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Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
ELECTRONICS-I
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EXPERIMENT NO – 05
TO CONSTRUCT A FULL-WAVE CENTER-TAP RECTIFIER CIRCUIT & TO CHECK AND MEASURE THE INPUT & OUTPUTS WAVE FORMS ON OSCILLOSCOPE
THEORY: More useful and effective way of converting AC to DC is using both positive and negative range of
AC input signal. There are 2 kinds of circuit to use to do this. Figure-1 shows a circuit among the two.
Because this method uses all of input wave type as DC output, it is known as full-wave rectification.
Center-tap rectifier in Figure-1 uses secondary winding having center-tap. When the polarity of
voltage is the same as figure, anode has a positive polarity toward cathode. So D1 becomes a forward
bias and conduction status. On the contrary, D2 becomes a backward bias and non-conduction status.
Therefore only D1 supplies the current to load.
Figure-1 Because the polarity of secondary voltage of transformer is inverted in the next half cycle of AC, so
everything is in opposition to above condition. Therefore, D1 becomes backward bias and D2 becomes
forward bias, then D2 supplies current to load. Because each diode is insulation status during only the
half cycle (by half cycle in turn), load current which is double the current of half-wave rectifying.
Figure -2 shows its output wave type. Note that double the increase of frequency appears in output
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substantially. It is because cycle of output wave type T is the half of AC input signal. Remember that
frequency is the reciprocal of cycle. ( f T=1/ ).
Center tap circuit has been the most general full-wave rectifying circuit but, bridge circuit becomes
most general owing to the appearance of silicon diode having low price, high reliability and small size.
Figure- 3: I/O waveforms of full wave rectifier
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The reason is in the fact that it enables to cut down the size of transformer needed in getting the degree
of output as well as center tap. Current flows in turn by dividing secondary side of transformer half and
half during each half cycle of main-sub in center tap circuit.
During this one cycle of the input sine wave, two positive DC pulses have been developed.
With this Condition, the output frequency has doubled. If the input frequency is 50 hertz, the positive
alternation will be present 50 times. After the full-wave rectification, there will be 100 positive pulses
at the output. If the DC output signal is measured with a multi-meter, the indication will be the
average value of the peak signal.
To determine the average value of a full-wave rectified signal, multiply the peak value by 0.636 Example:
VAVG = VP * 0.636
Input peak value = 10 V AC
10 V AC x 0.636 = 6.36 V DC
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APPARATUS:
1. Low-voltage AC power supply 2. Two 1N4001 diode 3. Resistance 1KΩ 4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
SCHEMATIC DIAGRAM
PROCEDURE:
1. Connect the diodes to the low-voltage AC power supply as shown in a figure.
2. Connect CH1 of Oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
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INPUT WAVEFORM 5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
6. With the oscilloscope DC. Coupled adjust the time-base and the Y amplifier sensitivity. 7. Sketch the output waveform and label it to show the periods when the diode D1 is conducting
and when the diode D2 is conducting those. Time T depends upon the frequency of your power supply.
OUTPUT WAVEFORM
8. Measure and record time T and peak voltage Vp of an output supply.
T= _______________ Vp: _______________
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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EXPERIMENT NO – 06
INTRODUCTION OF PROTEUS SOFTWARE
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EXPERIMENT NO – 07
TO CONSTRUCT A FULL-WAVE BRIDGE RECTIFIER CIRCUIT AND TO CHECK AND MEASURE THE INPUT AND OUTPUTS WAVE FORMS ON OSCILLOSCOPE THEORY: A basic full-wave bridge rectifier is illustrated in Figure 1.
Figure 1 Basic Full-Wave Bridge Rectifier
A full wave bridge rectifier has one advantage over the conventional full-wave rectifier: the amplitude
of the output signal. The frequency of the positive pulses will be the same in either rectifier. When the
output signal is taken from a bridge rectifier, it is taken across the entire potential of the transformer;
thus, the output signal will be twice the amplitude of a conventional full-wave rectifier. For the first
half cycle of a bridge rectifier, refer to Figure 2.
Figure 2 Full Wave Bridge Rectifier (First Half-Wave Cycle Operation)
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During the first half cycle of the input signal, a positive potential is felt at Point A and a negative
potential is felt at Point B. Under this condition, a positive potential is felt on the anode of D2 and on
the cathode of D1. D2 will be forward-biased, while D1 will be reverse-biased. Also, a negative
potential will be placed on the cathode of D3 and the anode of D4. D3 will be forward-biased, while D4
will be reverse biased. With D3 and D2 forward-biased, a path for current flow has been developed.
The current will flow from the lower side of the transformer to Point D. D3 is forward-biased, so
current will flow through D3 to Point E, from Point E to the bottom of the load resistor, and up to Point
F. R3 is forward biased, so current will flow through D2, to Point C, and to Point A. The difference of
potential across the secondary of the transformer causes the current to flow. Diodes D3 and D2 are
forward-biased, so very little resistance is offered to the current flow by these components. Also, the
resistance of the transformer is very small, so approximately all the applied potential will be developed
across the load resistor. If the potential from Point A to Point B of the transformer is 24 volts, the
output developed across the load resistor will be a positive pulse approximately 24 volts in amplitude.
Figure 3. Full-Wave Bridge Rectifier (Second Cycle Operation) When the next alternation of the input is felt (Figure 3), the potential across the transformer reverses
polarity. Now, a negative potential is felt at Point A and a positive potential is felt at Point B. With a
negative felt at Point C, D1 will have a negative on the cathode and D2 will have a negative on the
anode. A positive at Point D will be felt on the anode of D4 and the cathode of D3. D1 and D4 will be
forward-biased and will create a path for current flow. D3 and D2 will be reverse-biased, so no current
will flow. The path for current flow is from Point A to
Point C, through D1 to Point E, to the lower side of the load resistor, through the load resistor to Point
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F, through D4 to Point D, and to the lower side of T1. Current flows because of the full potential being
present across the entire transformer; therefore, the current through the load resistor will develop the
complete voltage potential. The frequency of the output pulses will be twice that of the input pulses
because both cycles of the input AC voltage are being used to produce an output.
APPARATUS:
1. Low-voltage AC power supply
2. Four 1N4001 diode
3. Resistance 1KΩ
4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes
are suitable for the task, and they are quite easy to obtain.
SCHEMATIC DIAGRAM
Figure
PROCEDURE:
1. Connect the diodes to the low-voltage AC power supply as shown in a figure.
2. Connect CH1 of Oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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EXPERIMENT NO – 08
TO CHECK THE EFFECTS OF FILTER CAPACITANCE ON DC OUTPUT VOLTAGE AND RIPPLE ON OSCILLOSCOPE
THEORY:
The Capacitor Filter
The simple capacitor filter is the most basic type of power supply filter. The use of this filter is very
limited. It is sometimes used on extremely high-voltage, low-current power supplies that require very
little load current from the supply. This filter is also used in circuits where the power-supply ripple
frequency is not critical and can be relatively high.
The simple capacitor filter shown in figure 1 consists of a single-filter element. This capacitor (C) is
connected across the output of the rectifier bridge in parallel with the load. The RC charge time of the
filter capacitor (C) must be short and the RC discharge time must be long to eliminate ripple action
when using this filter. In other words, the capacitor must charge up fast with preferably no discharge at
all. Better filtering also results when the frequency is high; therefore, the full-wave rectifier output is
easier to filter than the half-wave rectifier because of its higher frequency.
Figure 1. - Full-wave rectifier with a capacitor filter
The value of the capacitor is fairly large (several microfarads).
When the pulsating voltage is first applied to the circuit, the capacitor charges rapidly and almost
reaches the peak value of the rectified voltage within the first few cycles. The capacitor attempts to
charge to the peak value of the rectified voltage anytime a diode is conducting, and tends to retain its
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charge when the rectifier output falls to zero. (The capacitor cannot discharge immediately). The
capacitor slowly discharges through the load resistance (RL) during the time the rectifier is not
conducting.
The rate of discharge of the capacitor is determined by the value of capacitance and the value of the
load resistance. If the capacitance and load resistance values are large, the RC discharge time for the
circuit is relatively long.
When the circuit is energized, the diode conducts on the positive half cycle and current flows through
the circuit allowing C to charge. C will charge to approximately the peak value of the input voltage.
The charge is less than the peak value because of the voltage drop across diodes.
If fewer ripples are desired under heavy-load conditions, a larger capacitor may be used.
APPARATUS:
1. Low-voltage AC power supply
2. Four 1N4001 diode
3. Capacitor
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
A larger capacitor value is fine to use in this experiment, so long as its working voltage is high enough. To be safe, choose a capacitor with a working voltage rating at least twice the RMS AC voltage output of the low-voltage AC power supply
SCHEMATIC DIAGRAM
INSTRUCTIONS:
1. Construct the bridge rectifier circuit by using rectifying diodes and RC smoothing circuit and
connect it to the low-voltage AC power supply as shown in a figure.
2. Connect CH1 of Oscilloscope to Input and CH2 to Output of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. With the oscilloscope DC. Coupled adjust the time-base and the Y amplifier sensitivity.
6. Check the output waveform when filtering capacitance is not connected and Sketch it.
7. Now connect filtering capacitance on Output side and check the output on oscilloscope and
sketch it.
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8. By changing RC change the Load and checks the effect on output waveform also sketches the
2. Find the Values of VL, VR, IZ, IL and IR when RL=1K ohm.
3. Change RL to 3.3K ohm; find the same values as step 2.
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EXPERIMENT NO – 11
SERIES CLIPPERS
Part-A: Series Un-Biased Clipper.
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistors(100-ohm, 1k-ohm)
4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure-1
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
6. With the oscilloscope DC. Coupled adjust the time-base and the Y amplifier sensitivity.
7. Sketch the output waveform.
OUTPUT WAVEFORM
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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Part-B: Series Biased Clipper.
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistors(100-ohm, 1k-ohm)
4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure-2
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
Construct the circuit in Figure-1 & Figure-2 by the use of Proteus Software also Submit a
printout of a proper labeled schematic. Include hand calculation.
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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ASSIGNMENT
Construct the circuit in Figure-1, 2, 3 &4 by the use of Proteus Software also Submit a printout of
a proper labeled schematic. Include hand calculation.
Figure-1
Figure-2
Figure-3
Figure-4
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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EXPERIMENT NO – 12
Parallel Clippers
Part-A: Parallel Un-Biased Clipper.
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistors(100-ohm, 1k-ohm)
4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure-1
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
6. With the oscilloscope DC. Coupled adjust the time-base and the Y amplifier sensitivity.
7. Sketch the output waveform.
OUTPUT WAVEFORM
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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Part-B: Parallel Biased Clipper.
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistors(100-ohm, 1k-ohm)
4. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure-2
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
Construct the circuit in Figure by the use of Proteus Software also Submit a printout of a
proper labeled schematic. Include hand calculation.
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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EXPERIMENT NO – 14
Unbiased Clamper
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistor 1k-ohm
4. Capacitor
5. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
Federal Urdu University of Arts, Science & Technology Islamabad – Pakistan Electrical Engineering
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply
Construct the circuit in Figure by the use of Proteus Software also Submit a printout of a
proper labeled schematic. Include hand calculation.
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EXPERIMENT NO – 15
Biased Clamper
APPARATUS:
1. Low-voltage AC power supply
2. One 1N4001 diode
3. Resistor 1k-ohm
4. Capacitor
5. Oscilloscope
The diodes need not be exact model 1N4001 units. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.
Circuit Diagram
Figure
PROCEDURE:
1. Connect the diode to the low-voltage AC power supply as shown in a figure. Note that the
resistor uses to limit the current.
2. Connect CH1 of oscilloscope to Input and CH2 to Output/Load Resistance of a circuit.
3. Switch on the oscilloscope and the sinusoidal supply.
4. Sketch the input waveform
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INPUT WAVEFORM
5. Measure and record time T , peak voltage Vp and peak to peak voltage Vpp of Input supply