AB16
COMMON COLLECTOR
AMPLIFIER
Analog Lab
Experiment Board
Ver. 1.0
QUALITY POLICY
To be a Global Provider of Innovative and Affordable
Electronic Equipments for Technology Training by
enhancing Customer Satisfaction based on
Research, Modern manufacturing techniques and
continuous improvement in Quality of the products
and Services with active participation of employees.
An ISO 9001: 2000 company
94-101, Electronic Complex, Pardesipura INDORE-452010, India.
Tel.: 91-731-2570301 Fax: 91-731-2555643
AB16
Email: info@scientech.bz Web: www.scientech.bz
Scientech Technologies Pvt. Ltd.
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COMMON COLLECTOR AMPLIFIER
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TABLE OF CONTENTS
1.Introduction
4
2. Theory
6
3.Experiment
12
To study the Common Collector Amplifier (NPN) and to
evaluate :
a.
Operating Point of the Common Collector Amplifier
Voltage gain of the Amplifier AV.
b.
Input and output impedance of Amplifier.
c.
Current gain of Amplifier.
4.Datasheet
14
5.Warranty
16
6.List of Service Centers
17
7.List of Accessories with AB16
18
8. Notes
19
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INTRODUCTION
AB16 is a compact, ready to use Common Collector Amplifier experiment
board. This is useful for students to understand the functionality of common
collector amplifier and to study various operational parameters of an
transistor Amplifier. It can be used as stand alone unit with external DC
power supply or can be used with Scientech Analog Lab ST2612 which
has built in DC power supply, AC power supply, function generator,
modulation generator, continuity tester, toggle switches, potentiometer.
Model
Name
AB01
AB02
AB03
AB04
AB05
AB06
AB07
AB08
AB09
AB10
AB11
AB12
AB13
AB14
AB17
AB18
AB19
AB20
AB21
AB22
AB23
AB25
Diode characteristics (Si, Zener, LED)
Transistor characteristics (CB NPN)
Transistor characteristics (CB PNP)
Transistor characteristics (CE NPN)
Transistor characteristics (CE PNP)
Transistor characteristics (CC NPN)
Transistor characteristics (CC PNP)
FET characteristics
Rectifier Circuits
Wheatstone Bridge
Maxwell’s Bridge
De Sauty’s Bridge
Schering Bridge
Darlington Pair
Common Base Amplifier
Cascode Amplifier
RC-Coupled Amplifier
Direct Coupled Amplifier
Class A Amplifier
Class B Amplifier (push pull emitter follower)
Class C Tuned Amplifier
Phase Locked Loop (FM Demodulator & Frequency
Divider / Multiplier)
Multivibrator ( Mono stable / Astable)
F-V and V-F Converter
V-I and I-V Converter
Zener Voltage Regulator
Transistor Series Voltage Regulator
Transistor Shunt Voltage Regulator
DC Ammeter
AB28
AB29
AB30
AB31
AB32
AB33
AB35
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AB39
AB41
AB43
AB44
AB45
AB51
AB52
AB53
AB54
AB56
AB57
AB58
AB59
AB64
AB65
AB66
AB67
AB68
AB80
AB82
AB83
AB84
AB85
AB88
AB89
AB90
AB91
AB92
AB93
AB96
AB97
AB101
AB102
AB106
AB110
AB111
AB112
AB113
AB115
AB116
Instrumentation Amplifier
Differential Amplifier (Transistorized)
Operational Amplifier (Adder/Scalar)
Operational Amplifier (Integrator/ Differentiator)
Schmitt Trigger and Comparator
Active filters (Low Pass and High Pass)
Active Band Pass Filter
Notch Filter
Tschebyscheff Filter
Fiber Optic Analog Link
Owen’s Bridge
Anderson’s Bridge
Maxwell’s Inductance Bridge
RC – Coupled Amplifier with Feedback
Phase Shift Oscillator
Wien Bridge Oscillators
Colpitt Oscillator
Hartley Oscillator
RLC Series and RLC Parallel Resonance
Thevenin’s and Maximum power Transfer Theorem
Reciprocity and Superposition Theorem
Tellegen’s Theorem
Norton’s theorem
Diode Clipper
Diode Clampers
Two port network parameter
Optical Transducer (Photovoltaic cell)
Optical Transducer (Photoconductive cell/LDR)
Optical Transducer (Phototransistor)
Temperature Transducer (RTD & IC335)
Temperature Transducer (Thermocouple)
DSB Modulator and Demodulator
SSB Modulator and Demodulator
FM Modulator and Demodulator
Log and Antilog Amplifier
Crystal Oscillator (1 MHz)
Peak Detector
Voltage Follower & Precision Rectifier
Op-Amp Oscillator (Sine / Cosine)
Sample and Hold Circuit
………… and many more
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THEORY
Amplification is the process of increasing the strength of signal. An
Amplifier is a device that provides amplification (the increase in current,
voltage or power of signal) without appreciably altering the original signal.
A Bipolar transistor is frequently used as an amplifier. A bipolar transistor
is a current amplifier, having three terminals Emitter, Base, Collector. A
small current into base controls a large current flow from the collector to
emitter. The large current flow is independent of voltage across the
transistor from collector to emitter. This makes it possible to obtain a large
amplification of voltage by taking the output voltage from a resistor in
series with the collector.
Transistor can be used as an Amplifier in three configurations:
1.
Common Base
2.
Common Emitter
3.
Common Collector
Common Collector Configuration :
In this arrangement, the input signal is applied between base and collector
and the output is taken from the emitter and collector. In this arrangement
input current is base current and output current is emitter current.
Fig. 1
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Current relations in CC configurations
IE = IC + IB
IE = γ * IB + γ * ICBO
γ = IE / IB
Where
IB = Base current (input current)
IC = Collector current
IE = Emitter current (output current)
ICEO = current through collector to emitter when base is open.
γ = current amplification in CC configuration.
Operation of Common Collector amplifier :
In order to get faithful amplification, the transistor is properly DC biased.
The purpose of DC biasing is to obtain a certain DC Emitter current (IC) at a
certain DC Emitter voltage (VEC). These values of current and voltage are
called operating point (Quiescent point). To obtain DC operating point
some biasing methods are used called biasing circuits. These biasing
arrangements should be such as to operate the transistor in Active region.
The Most commonly used Biasing circuits is voltage divider method. In this
method two resistances R1 and R2 are connected across the supply voltage
VCC and provide proper biasing. A voltage divider formed by R1 and R2, and
the voltage drop across R2 forward biased the base emitter junction this
causes the base current and hence collector current flows in zero signal
condition. Resistance RE provides stabilization.
V2 = VCC * R2 / (R1 + R2)
V2 = VBE + VE
V2 = VBE + IER
IE = (V2 - VBE) / RE
IE is approx. equal to IC.
IC = (V2 - VBE) / RE
VCE = VCC - IC (RC + RE)
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Fig. 2
This method is widely used because operating point of transistor can be
made almost independent of beta (β) and provides good stabilization of
operating point.
If this circuit is used to amplify AC voltages, some more components must
be added to it.
Coupling Capacitors (C1 &C3): They are used to pass AC input signal and
block the DC voltage from the preceding circuit. This prevents DC in the
circuitry on the left of coupling capacitor from affecting the bias on
transistor. The coupling capacitor also blocks the bias of transistor from
reaching the input signal source. It is also called blocking capacitor. Bypass
Capacitors (C2): It bypasses all the AC current from the emitter to the
ground. If the capacitor C2 is not put in the circuit, the AC voltage
developed across RE will affect the input AC voltage, such a feedback is
reduced by putting the capacitor C2.
RE: It represents the load resistance is connected at the output.
In this amplifier input signal is injected in to base-collector circuit and
output signal is taken out from the emitter-collector circuit, When the
output is taken from emitter terminal of transistor this network is referred as
Emitter Follower or common collector amplifier. In this amplifier output
voltage is always less than the input signal, and output voltage is in phase
with the input voltage. The fact that output voltage follows the magnitude
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of input voltage with an in-phase relationship accounts for the terminology
"Emitter Follower".
When positive half cycle of the signal is applied then,
1.
Forward biased is increased, since Vbe is positive w.r.t. collector ie.
Ground.
2.
Base current is increased,
3.
Emitter current is increased,
4.
Drop across Re is increased,
5.
Hence output voltage is increased; consequently positive half-cycle
of the output is obtained. I.e. input and output are in phase with each
other.
Fig. 3
Operating Parameter of Common collector amplifier :
Voltage Gain :
The ratio or Output Voltage (Vo) to the input voltage (Vi) is known as
voltage amplification or voltage gain of amplifier.
Voltage Gain (AV) = VO / Vi
Input Impedance :
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It is the ratio of Input voltage (Vin) to input current (Ii)
Zin = Vin / Ii
To measure the input impedence a known resistor (Rs) is placed in series
before the input coupling capacitor and the impedence could be calculated
using the equation
Zin = Rs / (Av/Av`- l)
Where
Av = voltage gain without the resistor (Rs)
Av` = voltage gain with the resistor (Rs)
Fig. 4
Output Impedence : It is the ratio of Output voltage (Vout) to Output
Current (Io).
Zout = Vout / Io
To measure the Output impedence a known resistor (Rs) is placed from
output to ground and the output impedence could be calculated using the
equation
Zout = (Av / Av`-l) * Rs
Where
Av = voltage gain without the resistor (Rs)
Av` = voltage gain with the resistor (Rs)
Current gain :
It is the ratio of Output current ( Io) to Input current (Ii).
Ai = IO / Ii
The Current gain could be calculated using the equation
Ai = - Av * Zin / RL
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Characteristics of Common Collector Amplifier :
1.
It produces no phase reversal, i.e., input and output signals are in
phase with each other.
2.
It has voltage gain of less than 1.
3.
It has very high input impedance.
4.
It has low output impedance.
5.
It has high current gain (β + 1).
Comparisons of Amplifiers Configurations :
Type of Amplifier Circuit
Characteristic
Common
Base
Common
Emitter
Common
Collector
Phase reversal
No
Yes
No
Voltage Gain
High
Highest
Nearly Unity
Input
Impedance
Lowest
Moderate
Highest
Output
Impedance
Highest
Moderate
Lowest
Current Gain
Nearly unit
High (β)
Highest (β + 1 )
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EXPERIMENT
Objective :
To study the Common Collector Amplifier and to evaluate –
Operating Point, Voltage gain (AV), input and output impedance,
current gain of amplifier.
Apparatus required :
1.
Analog board of, AB16.
2.
DC power supply +12V external source or ST2612 Analog Lab.
3.
Digital Multimeter
4.
2 mm patch cords.
Circuit diagram :
Circuit used to study Common Collector Amplifier is shown in Fig 5.
Fig. 5
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Procedure :
1.
Connect test point 2 and test point 3, test point 4 and test point 5, test
point 6 and test point 7, using 2mm patch cords.
2.
Connect +12V dc power supply at their indicated position from
external source or ST2612 Analog Lab.
3.
Switch ON the power supply.
4.
For the measurement of Quiescent Point measure the VEC by
connecting voltmeter between test point 4 and test point 6. Measure
Emitter current (IE) by connecting ammeter between test point 6 and
test point 7.
5.
Connect a sinusoidal signal of 10mV (p-p) at 25KHz frequency at
the Test point 1 (Input of amplifier).
6.
Observe the amplified output on oscilloscope by connecting test
point 8 (output of amplifier) to oscilloscope.
7.
Calculate Voltage gain of amplifier. Connect Load resistor of 1K
ohms at the output and find the voltage gain of amplifier with load
resistor.
8.
Calculate input impedance, output impedance, current gain of
amplifier using the mentioned formulas with resistance 1 K.
Result :
Operating Point of the Common collector amplifier
IC = ______________mA
VEC =______________V
Voltage gain of the amplifier AV
=________________
Input impedance of amplifier Zin
=________________
Output Impedance of amplifier Zout =________________
Current gain of amplifier Ai
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=________________
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DATASHEET
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Scientech Technologies Pvt. Ltd.
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WARRANTY
1) We guarantee the instrument against all manufacturing defects during
24 months from the date of sale by us or through our dealers.
2) The guarantee covers manufacturing defects in respect of indigenous
components and material limited to the warranty extended to us by the
original manufacturer and defect will be rectified as far as lies within
our control.
3) The guarantee will become INVALID.
a) If the instrument is not operated as per instruction given in the
instruction manual.
b) If the agreed payment terms and other conditions of sale are not
followed.
c) If the customer resells the instrument to another party.
d) Provided no attempt have been made to service and modify the
instrument.
4) The non-working of the instrument is to be communicated to us
immediately giving full details of the complaints and defects noticed
specifically mentioning the type and sr. no. of the instrument, date of
purchase etc.
5)
The repair work will be carried out, provided the instrument is
dispatched securely packed and insured with the railways. To and fro
charges will be to the account of the customer.
DISPATCH PROCEDURE FOR SERVICE
Should it become necessary to send back the instrument to factory please
observe the following procedure:
1) Before dispatching the instrument please write to us giving fully details
of the fault noticed.
2) After receipt of your letter our repairs dept. will advise you whether it
is necessary to send the instrument back to us for repairs or the
adjustment is possible in your premises.
Dispatch the instrument (only on the receipt of our advice) securely packed
in original packing duly insured and freight paid along with accessories and
a copy of the details noticed to us at our factory address.
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LIST OF SERVICE CENTERS
1. Scientech Technologies Pvt. Ltd.
90, Electronic Complex
Pardesipura,
INDORE – 452010
2. Scientech Technologies Pvt. Ltd.
First Floor, 14, Uday Park,
NEW DELHI – 110049
3. Scientech Technologies Pvt. Ltd.
New no.2, Old no.10, 4th street
Venkateswara nagar, Adyar
CHENNAI – 600025
4. Scientech Technologies Pvt. Ltd.
202/19, 4th main street
Ganganagar,
BANGALORE- 560032
5. Scientech Technologies Pvt. Ltd.
8,1st floor, 123-Hariram Mansion,
Dada Saheb Phalke road,
Dadar (East), MUMBAI –400014
6. Scientech Technologies Pvt. Ltd.
988, Sadashiv Peth,
Gyan Prabodhini Lane,
PUNE – 411030
7. Scientech Technologies Pvt. Ltd
SPS Apartment, 1st Floor
2, Ahmed Mamoji Street,
Behind Jaiswal Hospital,
Liluah, HOWRAH-711204 W.B.
8. Scientech Technologies Pvt. Ltd
Flat No. 205, 2nd Floor,
Lakshminarayana Apartments
‘C’ wing, Street No. 17,
Himaytnagar,
HYDERABAD- 500029
Scientech Technologies Pvt. Ltd.
Ph: (0731) 5202959
Email: info@scientech.bz
Ph.: (011) 26513912, 26864943
Fax: (011) 26864943.
Email: ndel@scientech.bz
Ph.: (044) 42187548, 42187549
Fax: (044) 42187549
Email: chennai@scientech.bz
Ph.: (080) 51285011
Fax: (080) 51285022
Email: bangalore@scientech.bz
Ph.: (022) 56299457
Fax: (022) 24168767
Email: stplmum@scientech.bz
Ph.: (020) 24461673
Fax: (020) 24482403
Email: pune@scientech.bz
Ph.: +913355266800
Email: kolkata@scientech.bz
Ph.: (040) 55465643
Email: hyd@scientech.bz
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LIST OF ACCESSORIES
1.
2mm Patch cord (red) ................................................................1 Nos.
2.
2mm Patch cord (black) .............................................................3 Nos.
3.
2mm Patch cord (blue) ...............................................................5 Nos.
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NOTES
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NOTES
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