# EC1262 Electronic Devices Circuits Lab Syllabus

EC 1262 ELECTRONIC DEVICES AND CIRCUITS LABORATORY 0 0 3 100

AIM
To study the characteristics and to determine the device parameters of various solid-state devices.

1. Static Characteristics of transistor under CE, CB, CC and determination of hybrid parameters.

2. Static characteristics and parameter determination of JFET.

3. Static characteristics of semiconductor diode, zener diode and study of simple voltage regulator circuits.

4. Static characteristics of UJT and its application as a relaxation oscillator.

5. Photodiode, Phototransistor characteristics and study of light activated relay circuit.

6. Static characteristics of
Thermistors.

7. Single phase half wave and full wave rectifiers with inductive and capacitive filters.

8. Phase shift oscillators and Wien bridge oscillators.

9. Frequency response of common emitter amplifiers.

10. Differential amplifiers using FET.
P = 45 Total = 45
Detailed Syllabus

1. Static Characteristics of transistor under CE, CB, CC and determination of hybrid parameters

Aim
To determine the static characteristics of transistor under CE, CB, CC mode.

Exercise

a. Plot the BJT CE, CB and CC input and output characteristics.

b. Determine the h-parameters hi, ho, hr and hf for CE, CB and CC characteristics from I/P and O/P characteristics.

2. Static characteristics and parameter determination of JFET

Aim
To determine the static characteristics of JFET

Exercise
1. Plot the JFET drain characteristics from the results obtained

2. Plot the JFET transfer characteristics from the results obtained.

3. From the drain characteristics for VGS = 0 determine the value of the rD and YOS parameters.

4. From the transfer characteristic, determine the values of the Yfs parameters at VGS =-1 V and VGS = - 4V.

5. Draw horizontal and vertical scales on the drain characteristics plotted by the XY recorder. Identify each characteristic according to the VGS level. Also, print the JFET type number on the characteristics.

3. Static characteristics of semiconductor diode, zener diode and study of simple voltage regulator circuits

Aim

1. To determine the static characteristics of semiconductor diode and zener diode

2. To study the simple voltage regulator circuits as Op-amp voltage regulator, source effect and load effect measurement, use of current limiter.

Exercise
Semiconductor diode

1. Plot the forward characteristic of the low – current diode and rectifier diode from the results obtained.

2. From the forward characteristics, determine the approximate forward voltage drop and dc forward resistance for D2 and for D2. Also estimate the ac resistance for each diode.

3. Comment on the results of reverse biased diode current measurements.

Zener diode

a. Plot a graph showing the Zener diode reverse characteristics.

b. From the Zener diode reverse characteristics determine the reverse voltage at IZ = 20 mA. Also determine the dynamic impedance for the device.

c. Calculate the line regulation, load regulation and ripple reduction factor produced by the Zener diode regulator.

Voltage regulator

1. Analyze the voltage regulator circuit for ripple reduction, source effect and load
effect. Compare the calculated and measured circuit performance.

2. Plot the regulator current limiting characteristics. Analyze the two current limiter circuits and compare the calculated and measured circuit performances.

4. Static characteristics of UJT and its application as a relaxation oscillator
Aim
To determine the static characteristics of UJT.

Exercise

1. Plot the UJT characteristics from the results obtained.

2. Calculate the intrinsic stand – off ratio from the results obtained.

3. Compare the calculated value with the specified value for the UJT.

4. Discuss the waveforms obtained for the UJT relaxation oscillator investigated. Compare the operating frequency with that calculated frequency.

5. Photodiode, Phototransistor characteristics and study of light activated relay
circuit

Aim
1. To draw the characteristics of photodiode, phototransistor.

2. To study the light activated relay circuit.

Exercise
Photodiode
1. Plot the photodiode reverse current upon different level of illumination.

2. Draw the dc load line for the circuit and determine the diode currents and voltages at different level of illumination.

Phototransistor
1. Draw the output characteristics IC / VCE of a phototransistor and determine the output voltage at different illumination levels.

2. Bias Phototransistor as a switch. Illuminate the phototransistor to activate a relay.

6. Static characteristics of Thermistors

Aim
To determine the static characteristics of thermistors.

Exercise
1. Draw the resistance / temperature characteristic of a thermistor and determine the resistance value for variations in temperature.

2. Draw the static voltage / current characteristics of a thermistor and determine whether device resistance remains constant until power dissipation is large enough to produce self-heating.

3. Use the thermistor as a temperature-compensating device by increasing the resistance with increasing temperature.

7. Single phase half wave and full wave rectifiers with inductive and capacitive
filters

Aim
To construct half wave and full wave rectifiers and to draw their input and output
waveforms.

Exercise
1. Plot the input and output waveforms and explain the difference between the
two.

2. Explain the effect of open – circuiting of any one diode.

2. Measure the PIV of two-diode full wave rectifier to the bridge rectifier.

3. Calculate the ripple factor of output waveform of inductive and capacitive filter and compare it with measured practical values.

8. Phase shift oscillators and Wien bridge oscillators
Aim
To construct the phase shift oscillator and Wien bridge oscillators and to draw its
output waveforms.
Exercise
1. Discuss the phase shift oscillator and Wien bridge oscillator output waveforms obtained from the experiment. Analyze the circuits and compare the calculated and measured frequencies.

2. Change the capacitor values and discuss the results.

3. Analyze the diode amplitude stabilization circuit for the Wien bridge oscillator and compare the calculated output amplitude to that of the measured values.
9. Frequency response of common emitter amplifiers
Aim
To determine the frequency response of common emitter amplifiers.

Exercise
1. For different values of cut – off frequencies determine suitable values of resistors and capacitors for common emitter amplifiers.

2. Plot the frequency response and determine 3dB bandwidth.

10. Differential amplifiers using FET
Aim
To analyse the characteristics of differential amplifier circuit using FET

Exercise
1. Construct the circuit and