The post Broadcast Routing(dynamic) appeared first on ece4uplp.
]]>i.e, sending a packet to all destinations simultaneously is called Broadcasting.
Different methods of Broadcasting:
so this is least desirable one.
In this technique each packet contains a list of destinations (or) a bit map for those destinations.
when a packet arrives at a router, the router checks all the output lines it requires. The router generates a new copy of the packet for each output line after sufficient number of hops each packet will carry only one destination.
i.e, multi destination routing is like separately addressed packets (to B,C,D,E & D) must follow the same route one of them pays full fare and rest are free.
A spanning tree is a subset of subnet that includes all the routers but contains no loops.
if each router knows which of it’s lines belong to spinning tree then it broadcasts packet to all the lines except the one it arrived on.
This is efficient method in terms of Band width usage but problem is to maintain the knowledge of all the nodes of spanning tree at a routes.
Consider a subnet and it’s sink tree for router I as root node and how reverse path algorithm works in figure (C)
on the first hop I sends packets to F, H, J & N. on the second hop eight packets are generated among them 5 are given to preferred paths indicated as circles (A,D,G,O,M)
of the 6 packets generated in third hop only 3 are given to preferred paths (C,E & K) the others are duplicates.
in the fourth hop to B and L after this broadcasting terminates.
advantages of reverse path forwarding:
The principle is : if a packet arrives on a line if it is preferred one to reach source it gets forwarded.
if it arrives on a line that is not preferred one that packet is discarded as a duplicate.
ex:
when a packet arrives at ‘L’ the preferred paths are N and P so it forward the packets to both N and P and if a packet arrives at ‘K’ , there the preferred path is M and N is not preferred so it forwards packet to M and discards to N.
This is reverse path forwarding.
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]]>The post Asynchronous Transfer Model(ATM) appeared first on ece4uplp.
]]>Asynchronous Transfer Model is another important connection oriented Network.
Why we call it asynchronous is most of the transmission in telephone systems is synchronous (closed tied to a clock) but ATM is not such type.
ATM was designed in 1990’s, it was the cell ray protocol designed by the ATM forum and was adopted by ITUT.
Design goals:
The problems associated with existing networks:
The design goals come into picture for ATM, since there exists some problems that are associated with the existing systems.
Frame Networks:
Before ATM we have data communications at DLL are based on frame switching and frame networks .
i.e, different protocols use frames of varying size (frame has data and header). If header size is more than that of actual data there is a burden so some protocols have enlarged the size of data unit relative to the header.
if there is no data in such cases there is a wastage , so there is to provide variable frame sizes to the users.
Mixed N/w Traffic:
If there exists variable frame sizes
suppose we have two networks generating frames of variable sizes that is N/W 1 is connected to line 1 and the frame is X. N/W 2is connected to line 2 and of having 3 frames of equal sizes A,B,C are connected to a TDM.
If X has arrived a bit earlier than A,B,C (having more priority than X) on the output line . The frames has to wait for a time to move on to the output line, this causes delay for line 2 N/W.
i.e, Audio and video frames are small so mixing them with conventional data traffic often creates unacceptable delays and makes shared frame links unusable for audio and video information.
but we need to send all kinds of traffic over the same links.
Cell Networks:
so a solution to frame internet working is by adopting a concept called cell networking.
In a cell N/W we use a small data unit of fixed size called cell so all types of data are loaded into identical cells and are multiplexed with other cells and are routed through the cell N/W.
because each cell is small and of same size the problems associated with multiplexing different sized frames are avoided.
Asynchronous TDM:
ATM uses asynchronous TDM hence the name Asynchronous Transfer Model.
i.e, it multiplexes data coming from different channels. it also uses fixed size slots called cells.
ATM Mux’rs fill a slot with a cell from any input channel that has a cell and slot is empty if there is no cell.
ATM architecture:
ATM was going to solve all the world’s networking and telecommunications problems by merging voice, data, cable TV, telex,telegraph…… and everything else into a single integrated system that could do everything for everyone.
i.e, ATM was much successful than OSI and is now widely used in telephone system for moving IP packets.
ATM is a cellswitched N/W the user access devices are connected through a userto N/W interface (UNI) to the switches inside the N/W. The switches are connected through N/WtoN/W interface (NNI) as shown in the following figure
Virtual Connection:
two end points is accomplished through transmission paths (TP’s), Virtual Paths (VP’s) and Virtual Circuits (VC’s)
ATM Virtual Circuits:
Since ATM N/w’s are connectionoriented, sending data requires a connection , first sending a packet to setup the connection.
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]]>The post Parallel Polarization appeared first on ece4uplp.
]]>Parallel polarization means field lies in the XZplane (y=0) that is the plane of incidence, the figure illustrates the case of parallel polarization
then the incident and reflected fields is given by
now the reflected wave is
since
let’s find out then by using the equation , .
and the transmitted fields in the second medium is
where .
Transmission coefficient:
as and also that the tangential components of and are continuous at the boundary z=0.
, since
(1)+(2) implies
.
Reflection coefficient:
from EQN (1)
after simplification
.
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]]>The post Surface impedance appeared first on ece4uplp.
]]>The surface impedance may be defined as the ratio of the tangential component of the electric field at the surface of the conductor to the current density (linear) which flows due to this electric field.
given as (or) .
is the Electric field strength parallel to and at the surface of the conductor.
and is the total linear current density which flows due to .
The represents the total conduction per meter width flowing in this sheet.
Let us consider a conductor of the type plate, is placed at the surface y=0 and the current distribution in the ydirection is given by
Assume that the depth of penetration () is very much less compared with the thickness of the conductor.
from ohm’s law
.
then .
(or) .
we know that
for good conductors .
then
.
therefore the surface impedance of a plane good conductor which is very much thicker than the skin depth is equal to the characteristic impedance of the conductor.
This impedance is also known s input impedance of the conductor when viewed as transmission line conducting energy into the interior of metal.
when the thickness of the plane conductor is not greater compared to the depth of penetration , reflection of wave occurs at the back surface of the conductor.
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]]>The post oblique incidence appeared first on ece4uplp.
]]>Now consider the situation that is more general case that is the oblique incidence.
In this case the EM wave (incident wave) not strikes normally the boundary. i.e, the incident wave is not propagating along any standard axes (like x,y and z).
Therefore EM wave is moving in a random direction then the general form is
it is also in the form .
then is called the wave number vector (or) the propagation vector.
and is called the position vector (from origin to any point on the plane of incidence) , then the magnitude of is related to according to the dispersion.
.
.
.
.
i. and are mutually orthogonal.
ii. and lie on the plane .
then the field corresponding to field is .
Now choose oblique incidence of a uniform plane wave at a plane boundary.
the plane defined by the propagation vector and a unit normal vector to the boundary is called the plane of incidence.
the angle between and is the angle of incidence.
both the incident and reflected waves are in medium 1 while the transmitted wave is in medium 2 .
Now,
.
the wave propagates
(1) indicates that all waves are propagating with same frequency. (2) and (3) shows that the tangential components of propagation vectors be continuous.
implies since .
implies .
now velocity .
then from Snell’s law , where and are the refractive indices of the two media.
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]]>The post Poynting theorem appeared first on ece4uplp.
]]>Poynting theorem is used to get an expression for propagation of energy in a medium.
It gives the relation between energy stored in a timevarying magnetic field and the energy stored in timevarying electric field and the instantaneous power flow out of a given region.
EM waves propagates through space from source to destination. In order to find out power in a uniform plane wave it is necessary to develop a power theorem for the EM field known as poynting theorem.
The direction of power flow is perpendicular to and in the direction of plane containing and .
i.e, it gives the direction of propagation .
Watts/m^{2} (or) VA/m^{2}.
Proof:
from Maxwell’s equations
the above equation has units of the form current density Amp/m^{2}. When it gets multiplied by V/m. The total units will have of the form power per unit volume.
Amp/m^{2} , Volts/m.
Amp. Volt/m^{3} Watts/m^{3} Power/volume.
by using the vector identity
then
.
from the equation of Maxwell’s
by using the vector identity
if
from EQN(I) ,
by integrating the above equation by over a volume
by converting the volume integral to surface integral
.
the above equation gives the statement of Poynting theorem.
Poynting theorem:
It states that the net power flowing out of a given volume is equal to the time rate of decrease in the energy stored with in that volume V and the ohmic losses.
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]]>The post Lag compensator appeared first on ece4uplp.
]]>A Lag compensator has a Transfer function of the form
, where and
PoleZero Plot of Lag compensator:
i.e, the pole is located to the right of the zero.
Realization of Lag compensator as Electrical Network:
The lag compensator can be realized by an electrical Network.
Assume impedance of source is zero and output load impedance to be infinite .
The transfer function is
after simplification
after comparing the above equation with the transfer function of lag compensator has a zero at and has a pole at .
from the pole and .
therefore the transfer function has a zero at and a pole at .
.
the values of the three parameters , and C are determined from the two compensator parameters and .
using the EQN(II)
, .
there is an additional degree of freedom in the choice of the values of the network components which is used to set the impedance level of the N/w.
the gain is
D.C gain at is which is greater than 1.
Let the zerofrequency gain as unity, then the Transfer function is .
Frequencyresponse of Lag compensator:
Note:“lag” refers to the property that the compensator adds positive phase to the system over some appropriate frequency range.
, let .
the frequency response of lag compensator is
at .
has a slope +20 dB/decade with corner frequency .
slope is 20 dB/decade with corner frequency .
to find at which frequency the phase is minimum , differentiate w.r to and equate it to zero.
implies , which is invalid because .
.
, at this lead compensator has minimum phase given by
implies .
.
at , .
Choice of :
Any phase lag at the gain cross over frequency of the compensated system is undesirable.
To prevent the effects of lag compensator , the corner frequency of the lag compensator must be located substantially lower than the of compensated system.
In the high frequency range , the lag compensator has an attenuation of dB, which is used to obtain required phase margin.
The addition of a lag compensator results in an improvement in the ratio of control signal to noise in the loop.
high frequency noise signals are attenuated by a factor , while lowfrequency control signals under go unit amplification (0 dB gain).
atypical value of .
Procedure for bodeplot of a lead compensator:
Step 1: Sketch the Bodeplot of the uncompensated system with the gain k. Set the value of k according to the steadystate error requirement.
Measure the gain cross over frequency and the phase margin of uncompensated system.
Step 2: find at which phase angle of uncompensated system is
+ given Phase Margin+ .
is a good assumption for phaselag contribution.
Step 3: find gain of the uncompensated system at and equate it to 20 log () and then find .
Step 4: choose the upper corner frequency of the compensator to one octave to one decade below and find value.
Step 5: Calculate phase lag of compensator at , if it is less than go to next step.
Step 6: Draw the Bode plot of compensated system to meet the desired specifications.
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]]>The post Lead Compensator appeared first on ece4uplp.
]]>A Lead compensator has a Transfer function of the form
, where and
Polezero plot of Lead compensator:
i.e, the pole is located to the left of the zero.
Realization of Lead compensator as an Electrical Network:
The lead compensator can be realized by an electrical Network.
Assume impedance of source is zero and output load impedance to be infinite .
The transfer function is
after simplification
by comparing this equation with the transfer function of lead compensator has a zero at and the pole is .
from the pole and .
therefore the transfer function has a zero at and a pole at .
.
the values of the three parameters , and C are determined from the two compensator parameters and .
using the EQN(II)
, .
there is an additional degree of freedom in the choice of the values of the network components which is used to set the impedance level of the N/w.
the gain is
D.C gain at is which is less than 1.
attenuation is used to determine the steady state performance.
while using a lead N/w , it is important to increase the loop gain by an amount of .
A lead compensator is visualized as a combination of a N/w and an amplifier.
Note:“lead” refers to the property that the compensator adds positive phase to the system over some appropriate frequency range.
Frequencyresponse of a lead compensator:
, let .
the frequency response of lead compensator is
to find at which frequency the phase is maximum , differentiate w.r to and equate it to zero.
implies , which is invalid because .
.
, at this lead compensator has maximum phase given by
implies .
.
at , .
when there is a need for phase leads of more than , two cascaded lead networks are used where each N/w provides half of the required phase.
for phase leads more than , decreases sharply and if single N/w is used will be too low.
Choice of :
In choosing parameters of compensator depends on and C . The value may be anything but for there is a constraint. It depends on inherent noise in Control systems.
from the lead N/w , it’s been observed that the high frequency noise is amplified by while low frequencies by unity.
more (or) less should not be less than 0.07.
Procedure for bodeplot of a lead compensator:
Step 1: Sketch the Bodeplot of the uncompensated system with the gain k. Set the value of k according to the steadystate error requirement.
Measure the gain cross over frequency and the phase margin of uncompensated system.
Step 2: using the relation
Additional phase lead required = specified phase margin Phase Margin of uncompensated system.
is a margin of safety required by the fact that the gain cross over frequency will increase due to compensation.
for example : is a good assumption for 40 dB/decade.
(or) 60 dB/decade.
Step 3: Set the maximum phase of the lead compensator Additional phase lead required and compute .
Step 4: Find the frequency at which the uncompensated system has a gain of dB, which gives the new gain cross over frequency.
with as the gain cross over frequency the system has a phase margin of .
where as with as the gain cross over frequency the system has a phase margin of .
Step 5: Now . find the value of and the transfer function of lead compensator .
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]]>The post Introduction to Root Locus appeared first on ece4uplp.
]]>while in the analysis of a given system, the very first investigation that needs to be made is whether the system is stable or not?
However, the determination of stability of a system is necessary but not sufficient.
A stable system with low damping is also unwanted.
a design problem in which the designer is required to achieve the desired performance for a system by adjusting the location of its close loop poles in the Splane by varying one (or) more system parameters.
The Routh’s criterion obviously does not help much in such problems.
for determining the location of closedloop poles one may resort to the classical techniques of factoring the characteristic equation and determining it’s roots.
when the degree is higher (or) repeated calculations are required as a system parameter is varied for adjustments.
a simple technique, known as the root locus technique, for finding the roots of the ch.eqn introduced by W.R.Evans.
This technique provides a graphical method of plotting the locus of the roots in the Splane as a given system parameter is varied from complete range of values (may be from zero to infinity).
The roots corresponding to a particular value of the system parameter can then be located on the locus (or) value of the parameter for a desired root location can be determined from the locus.
Root Locus:
ch. equation is
let
To find the whether the roots are on the Root locus (or) not
They have to satisfy ‘2’ criteria known as
Magnitude criterion:
the magnitude criterion states that will be a point on root locus, if for that value of s
i.e,
Angle criterion:
where q=0,1,2……….
if is odd multiple of , a point s on the root locus, if is odd multiple of at of , then that point is on the root locus.
Root Locus definition:
The locus of roots of the Ch. eqn in the Splane by the variation of system parameters (generally gain k) from to is known as Root locus.
It is a graphical method
to Inverse Root Locus
to Direct Root Locus
generally Root Locus means Direct Root Locus.
m= no .of zeros
n= no.of poles
from magnitude criterion
The open loop gain k corresponding to a point on Root Locus can be calculated
product of length of vectors from open loop poles to the point /product of length of vectors from open loop zeros to the point .
from the Angle criterion,
i.e,( sum of angles of vectors from Open Loop zeros to point )(sum of angles of vectors from Open Loop poles to point)
where q=0,1,2………
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]]>The post Inductance of a Coaxial cable, Solenoid & Toroid appeared first on ece4uplp.
]]>Consider a coaxial cable with inner conductor having radius a and outer conductor of radius b and the current is flowing in the cable along zaxis in which the cable is placed such that the axis of rotation of the cable coincides with zaxis.
the length of the coaxial cable be d meters.
we know that the between the region is
and since
as , here the flux linkage
where Total flux coming out of the surface
Since the magnetic flux will be radial plane extending from to and to .
Henries.
Inductance of a Solenoid:
Consider a Solenoid of N turns and let the current flowing inside it is ‘I’ Amperes. The length of the solenoid is ‘l’ meters and ‘A’ is its cross sectional area.
– Total flux coming out of solenoid.
flux linkage
, from the definition
As B is the Magnetic flux density given
from EQN(I) ,
because
The field strength H of a solenoid is
EQN (II) becomes
from the inductance definition
Henries.
Inductance of a Toroid:
Consider a toroidal ring with Nturns and carrying current I.
let the radius of the toroid be ‘R’ and the total flux emerging be
then flux linkage
the magnetic flux density inside a toroid is given by
where A is the cross sectional area of the toroid then
Henries.
if the toroid has a height ‘h’ , inner radius and outer radius then its Inductance is Henries.
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]]>The post Classification (or) topologies of feedback Amplifiers appeared first on ece4uplp.
]]>The first part represents the type of sampling at the output .
and the second part represents the type of Mixing at the input
For any Amplifier circuit we require
Classification of feedback Amplifiers is also known as feedback Topologies.
VoltageSeries feedback Connection:
at i/p side connection is Series and at o/p side connection used is Shunt since o/p is collected is voltage.
Series connection increases i/p impedance and Voltage at the o/p indicates a decrease in o/p impedance.
i.e, and .
CurrentSeries feedback Connection:
Series connection increases i/p impedance and Current at the o/p indicates an increase in o/p impedance.
i.e, and .
VoltageShunt feedback Connection:
In this connection, both i/p and o/p impedance decreases .
i.e, and .
CurrentShunt feedback Connection:
Shunt connection decreases i/p impedance and Current at the o/p indicates an increase in o/p impedance.
i.e, and .
Effect of negative feedback on different topologies:
Type of f/b 
Voltage gain

Band Width with f/b  i/p impedance 
o/p impedance 
VoltageSeries  decreases  increases  increases  decreases 
CurrentSeries  decreases  increases  increases  increases 
VoltageShunt  decreases  increases  decreases  decreases 
CurrentShunt  decreases  increases  decreases  increases 
Similarly negative feedback decreases noise and harmonic distortion for all the four topologies.
Note: for any of the characteristics in the above table, increase ‘s shown by multiplying the original value with and decrease ‘s shown by dividing with .
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]]>The post continuity equation appeared first on ece4uplp.
]]>consider a closed surface S with a current density , then the total current I crossing the surface S is given by the volume V
The current coming out of the closed surface is
since the direction of current is in the direction of positive charges, positive charges also move out of the surface because of the current I.
According to principle of conversation of charge, there must be decrease of an equal amount of positive charge inside the closed surface.
therefore the time rate of decrease of charge with in a given volume must be equal to the net outward current flow through the closed surface of the volume.
By Divergence theorem
implies
for a constant surface the derivative becomes the partial derivative
this is for the whole volume.
for a differential volume
, which is called as continuity of current equation (or) Point form (or) differential form of the continuity equation.
This equation is derived based on the principle of conservation charge states that there can be no accumulation of charge at any point.
for steady (dc) currents
from . The total charge leaving a volume is the same as total charge entering it. Kirchhoff’s law follows this equation.
This continuity equation states that the current (or) the charge per second, diverging from a small volume per unit volume is equal to the time rate of decrease of charge per unit volume at every point.
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]]>The post Effect of negative feedback on Band width of an Amplifier appeared first on ece4uplp.
]]>Proof: Consider an amplifier with gain ‘A’
Now the frequency response of the amplifier is as shown in the figure. Frequency response curve means gain (dB) Vs frequency (Hz)
the frequency response of an amplifier consists of three regions
Gain in low frequency region is given as,
open loop gain,
– frequency,
– lower cut off frequency, where Gain in constant region is .
Gain in Highfrequency region is .
In lowfrequency region:
since open loop gain in lowfrequency region is and gain with feedback is
From EQN(I) after substituting in the above equation
Now by dividing the whole expression with
, where and
for example lower cutoff frequency implies is decreasing with negative feedback.
In Highfrequency region:
Gain with out feed back in High frequency region is
Now Gain with negative feed back is
Substituting in the above equation
Now by dividing the whole expression with
, where and
for example lower cutoff frequency implies is increasing with negative feedback.
In Midfrequency region:
Gain with out feed back is
and the gain with negative feed back is
With out feedback  With feedback 
lower cutoff frequency is  lower cutoff frequency , increases 
upper cutoff frequency is  upper cutoff frequency is 
BW =  increases 
Thus negative feedback decreases lower cutoff frequency and increases upper cutoff frequency.
Over all gain decreases with negative feedback and Band Width increases.
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]]>The post Full Wave Rectifier appeared first on ece4uplp.
]]>FWR converts a.c voltage into pulsating DC in twohalf cycles of the applied input signal.
Here we use a Transformer, whose secondary winding has been split equally into two half waves with a common center tapped connection ‘c’.
This configuration results in each diode conducting in turn when it’s anode terminal is positive with respect to Center point ‘c’ of the Transformer.
Working of Full Wave Rectifier:
During positive half cycle of applied i/p signal
i.e, Diode is Forward Biased and is Reverse Biased , under this condition the equivalent circuit is as shown below
, when there is no diode resistance.
Similarly the conditions of diodes will be reversed for the negative half cycle of i/p signal.
i.e, Diode is Reverse Biased and is Forward Biased , under this condition the equivalent circuit is and output voltage is .
the i/p and o/p wave forms are as shown below
FWR is advantageous compared to HWR in terms of its efficiency and ripple factor.
Ripple Factor ():
to find out and of output signal
,
,
,
.
and .
now the ripple factor results to be
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]]>The post Timedomain representation of SSBSC signal appeared first on ece4uplp.
]]>, where is InPhase component of S(t) obtained by
i. Multiplying S(t) with .
ii. and passing the product through a LPF with suitable cutoff frequency.
By finding the Fourier Transform of inphase component
after restricting the signal between
Similarly is the quadrature phase component of s(t), obtained by multiplying S(t) with and by passing the resultant signal through a LPF .
By finding the Fourier Transform of Qphase component
after restricting the signal between
Now Let’s assume S(f) is the required frequency spectrum of SSBSC signal when only USB has been transmitted.
i.e,
from the above figure,
one can obtain , by shifting the signal S(f) towards right by and left by
Now by adding and
from the above figure, results to be
from the frequency spectrum of , the timedomain representation turns out to be
Similarly,
The resultant signals and
from the frequency spectrum of turns out to be
since Signum function is
when expressed in terms of Signum function
By using Hilbert transform of m(t) , the timedomain representation turns out to be
From EQN’s (I) and (II) , the timedomain representation of SSBSC signal results
.
similarly, SSB signal when only LSB has been transmitted
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]]>The post Analog ElectronicCircuits Lab appeared first on ece4uplp.
]]>Expt1iiZener Diode Characteristics
Expt2Full Wave Rectifier with and without filters
Expt3Common Emitter Characteristics
Expt6single stage CE Amplifierfrequency response
Expt8Noninverting Amplifier
Expt9Differentiator and Integrator using opamp
Expt10square and triangular wave generators
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]]>The post Input and Output characteristics of transistor in Common Base Configuration appeared first on ece4uplp.
]]>Input characteristics in Common Base configuration means input voltage Vs input current by keeping output voltage as constant.
i.e, Vs by keeping constant.
Therefore the curve between Emitter current and Emitter to Base voltage for a given value of Collector to Base voltage represents input characteristic.
for a given output voltage , the input circuit acts as a PNjunction diode under Forward Bias.
from the curves there exists a cutin (or) offset (or) threshold voltage below which the emitter current is very small and a substantial amount of Emittercurrent flows after cutin voltage ( 0.7 V for Si and 0.3 V for Ge).
the emitter current increases rapidly with the small increase in . with the low dynamic input resistance of a transistor.
i.e,
This is calculated by measuring the slope of the input characteristic.
i.e, input characteristic determines the input resistance .
The value of varies from point to point on the Nonlinear portion of the characteristic and is about in the linear region.
Output Characteristics:
Output Characteristics are in between output current Vs output voltage with input current as kept constant.
i.e,
i.e, O/p characteristics are in between Vs by keeping as constant.
basically it has 4 regions of operation Active region, saturation region,cutoff region and reachthrough region.
active region:
from the active region of operation is almost independent of
i.e,
when increases, there is very small increase in .
This is because the increase in expands the collectorbase depletion region and shortens the distance between the two depletion regions.
with kept constant the increase in is so small. transistor operates in it’s normal operation mode in this region.
saturation region:
here both junctions are Forward Biased.
Collector current flows even when (left of origin) and this current reaches to zero when is increased negatively.
cutoff region:
the region below the curve ,transistor operates in this region when the two junctions are Reverse Biased.
even though mA. this is because of collector leakage current (or) reversesaturation current (or) .
punch through/reach through region:
is practically independent of over certain transistor operating region of the transistor.
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]]>The post Early effect in Common Base Configuration appeared first on ece4uplp.
]]>In Common Base configuration in the Reverse Bias, As the voltage increases, the spacecharge width between collector and base tends to increase, with the result that the effective width of the base decreases. This dependency of Basewidth on the Collector to emitter voltage is known as the early effect.
The early effect has three consequences:
For higher values of , due to early effect the value of increases, for example changes say from 0.98 to 0.985. Hence there is a very small positive slope in the CB output characteristics and hence the output resistance is not zero.
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]]>The figure shows the experimental arrangement to observe Hall effect Now
I Current flowing in the semi conductor (xdirection)
B Applied Magnetic field (zdirection)
E Induced Electric field is along ydirection perpendicular to both I and B.
Now charge carrier electron is moving under the influence of two fields both electric field(E) and Magnetic field(B).
i.e, electron is under the influence of both E and B, E applies some force on electron similarly B.
under equilibrium
, where is the drift velocity
Electric field Intensity due to Hall effect is
is the Hall voltage between plates 1 and 2.
and d is the distance between the two plates.
In an Ntype Semi conductor, the current is due to electrons , plate 1 is negatively charged compared to plate 2.
The current density J related to charge density is
W width of the specimen, d height of the specimen.
From EQN(I) and From EQN(II)
up on multiplying with ‘d’ on both sides
from EQN(III)
, let Hall coefficient
.
Uses of Hall effect (or) Applications of Hall effect:
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