AB33
Transistor Shunt
Voltage Regulator
Analog Lab
Experiment Board
Ver. 1.0
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An ISO 9001: 2000 company
94-101, Electronic Complex, Pardesipura INDORE-452010, India.
AB33
Tel.: 91-731-2570301 Fax: 91-731-2555643
Email: info@scientech.bz Web: www.scientech.bz
Scientech Technologies Pvt. Ltd.
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Scientech Technologies Pvt. Ltd.
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AB33
Transistor Shunt Voltage Regulator
AB33
Table of Contents
1.Introduction
4
2. Theory
6
3.Experiment 1
10
To study transistor shunt voltage regulator, when
input voltage Vin is fixed while Load resistance RL
is variable.
4.Experiment 2
13
To study transistor shunt voltage regulator, when
input voltage Vin is variable while Load resistance RL
is fixed.
5.Datasheet
15
6.Warranty
16
7.List of Service Centers
17
8.List of Accessories
18
9. Notes
19
Scientech Technologies Pvt. Ltd.
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AB33
Introduction
AB33 is a compact, ready to use Transistor Shunt Voltage Regulator
experiment board. This is useful for students to study the operation of
Transistor as a voltage regulator when it is connected in shunt or parallel
with load. 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, and potentiometer.
List of Boards :
Model
Name
AB01
AB02
AB03
AB04
AB05
AB06
AB07
AB08
AB09
AB10
AB11
AB12
AB13
AB14
AB15
AB16
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 Emitter Amplifier
Common Collector Amplifier
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
AB28
AB29
AB30
AB31
Scientech Technologies Pvt. Ltd.
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AB33
AB32
AB33
AB35
AB39
AB41
AB42
AB43
AB44
AB45
AB49
AB51
AB52
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
Transistor Series Voltage Regulator
Transistor Shunt Voltage Regulator
DC Ammeter
Instrumentation Amplifier
Differential Amplifier (Transistorized)
Operational Amplifier (Inverting / Non-inverting /
Differentiator)
Operational Amplifier (Adder/Scalar)
Operational Amplifier (Integrator/ Differentiator)
Schmitt Trigger and Comparator
K Derived Filter
Active filters (Low Pass and High Pass)
Active Band Pass 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
………… and many more
Scientech Technologies Pvt. Ltd.
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Theory
Circuits that maintain power supply voltages or current output within
specified limits, or tolerances are called Regulators. They are designated as
dc voltage or dc current regulators, depending on their specific application.
Voltage regulator circuits are additions to basic power supply circuits,
which are made up of rectifier and filter sections (Fig. 1). The purpose of
the voltage regulator is to provide an output voltage with little or no
variation. Regulator circuits sense changes in output voltages and
compensate for the changes.
Fig. 1
There are two types of voltage regulators. Basic voltage regulators are
classified as either Series or Shunt, depending on the location or position of
the regulating element (s) in relation to the circuit load resistance. Fig 2
illustrates these two basic types of voltage regulators. Broken lines have
been used in the figure to highlight the difference between the series and
shunt regulators.
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Fig 2
The schematic drawing in view A is that of a shunt regulator. It is called
shunt regulator because the regulating device is connected in shunt or in
parallel with the load resistance. Fig 2 illustrates the principle of shunt
voltage regulation. From the figure it is clear that the regulator is in shunt
with the load resistance (RL). In a shunt voltage regulator, as shown in Fig
2, Output voltage regulation is determined by parallel resistance of the
regulating device, the Load resistance (RL), and the series resistor Rs. If the
load resistance RL increases/decreases, the regulating device
decreases/increases its resistance to compensate for the change.
The schematic for a typical series voltage regulator is shown in Figure 3. It
employs the NPN transistor in shunt configuration in place of the variable
resistor found in Fig 2.
Since AB is in parallel across VL, we have
VL −VZ −VBE = 0 or VBE = VL −VZ (kirchoff's Voltage Law)
Also VL = VZ + VBE
i.e. The output voltage is close to the sum of the voltage across Zener and
the voltage at the base-emitter junction of transistor.
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Fig. 3
Note : Regulated output voltage might be slightly higher than the expected
voltage due to tolerance of Zener diode.
Circuit Operation :
Case 1: when input voltage is constant while Load varies.
Since VZ is fixed, any decrease or increase in VL will have a corresponding
effect on VBE. Suppose, VL decreases, then as seen from the above relation
VBE also decreases. As a result, IB decreases, hence IC ( = βIB) decreases,
thereby decreasing I and hence VR (=IR). Consequently, VL increases
because at all times
Vin = VR + VL or VL = Vin - VR
From the above description it is concluded that when by any reason VL
decreases VR also decreases thereby keeping VL constant.
Similarly, when by any reason VL increases VR also increases thereby
keeping VL constant.
Case 2 : when input voltage varies while Load remains constant.
When the input voltage increases, output voltage across increases
momentarily. This momentarily deviation or variation, from the required
regulated output voltage of 6.3 volts is a result of a rise in the input voltage.
This increases forward bias of transistor. Recall that the voltage drop across
Zener remains constant at 5.6V. Since the output voltage is composed of the
Zener voltage and the base-emitter voltage, the output voltage momentarily
increases. At this time, the increase in the forward bias of transistor lowers
the resistance of the transistor allowing more current to flow through it.
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Since this current must also pass through R, there is also an increase in the
voltage drop across this resistor. Due to increase in this voltage drop across
R, voltage across VL remains close to the required regulated value of output
voltage.
Similarly, when input voltage decreases, forward bias of transistor also
decreases. This decrease in bias voltage increases the resistance of transistor
allowing less current to flow through it. Since this current must pass
through resistor R, there is also an decrease in the voltage drop across this
resistor. This drop in voltage across R maintain output voltage close to the
required regulated value.
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Experiment 1
Objective :
To study Transistor shunt voltage regulator, when input voltage V in is
fixed while Load resistance RL is variable.
Apparatus required :
1.
Analog board of AB33.
2.
DC power supply +12V external source or ST2612 Analog Lab.
3.
Digital Multimeter (2 numbers).
4.
2 mm patch cords.
Circuit diagram :
Circuit used to study Transistor shunt voltage regulator is shown in Fig 4.
Fig. 4
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Procedure :
•
Connect + 12V dc power supply at its indicated position from
external source or ST2612 Analog Lab.
1.
Connect one voltmeter between test point 1 and ground to measure
input voltage Vin.
2.
Connect ohmmeter between test point 5 and ground and set the value
of load resistance RL at some fixed value [full load (1.1K), 1K,
500Ω...]
3.
Connect a 2mm patch cord between test point 3 and 4.
4.
Connect voltmeter between test point 5 and ground to measure
output voltage Vout.
5.
Switch ON the power supply.
6.
Vary the potentiometer P1 to set fixed value of input voltage Vin =
9V and measure the corresponding values of
a.
Output voltage Vout between test points 5 and ground.
b.
Zener voltage VZ between test points 2 and 6.
c.
Forward bias voltage VBE of transistor between test point 6
and ground.
7.
Disconnect the 2mm patch cord between test point 3 and 4.
8.
Repeat the procedure from step 3 for different sets of load resistance
RL and note the results in an observation Table 1.
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Observation Table 1 :
Sr.
No.
Load
Resistance
RL
1.
2.
3.
4.
5.
6.
7.
Full Load (1.1K)
1K Ω
800 Ω
600 Ω
400 Ω
200 Ω
No Load
Voltage
Across
Zener
VZ
Forward
bias
voltage
VBE
Output voltage
Vout at constant
Input voltage
Vin = 9 volt
Note : To measure Voltage at No Load disconnect 2mm patch cord between
test point 3 and 4, measure voltage between test point 3 and ground.
Calculations :
Percentage regulation is given by formula
% Regulation = [(VNL − VFL) / VFL] * 100
VNL = no-load or open-circuit terminal voltage.
VFL = full-load terminal voltage.
Results :
1.
The result of Experiment 1 reveal that for the network of Fig 3 with a
fixed input voltage Vin the output voltage will remain close to 6.3 V
for a range of load resistance that extends from ______ to _______ .
2.
Percentage regulation = _______%.
Scientech Technologies Pvt. Ltd.
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Experiment 2
Objective :
To study Transistor shunt voltage regulator, when input voltage V in is
variable while Load resistance RL is fixed.
Apparatus required:
1.
Analog board of AB33.
2.
DC power suppy +12V external source or ST2612 Analog Lab.
3.
Digital Multimeter (2 numbers).
4.
2 mm patch cords.
Circuit diagram :
Circuit used to study Transistor shunt voltage regulator is shown in Fig 5.
Fig. 5
Scientech Technologies Pvt. Ltd.
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Procedure :
•
Connect +12V dc power supplies at their indicated position from
external source or ST2612 Analog Lab.
1.
Connect one voltmeter between test point 1 and ground to measure
input voltage Vin
2.
Connect ohmmeter between test point 5 and ground and set the value
of load resistance RL at maximum value.
3.
Connect a 2mm patch cord between test point 3 and 4.
4.
Connect voltmeter between test point 5 and ground to measure
output voltage Vout.
5.
Switch ON the power supply.
6.
Vary the potentiometer P1 to set fixed value of input voltage Vin =
7V, 8V, 9V and measure the corresponding values of
a.
Output voltage Vout between test points
5 and ground.
b.
Zener voltage VZ between test points 2
and 6.
c.
Forward bias voltage VBE of transistor
between test point 6 and ground.
7.
Repeat the procedure from step 7 for different sets of input voltage
Vin and note the results in an observation Table 2.
Observation Table 2 :
Sr.
No.
Input
Voltage
Vin
1.
2.
3.
4.
5.
7V
8V
9V
10 V
11 V
Voltage
Across
Zener VZ
Forward
bias
voltage VBE
Output voltage
Vout at fixed load
resistance RL = Max
Results :
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1.
The result of Experiment 2 reveal that for the network of Fig 5 with a
fixed Load resistance, the output voltage will remain close to 6.3V
for a range of input voltage Vin that extends from _____ to_____ .
Scientech Technologies Pvt. Ltd.
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Datasheet
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.
DESPATCH 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.
Scientech Technologies Pvt. Ltd.
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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, C-19,
F.I.E., Patparganj Industrial Area,
DELHI – 110092
3. Scientech Technologies Pvt. Ltd.
1st floor No 1 Karpagam Gardens
Main Road Adyar
CHENNAI – 600020
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) 2570301
Email : info@scientech.bz
Ph : (011) 22157370, 22157371
Fax : (011) 22157369
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) ......................................................1 Nos.
3.
2mm Patch cord (blue) ........................................................1 Nos.
Scientech Technologies Pvt. Ltd.
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Notes
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Notes
Scientech Technologies Pvt. Ltd.
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