Etron061L – Electronic Circuit Analysis and Design Laboratory
Experiment No. 3
!"# !iasing Circuits
$eneral %nstructions&
Before performing the experiment or handling any equipment, students should observe proper Occupational Health and Safety Procedures. Follo each and every procedure ritten on this experiment to achieve the desired results and to avoid ruining the experiment and!or the equipment being used. "fter the experiment, data should be chec#ed chec#ed by the laboratory instructor instructor for verification of the correctness of the students$ output. On the next meeting, an individual laboratory report ill be submitted that includes% the &ata and 'esults, "nser to (uestions, &ata "nalysis and Observations, and )onclusions on the experiment. 'b(ecti)es& *n performing this experiment, the students shall be able to% construct different biasing circuits of B+ dra the load line of the different biasing circuit #*eory + ,rinciple& !iasing is !iasing is the method of establishing predetermined voltages or currents at various points of an electronic circuit for the purpose of establishing proper operating conditions in electronic components. For transistor amplifiers the resulting dc current and voltage establish an operating point on the characteristics that define the region that ill be employed for amplification of the applied signal. Since the operating point is a fixed point on the characteristics, it is also called the -uiescent point -abbreviated (point/. By definition, quiescent means quiet, still, inactive. " B+ B+ circuit can be biased in so so many ays, here are some some of the biasing circuits% the the ixed/!ias Circuit Emitter/tabili2ed !ias Circuit oltage/Di)ider !ias Circuit and the DC !ias 4it* oltage eedbac5. eedbac5 . 0ach has its on characteristics, advantages, and disadvantages. he most significant difference beteen these biasing circuits is their stability ith respect to change in temperature or change in beta. " load line is is a graph on the output characteristics characteristics of a transistor hich hich represents the values of *) versus 1)0 of a particular resistance ') at different values of * B. *t is used to assess the operating point or (point of a transistor.
!"# !iasing Circuits
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Etron061L – Electronic Circuit Analysis and Design Laboratory
E-uipment + aterials Needed& E78%,EN# + A#E9%AL &igital rainer 3ultimeter 456789, 2#:, 4.4#:, 9.;#:, <#:, 28#:, 9;8#: )onnecting =ires
78AN#%#: 2 2 2 pc each 2 set
,rocedures&
Circuit 3/1. ixed/!ias Circuit.
Circuit 3/3. oltage/Di)ider !ias Circuit.
2. 4. 6. 9.
Circuit 3/;. Emitter/tabili2ed !ias Circuit.
Circuit 3/<. DC !ias 4it* oltage eedbac5.
)onstruct )ircuit 62. urn on the poer supply. 3easure *B, *), and *0. 'ecord the values in able 62. 3easure 1B0, 1)0, and 1). 'ecord the values in able 64. )ompute for the values of the quantities measured and compare it to the measured
values. <. &ra the load line of this circuit. *nclude the load line in &ata and 'esults. >. urn off the poer supply. )onstruct )ircuit 64. ;. urn on the poer supply. 'epeat steps 4 ? <. @. urn off the poer supply. )onstruct )ircuit 66. 7. urn on the poer supply. 'epeat steps 4 ? <. 28. urn off the poer supply. )onstruct )ircuit 69. 22. urn on the poer supply. 'epeat steps 4 ? <.
!"# !iasing Circuits
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Etron061L – Electronic Circuit Analysis and Design Laboratory
Data and 9esults& #able 3/1
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Currents o= Di==erent !"# !iasing Circuits.
Circui t 62
%! easured
%C Computed
%E Computed
easured
Computed
easured
64 66 69 #able 3/;
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oltages o= Di==erent !"# !iasing Circuits.
Circui t 62
!E easured
Computed
CE easured
Computed
C easured
Computed
64 66 69 7uestions& 2. &id your computed values match ith the measured valuesA *f yes, hat ould these values tell about biasing of B+A *f not, hat ould be the reason for such differenceA 4. Ho does the 9 biasing circuits differ from one anotherA
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