EC Lab Manual

29
Dept. of CSE Electronic Circuits Lab Manual Bangalore Institute of Technology, Bangalore 1 1a. CLIPPING AND CLAMPING CIRCUITS AIM: To study the working of positive clipper, double ended clipper and positive clamper using diodes. COMPONENTS REQUIRED: Diode (IN914 / IN4007), Resistors-1 K & 100k, DC regulated power supply (for Vref), Signal generator (for Vi) and CRO. CIRCUIT DIAGRAM OF POSITIVE CLIPPER Fig.1 a Positive clipper Circuit b. Transfer Characteristics Clippers clip off a portion of the input signal without distorting the remaining part of the waveform. In the positive clipper shown above the input waveform above Vref is clipped off. If Vref = 0V, the entire positive half of the input waveform is clipped off. Plot of input Vi (along X-axis) versus output Vo (along Y-axis) called transfer characteristics of the circuit can also be used to study the working of the clippers. For stiff clipper: 100R B < R S < 0.01R L , Where R B is bulk resistance of the diode. For diode IN914, value of R B is 30.Series resistor R S must be 100times greater than bulk resistance R B and 100 times smaller than load resistance R L . If R B =30, select R S =1k and R L =100k. PROCEDURE: 1. Before making the connections check all components using multimeter. 2. Make the connections as shown in circuit diagram. 3. Using a signal generator (V i ) apply a sine wave of 1KHz frequency and a peak-to- peak amplitude of 10V to the circuit. (Square wave can also be applied.) 4. Keep the CRO in dual mode, connect the input (Vi) signal to channel 1 and output waveform (Vo) to channel 2. Observe the clipped output waveform which is as shown in fig. 2. Also record the amplitude and time data from the waveforms. 5. Now keep the CRO in X-Y mode and observe the transfer characteristic waveform.

Transcript of EC Lab Manual

Page 1: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 1

1a. CLIPPING AND CLAMPING CIRCUITS

AIM: To study the working of positive clipper, double ended clipper and positive clamper

using diodes.

COMPONENTS REQUIRED: Diode (IN914 / IN4007), Resistors-1 K & 100k, DC

regulated power supply (for Vref), Signal generator (for Vi) and CRO.

CIRCUIT DIAGRAM OF POSITIVE CLIPPER

Fig.1 a Positive clipper Circuit b. Transfer Characteristics

Clippers clip off a portion of the input signal without distorting the remaining part of

the waveform. In the positive clipper shown above the input waveform above Vref is clipped

off. If Vref = 0V, the entire positive half of the input waveform is clipped off.

Plot of input Vi (along X-axis) versus output Vo (along Y-axis) called transfer

characteristics of the circuit can also be used to study the working of the clippers.

For stiff clipper: 100RB < RS< 0.01RL, Where RB is bulk resistance of the diode. For

diode IN914, value of RB is 30.Series resistor RS must be 100times greater than bulk

resistance RB and 100 times smaller than load resistance RL.

If RB=30, select RS=1k and RL=100k.

PROCEDURE:

1. Before making the connections check all components using multimeter.

2. Make the connections as shown in circuit diagram.

3. Using a signal generator (Vi) apply a sine wave of 1KHz frequency and a peak-to-

peak amplitude of 10V to the circuit. (Square wave can also be applied.)

4. Keep the CRO in dual mode, connect the input (Vi) signal to channel 1 and output

waveform (Vo) to channel 2. Observe the clipped output waveform which is as shown

in fig. 2. Also record the amplitude and time data from the waveforms.

5. Now keep the CRO in X-Y mode and observe the transfer characteristic waveform.

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Dept. of CSE Electronic Circuits Lab Manual

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Note:

1. Vary Vref and observe the variation in clipping level. For this use variable DC power

supply for Vref.

2. Change the direction of diode and Vref to realize a negative clipper.

3. For double-ended clipping circuit, make the circuit connections as shown in fig.3 and

the output waveform observed is as shown in figure 5.

4. Adjust the ground level of the CRO on both channels properly and view the ouput in

DC mode (not in AC mode) for both clippers and clampers.

WAVEFORMS

Fig. 2. Input and output waveform for positive Clipper

RESULT: Output voltage V0 =__________ during positive half cycle =__________ during negative half cycle

DOUBLE ENDED CLIPPER

Fig.3 Double ended clipper Circuit b. Transfer Characteristics

Apply Vi = 10 Vpp at 1kHz V1= 2V

V2= -2V

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WAVE FORMS

Fig. 4. Input and output waveform for double-ended clipping circuit

RESULT: Output voltage V0 =__________ during positive half cycle

=__________ during negative half cycle

Note: The above clipper circuits are realized using the diodes in parallel with the load (at the

output), hence they are called shunt clippers. The positive (and negative) clippers can also be

realized in the series configuration wherein the diode is in series with the load. These circuits

are called series clippers.

POSITIVE CLAMPER

COMPONENTS REQUIRED: Diode (IN 914/BY-127), Resistor of 100 K, Capacitor - 1

F, DC regulated power supply, Signal generator, CRO

Fig. 5 Positive Clamper

The clamping network is one that will “clamp” a signal to a different DC level. The

network must have a capacitor, a diode and a resistive element, but it can also employ an

independent DC supply (Vref) to introduce an additional shift. The magnitude of R and C

must be chosen such that time constant τ = RLC is large enough to ensure the voltage across

capacitor does not discharge significantly during the interval of the diode is non-conducting.

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Dept. of CSE Electronic Circuits Lab Manual

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DESIGN:

For proper clamping, τ >100T where T is the time period of input waveform

If frequency is 1 kHz with peak-peak input voltage of 10V, T=1ms

τ = RL.C=100×T = 100ms

Let C=1μF

RL= 100×10-3 =100kΩ

1×10-6

Select C =1uF and RL =100 kΩPROCEDURE:

1. Before making the connections check all components using multimeter.

2. Make the connections as shown in circuit diagram (fig. 5).

3. Using a signal generator apply a square wave input (Vi) of peak-to-peak amplitude of

10V (and frequency greater than 50Hz) to the circuit. (Sine wave can also be applied)

4. Observe the clamped output waveform on CRO which is as shown in Fig. 6.

Note: 1.For clamping circuit with reference voltage Vref, the output waveform is observed as

shown in Fig. 7. For without reference voltage, Keep Vref = 0V.

2. CRO in DUAL mode and DC mode. Also the grounds of both the channels can be

made to have the same level so that the shift in DC level of the output can be observed.

3. For negative clampers reverse the directions of both diode and reference voltage.

Fig. 6 Input and output waveform for positive clamper without reference voltage.

Fig. 7 Input and output waveform for positive clamper circuit with reference voltage = 2V

RESULT:

With Vref =0, output voltage V0=_________With Vref =2, output voltage V0=_________

Page 5: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

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2a. CE AMPLIFIER

AIM: To determine the frequency response, input impedance, output impedance and

bandwidth of a CE amplifier.

COMPONENTS REQUIRED: Transistor SL-100, Resistors -33 K, 6.8 K, 470,

2.2k, 10k Capacitors - 47 F, 10 F, DC regulated power supply, Signal generator, CRO

PROCEDURE:

1. Before making the connections check all components using multimeter.

2. Make the connections as shown in circuit diagram.

3. Using a signal generator apply a sinusoidal input waveform of peak-to-peak

amplitude 5mV (Vin) to the circuit and observe the output signal on the CRO.

4. Vary the frequency of input from 50Hz to 1MHz range and note down corresponding

output voltage VO in the tabular column.

Note: When the input frequency is being changed the input amplitude (i.e., around 20

mV) should remain constant.

Adjust the amplitude of Vin (in mV) such that the output Vo does not get clipped (i.e.,

saturated) when the frequency is in the mid range say 1kHz.

5. After the frequency has been changed from 50 Hz to 1MHz and the readings are

tabulated in a tabular column, calculate gain of the amplifier (in dB) using the

formula,

Gain in dB = 20 log 10 (Vo/Vin)

6. Plot the graph of gain versus frequency on a semi log sheet and hence determine the

bandwidth as shown in Fig. 3. Bandwidth = B = f2-f1

To find input impedance, set the input DRBI to a minimum value and DRBO to a

maximum value (say, 10k) as shown in figure 2. Now apply an input signal using signal

generator, say a sine wave whose peak-to-peak amplitude is 5mV with a frequency of 10

KHz. Observe the output on CRO. Note this value of output with DRBI = 0 as V0max.

Now increase the input DRBI value till the output voltage V0 = (1/2) V0max. The

corresponding DRBI value gives input impedance.

To find output impedance, set DRBO which is connected across the output to a

maximum value as shown in figure 2, with the corresponding DRBI at the minimum

position. Apply the input signal using signal generator, say a sine wave whose peak-to-

peak amplitude is 50mV with a frequency of 10 KHz. Observe the output on CRO. Note

this value of output with DRBI = 0 as V0max. Now decrease the DRBO value till the

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Dept. of CSE Electronic Circuits Lab Manual

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output voltage V0 = (1/2) V0max. The corresponding DRBO value gives output

impedance.

Note: DRBI is connected between the signal generator and the input coupling capacitor.

DRBO is connected across the output (across the CRO terminals).

The ground symbol in the circuit diagram implies a common point. In some of the power

supplies, there will be three terminals - + (plus), - (minus) and GND (ground). Never

connect this GND terminal to the circuit.

TABULAR COLUMN

Vi = 5 mV (P-P)

fin Hz

V0 P-P

volts AV =iV

V0Power Gain = 20 log10 Av

in dB

50 Hz----

1 MHz

Fig. 1 : Transistor as a CE amplifier circuit diagram

ValuesR1 = 33kΩR2 = 6.8kΩRC = 2.2kΩRE = 470ΩRL = 10kΩCC1 = CC2 =10μFCE=47μF

Page 7: EC Lab Manual

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Fig. 2: CE Amplifier with DRBs connected at both input and output

WAVEFORMS:

FREQUENCY RESPONSE:

Fig. 3 Frequency response plotted on semilog graph (X-axis is log scale)

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RESULT:1. BANDWIDTH = Hz2. INPUT IMPEDANCE = Ω3. OUTPUT IMPEDANCE = Ω

Note: Maximum gain occurs in mid frequency region. This is also called mid band gain.Gain-bandwidth product = Midband gain x BandwidthTHEORY:

The frequency response of an amplifier is the graph of its gain versus the frequency.

Fig. 3 shows the frequency response of an ac amplifier. In the middle range of frequencies,

the voltage gain is maximum. The amplifier is normally operated in this range of frequencies.

At low frequencies, the voltage gain decreases because the coupling (CC in Fig.1) and bypass

(CE) capacitors no longer act like short circuits; instead some of the ac signal voltage is

attenuated. The result is a decrease of voltage gain as we approach zero hertz. At high

frequencies, voltage gain decreases because the internal (parasitic) capacitances across the

transistor junctions provide bypass paths for ac signal. So as frequency increases, the

capacitive reactance becomes low enough to prevent normal transistor action. The result is a

loss of voltage gain.

Cutoff frequencies (f1 & f2 in Fig. 3) are the frequencies at which the voltage gain

equals 0.707 of its maximum value. It is also referred to as the half power frequencies

because the load power is half of its maximum value at these frequencies.

DESIGN:

Given: 10,50&2,10 SmAIVV CCC

Assume VRE=VCC/10, VCE= VCC/2.

Apply KVL to the output circuit of transistor.

VCC=ICRC+ VCE+ VRE

VRC= VCC- VRE - VCE

=10-1-5 = 4v

RC= VRC /IC = 2000 Ω.

Select RC = 2.2kΩ.

To find RE, let VVRIV CCEERE 110

1 , and CE II

Hence 5002

1

maI

V

I

VR

C

RE

E

REE .

Choose RE = 470 Ω.

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Bangalore Institute of Technology, Bangalore 9

Voltage across resistor R2 is

VR2 = VCC R2 / R1+ R2 -------------------------------------------- 1

Stability factor S = 1+B/1+B(RE / RE + RB ) ------------------------ 2

Substitute all the values in the above equation and calculate RB.

RB = 5.6k Ω.

But RB = R1R2/R1+R2. ---------------------------------------------------3

From the circuit VR2 = VBE + VRE =0.7 V+1.0V = 1.7v

From Eq 1

1.7V = 10* R2/R1+R2. -------------------------------------------------- 4

From Eq 3

RB = 5.6kΩ = R1R2/R1+R2. ------------------------------------------- 5

Using Equation 4&5 calculate R1 and R2

R1= 33kΩ

R2 =6.8kΩ

To find the bypass capacitor CE: Let XCE = RE/10 at f = 75Hz

Hence102

1 E

ECE

R

fCX

Substituting all the values, CE =45 µF.

Choose CE =47 µF and the coupling capacitors CC1 = CC2 = 10 µF.

Input impedance (Zi ) = RB || βre`

Where re` = 25 mv/IE = 25 x 10-3 /2 x 10-3 = 22.7 Ω

Out impedance (Z0) of the CE amplifier is the thevenin’s impedance

Zo = RC || RL

Page 10: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 10

3a. CHARACTERISTICS OF AN ENHANCEMENT MODE MOSFET

AIM: To determine the drain characteristics and Tranconductance characteristics of an

enhancement mode MOSFET.

COMPONENTS REQUIRED: MOSFET (1RF 740), Resistor (1kΩ), Voltmeters (0-30V

range and 0-10V range), Ammeter (0- 25mA range) and Regulated power supply (2 nos. –

variable power supply)

CIRCUIT DIAGRAM:

Enhancement MOSFET

Characteristics

Fig. 2a. Drain Characteristics and b.Tranconductance characteristics

PROCEDURE:1. Make the connections as shown in the corresponding circuit diagram. Special care to

be taken in connecting the voltmeters and ammeters according to the polarity shown

in circuit diagram.

2. Repeat the procedure for finding drain and Transconductance characteristics of

Enhancement MOSFET.

Page 11: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

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3. Tabulate the readings in separate tabular columns as shown below.

4. Plot the drain characteristics (ID versus VDS for different values of gate voltages VGS).

Take ID along the Y-axis and VDS along the X-axis in the plot.

5. From this plot of drain characteristics find the drain resistanceD

DSd I

Vr

.

6. Similarly plot the Tranconductance characteristics with ID along the Y-axis and VGS

along the X-axis in the graph for one value of VDS, say VDS = 5V.

7. From this plot find the mutual conductance or transconductanceGS

Dm V

Ig

8. Lastly find the amplification factor, md gr

Procedure for finding the Tran conductance Characteristics:

1. Switch on the power supplies, with both V2 and V1 at zero voltage.

2. Initially set V1 =VGS = 0V. Now set V2 = VDS = 5V (constant). Vary the power

supply V1 i.e., VGS and note down the corresponding current ID (in mA)

(Simultaneously note down the VGS value from the voltmeter connected at the gate

terminal).

3. Repeat the above procedure for a different value of VDS, say 10V.

Note: In the above procedure VDS (i.e., the power supply V2) is kept constant and the power

supply V1 (=VGS) is varied.

Drain Characteristics:

1. Initially set V1 = VGS =4V (constant), slowly vary V2 and note down the

corresponding current ID. Simultaneously note down in the tabular column the

voltmeter reading VGS.

2. Repeat the above procedure for different values of VGS and note down the current

ID for corresponding V1 = VDS.

3. Plot the graph of ID versus VDS for different values of gate voltages.

Note: In the above procedure VDS (i.e., the power supply V2) is varied and the power supply

V1 (=VGS) is kept constant.

Page 12: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 12

READINGS TABULATED IN TABULAR COLUMN

Drain Characteristics

VGS=+2V VGS=+4V VGS=+6VVDS

(V)ID

maVDS

(V)ID

maVDS

(V)ID

ma

02....

10

02....

10

02....

10

Transconductance Characteristics

VDS = 5 V VDS = 10 VVGS

VoltsID

maVGS

VoltsID

ma0.....

10

0.....

10

Page 13: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 13

4 a. SCHMITT TRIGGERAIM: To design and implement a Schmitt trigger circuit using op-amp for the given UTP and

LTP values.

COMPONENTS REQUIRED: IC μA 741, Resistor of 10KΩ, 100KΩ, DC regulated power

supply, Signal generator, CRO

DESIGN: From theory of Schmitt trigger circuit using op-amp, we have the trip points,

kkandRR

selectRR

RRR

RR

vRv

RRVRUTP

vfVDesign

VR

RRLTPUTPV

kKRKR

RRV

RR

VRLTPUTP

RR

VRLTPUTP

VRR

RR

VR

RR

VRLTP

VVRR

VR

RR

VRUTP

sat

sat

ref

sat

sat

ref

ref

satref

ccsatrefsat

3322.81

142

1521

10*2

/1

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-(1)-----.22

used.isdesignfollowing the values,&, thefind to values UTP&LTPgiven theHence

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of90%opamp theofsaturationpositive theis where

21

1

21

21

21

12

21

1

21

21

21

1

21

2

21

2

21

1

PROCEDURE:

1. Before doing the connections, check all the components using multimeter.

2. Make the connection as shown in circuit diagram.

3. Using a signal generator apply the sinusoidal input waveform of peak-to-peak

amplitude of 10V, frequency 1 kHz.

4. Keep the CRO in dual mode; apply input (Vin) signal to the channel 1 and observe the

output (Vo) on channel 2 which is as shown in the waveform below. Note the

amplitude levels from the waveforms.

5. Now keep CRO in X-Y mode and observe the hysteresis curve.

Page 14: EC Lab Manual

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Circuit diagram

Circuit Diagram of Schmitt Trigger Circuit

Waveforms: Design1

CRO in DUAL mode

Hysteresis curve

CRO in X-Y mode showing the Hysteresis curve

Page 15: EC Lab Manual

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Waveforms: Design2:

Hysteresis curve

THEORY:Schmitt Trigger converts an irregular shaped waveform to a square wave or pulse.

Here, the input voltage triggers the output voltage every time it exceeds certain voltage levels

called the upper threshold voltage VUTP and lower threshold voltage VLTP. The input voltage

is applied to the inverting input. Because the feedback voltage is aiding the input voltage, the

feedback is positive. A comparator using positive feedback is usually called a Schmitt

Trigger. Schmitt Trigger is used as a squaring circuit, in digital circuitry, amplitude

comparator, etc.

Page 16: EC Lab Manual

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Bangalore Institute of Technology, Bangalore 16

5a. OP-AMP AS A RELAXATION OSCILLATOR

AIM: To design and implement a rectangular waveform generator (op-amp relaxation

oscillator) for a given frequency.

COMPONENTS REQUIRED: Op-amp μA 741, Resistor of 1KΩ, 10KΩ, 20 kΩ

Potentiometer, Capacitor of 0.1 μF, Regulated DC power supply, CRO

DESIGN:

The period of the output rectangular wave is given as

1

1ln2RCT -------(1)

Where,21

1

RR

R

is the feedback fraction

If R1 = R2, then from equation (1) we have T = 2RC ln(3)

Another example, if R2=1.16 R1, then T = 2RC ----------(2)

Design for a frequency of 1 kHz (implies msf

T 11010

11 33

)

Use R2=1.16 R1, for equation (2) to be applied.

Let R1 = 10kΩ, then R2 = 11.6kΩ (use 20kΩ potentiometer as shown in circuit figure)

Choose next a value of C and then calculate value of R from equation (2).

Let C=0.1µF (i.e., 10-7), then

KC

TR 5

102

10

2 7

3

. Select R=4.7KΩ

The voltage across the capacitor has a peak voltage of satc VRR

RV

21

1

PROCEDURE:

1. Before making the connections check all the components using multimeter.

2. Make the connections as shown in figure and switch on the power supply.

3. Observe the voltage waveform across the capacitor on CRO.

4. Also observe the output waveform on CRO. Measure its amplitude and frequency.

Page 17: EC Lab Manual

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Circuit Diagram & actual connections

WAVEFORMS

RESULT:The frequency of the oscillations = ___ Hz.

THEORY:

Op-Amp Relaxation Oscillator is a simple Square wave generator which is also called as a

Free running oscillator or Astable multivibrator or Relaxation oscillator. In this figure the

op-amp operates in the saturation region. Here, a fraction (R1/ (R1+R2)) of output is fed back

to the noninverting input terminal. Thus reference voltage is (R1/ (R1+R2)) Vo. And may

take values as + (R1/ (R1+R2)) Vsat or - (R1/ (R1+R2)) Vsat. The output is also fed back to

the inverting input terminal after integrating by means of a low-pass RC combination. Thus

whenever the voltage at inverting input terminal just exceeds reference voltage, switching

takes place resulting in a square wave output.

ValuesC=0.1μFR1 = 10kΩ, R2 = 11.6 kΩ,R = 4.7k/5.1kΩ

Page 18: EC Lab Manual

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6. ASTABLE MULTIVIBRATOR USING 555 TIMERSAIM: To design and implement an astable multivibrator using 555 Timer for a given

frequency and duty cycle.

COMPONENTS REQUIRED: 555 Timer IC, Resistors of 3.3KΩ, 6.8KΩ, Capacitors of

0.1 μF, 0.01 μF, Regulated power supply, CRO

DESIGN: Given frequency (f) = 1 KHz and duty cycle = 60% (=0.6)

The time period T =1/f = 1ms = tH + tL

Where tH is the time the output is high and tL is the time the output is low.

From the theory of astable multivibrator using 555 Timer (refer Malvino), we have

tH = 0.693 RB C ------(1)

tL = 0.693 (RA + RB)C ------(2)

T = tH + tL = 0.693 (RA +2 RB) C

Duty cycle = tH / T = 0.6. Hence tH = 0.6T = 0.6ms and tL = T – tH = 0.4ms.

Let C=0.1μF and substituting in the above equations,

RB = 5.8KΩ (from equation 1) and RA = 2.9KΩ (from equation 2 & RB values).

The Vcc determines the upper and lower threshold voltages (observed from the capacitor

voltage waveform) as CCLTCCUT VVVV3

1&

3

2 .

Note: The duty cycle determined by RA & RB can vary only between 50 & 100%. If RA is

much smaller than RB, the duty cycle approaches 50%.

Design 2: frequency = 1 kHz and duty cycle =75%, RA = 7.2kΩ & RB =3.6kΩ, choose RA =

6.8kΩ and RB = 3.3kΩ.

Circuit Diagram and actual connections

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PROCEDURE:1. Before making the connections, check the components using multimeter.

2. Make the connections as shown in figure and switch on the power supply.

3. Observe the capacitor voltage waveform at 6th pin of 555 timer on CRO.

4. Observe the output waveform at 3rd pin of 555 timer on CRO (shown below).

5. Note down the amplitude levels, time period and hence calculate duty cycle.

RESULT: tH =-------------

tL = ------------

T = -------------

The frequency of the oscillations = 1/T= ___ Hz.

%Duty cycle (DC) = tH/T*100 = ----------

WAVEFORMS

---------T ---------THEORY:

Multivibrator is a form of oscillator, which has a non-sinusoidal output. The output

waveform is rectangular. The multivibrators are classified as: Astable or free running

multivibrator: It alternates automatically between two states (low and high for a rectangular

output) and remains in each state for a time dependent upon the circuit constants. It is just an

oscillator as it requires no external pulse for its operation. Monostable or one shot

multivibrator: It has one stable state and one quasi stable. The application of an input pulse

triggers the circuit time constants. After a period of time determined by the time constant, the

circuit returns to its initial stable state. The process is repeated upon the application of each

trigger pulse. Bistable Multivibrators: It has both stable states. It requires the application of

an external triggering pulse to change the output from one state to other. After the output has

changed its state, it remains in that state until the application of next trigger pulse. Flip flop is

an example.

Page 20: EC Lab Manual

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SIMULATIONPOSITIVE CLIPPER

AIM: To build and simulate the positive clipper, double-ended clipper and positive clamper

circuits using a simulation package

Waveforms

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 5msec step size:0.01msec

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DOUBLE ENDED CLIPPER

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 5msec step size:0.01msec

Page 22: EC Lab Manual

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POSITIVE CLAMPER (without reference)

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 5msec step size:0.01msec

Page 23: EC Lab Manual

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POSITIVE CLAMPER WITH REFERENCE

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 5msec step size:0.01msec

Page 24: EC Lab Manual

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COMMON EMITTER AMPLIFIER

AIM: To build the CE amplifier circuit using a simulation package and determine the voltage

gain for two different values of supply voltage and for two different values of emitter

resistance.

Type of analysis: Ac Sweep Sweep type: logrithemic

Start frequency: 10 Hz End frequency: 100Meg points per decade: 40

Result: parametric Analysis (must be used in conjunction with Ac Sweep) to verify the change in output with variation in source Vcc or emitter resistance RE.

Step 1: To change the value of emitter resistance RE

a) Select the emitter resister and change the value to Rval b) Select PARAM from special libraryc) Double click on the parameter, write name 1 = Rval and initial value = 470 ohmsd) Click on analysis icon on the screen Select set up

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Select parametric analysis Select sweep variables as shown

Global parameter Name: Rval

Start value = 470 End value = 660 Increment = 200 Sweep type: linear Click ok

e) Check the variation in gain on the displayVoltage gain with VCC = 10V and emitter resistor RE = 470 ohms is _________Voltage gain with VCC = 10V and emitter resistor RE = 660 ohms is _________

Step 2: To change VCC from 10 V – 12 V in steps of 2 V along with ac sweepuse parametric analysis

a) Click on analysis icon on the screen Select set up Select parametric analysis

Select sweep variables as shown Sweep variable type: Voltage source Name: V1

Sweep type: linear Start value = 10 End value = 12 Increment = 2

Click okb) Check the variation in gain on the display

Voltage gain with VCC = 10V and emitter resistor RE = 470 ohms is _________Voltage gain with VCC = 12V and emitter resistor RE = 470 ohms is _________

Page 26: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 26

CMOS INVERTER

AIM: To implement a CMOS inverter using a simulation package and verify its truth table.

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 100usec step size:0.1usec

Skip the initial transients

Page 27: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 27

SCHMITT TRIGGER

AIM: To implement a Schmitt trigger using Op-Amp using a simulation package for two sets

of UTP and LTP values.

Type of analysis: TIME DOMAIN (TRANSIENT)

Run to time: 40msec step size: 0.1msec

On the display window select settings, click on X-axis and select axis variable.Type input voltage on X-axis. Next click on Trace icon, select Add trace and write outputvoltage on Y- axis. Observe Hystersis curve on the display and measure Hystersis voltage VH.

Repeat for two values of UTP and LTP

Page 28: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 28

RELAXSATION OSCILLATOR

AIM: To implement a rectangular waveform generator (Op-Amp relaxation oscillator) using

a simulation package and observe the change in frequency when all resistor values are

doubled.

TYPE OF ANALYSIS : TIME DOMAINRUN TO TIME : 4msMAXIMUM STEP SIZE: 0.01msResult: 1. the time/frequency of output waveform is ----------------- 2. Double all the resister values and measure the time/frequency of output Waveform -------------------.

Page 29: EC Lab Manual

Dept. of CSE Electronic Circuits Lab Manual

Bangalore Institute of Technology, Bangalore 29

REGULATED POWER SUPPLY

AIM: To implement a +5V regulated power supply using full-wave rectifier and 7805 IC regulator in

simulation package. Find the output ripple for different values of load current.

V

R 1

220

V

D 2

D 1N 4002

C 1

47uf

D 5D 1N 4002

0

D 4

D 1N 4002

D 1

D 1N 750

R 2

1K

V1

F R EQ = 60H zVAMPL = 10VVOF F = 0V

D 3D 1N 4002

TYPE OF ANALYSIS : TIME DOMAINRUN TO TIME : 100msMAXIMUM STEP SIZE: 0.1ms