
that is to say, when the leg of a triangle rectangle respect to the other is of that greater magnitude
or. This is when we must simplify a component reactive of another pasive, or to move away to us of
pole or zero of a transference.
As far as simple constants of time, it is to say in those transferences of a single pole and that is
excited with steps being exponential a their exit, normally 5 constants are taken from time to arrive
in the end. But, in truth, this is unreal and little practical. One arrives at 98% just by 3 constants
from time and this magnitude will be sufficient.
As far as the calculations of the permissible regimes, adopted or calculated, always he is advisable
to sobredetermine the proportions them.
The losses in the condensers are important, for that reason he is advisable to choose of high value
of voltage the electrolytic ones and that are of recognized mark (v.g.: Siemens). With the ceramic
ones also always there are problems, because they have many losses (Q of less than 10 in many
applications) when also they are extremely variable with the temperature (v.g.: 10 [ºC] can change
in 10 [%] to it or more), thus is advised to use them solely as of it desacopled and, preferably,
always to avoid them. Those of poliester are something more stable. Those of mica and air or oil in
works of high voltage are always recommendable.
When oscillating or timers are designed that depend on capacitiva or inductive constant of times,
he is not prudent to approach periods demarcated over this constant of time, because small
variations of her due to the reactive devices (v.g.: time, temperature or bad manufacture, usually
changes a little the magnitude of a condenser) it will change to much the awaited result.

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Chap. 02 Polarization of components

Bipolar transistor of junction (TBJ)
Theory
Design
Fast design
Unipolar transistor of junction (JFET)
Theory
Design
Operational Amplifier of Voltage (AOV)
Theory
Design

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Bipolar transistor of junction (TBJ)

Theory

Polarizing to the bases-emitter diode in direct and collector-bases on inverse, we have the
model approximated for continuous. The static gains of current in common emitter and common
bases are defined respectively

b
= h = h = I / I ~ h = h (>> 1 para TBJ comunes)
21E FE C B 21e fe
a
= h = h = I / I ~ h = h (~< 1 para TBJ comunes)
21B FB C E 21b fb

La corriente entre collector y base I es de fuga, y sigue aproximadamente la ley
CB
The current between collector and bases I it is of loss, and it follows approximately the law
CB
I = I (1 - eVCB/VT) ~ I
CB CB0 CB0

where

V = 0,000172 . ( T + 273 )
T
I = I . 2 DT/10
CB CB0(25ºC)

D
with T the temperature jump respect to the atmosphere 25 [ºC]. From this it is then

D
T = T - 25

¶I / ¶T = ¶I / ¶DT ~ 0,07. I . 2 DT/10
CB CB CB0(25ºC)

On the other hand, the dependency of the bases-emitter voltage respect to the temperature, to
current of constant bases, we know that it is

¶ ¶
V / T ~ - 0,002 [V/ºC]
BE

The existing relation between the previous current of collector and gains will be determined now

a
I = I + I = I + I
C CE CB E CB
b b b
I = I + I = I + I = ( I + I ) + I ~ ( I + I )
C CE CB BE CB BE CB CB BE CB
b a a
= / ( 1 - )
a b b
= / ( 1 + )

Next let us study the behavior of the collector current respect to the temperature and the
voltages

D ¶ ¶ D ¶ ¶ D ¶ ¶ D
I = (I /I ) I + (I /V ) V + (I /V ) V +
C C CB CB C BE BE C CC CC

¶ ¶ D ¶ ¶ D
+ (I /V ) V + (I /V ) V
C BB BB C EE EE

of where they are deduced of the previous expressions
DI = 0,07. I . 2 DT/10 DT
CB CB0(25ºC)
D D
V = - 0,002 T
BE

V - V = I (R + R ) + V + I R
BB EE B BB EE BE C EE
I = [ V - V - V + I (R + R ) ] / [ R + (R + R ) b -1 ]
C BB EE BE B BB EE E BB EE
S = (¶I /¶I ) ~ (R + R ) / [ R + R b -1 ]
I C CB BB EE EE BB
S = (¶I /¶V ) = (¶I /¶V ) = - (¶I /¶V ) = - 1 / ( R + R b -1 )
V C BE C EE C BB E BB
¶ ¶
(I /V ) = 0
C CC

being

DI = [ 0,07. 2 DT/10 (R + R )( R + R b -1 )-1 I +
C BB EE EE BB CB0(25ºC)
+ 0,002 ( R + R b -1 )-1 ] DT + ( R + R b -1 )-1 (DV - DV )
EE BB E BB BB EE

Design

Be the data

D
I = ... V = ... T = ... I = ... R = ...
C CE Cmax C

From manual or the experimentation according to the graphs they are obtained

b
= ... I = ... V = ... ( ~ 0,6 [V] para TBJ de baja potencia)
CB0(25ºC) BE
and they are determined analyzing this circuit

//
R = R R
BB B S
V = V . R (R +R )-1 = V . R / R
BB CC S B S CC BB B
D D . /
V = V R R = 0
BB CC BB S
D
V = 0
EE

R = R
EE E

R = R
CC C

and if to simplify calculations we do

b
R >> R /
E BB

us it gives

S = 1 + R / R
I BB E
S = - 1 / R
V E
DI = ( S . 0,07. 2 DT/10 I - S . 0,002 ) . DT
Cmax I CB0(25ºC) V

and if now we suppose by simplicity

D D
I >> S . 0,002 . T
Cmax V

are

D D
R = ... >> 0,002 . T / I
E Cmax
R [ ( DI / 0,07. 2 DT/10 I . DT ) - 1 ] = ... > R = ... << b R = ...
E Cmax CB0(25ºC) BB E

D D
being able to take a I smaller than I if it is desired.
C Cmax
Next, as it is understood that