EL 342 ELECTRONICS II
INSTRUCTOR: MISS YUM
LAB # 2
Statistical Hypothesis Testing to determine the temperature (heat) effect on the Parameter β (hfe) of
Bipolar Junction Transistors (BJTs)
OBJECTIVES:
1.
2.
3.
4.
5.
6.
To perform experiment to collect IC and IB before and after heat treatment
To determine Parameter β (hfe) based on IC and IB before and after heat treatment
To apply statistical analysis on “before and after” treatment data pairs samples
To draw conclusion about the difference between the two sample means
To establish the null and alternate hypotheses
To apply hypothesis testing
Background:
Hypothesis testing is a powerful technique uses by many scientists, researchers and engineers to
make a decision concerning the value of a parameter. Hypothesis testing concerns only one set of
sample data is very common, however, many statistical application employs paired data samples
to draw conclusions about the difference between two population means. Data pairs happen very
naturally in “before and after” situations, where the same “object of investigation” is measured
both before and after a treatment.
I: Definition
Paired data sample is obtained when the same “object of investigation” in this case the same NPN
BJT has undergone before (room temperature) and after (heat transmitted from body between two
fingers) treatment.
II: Experimental BJT Test Circuit
III: Set up Test Procedures
(1) Measure all resistors namely RB1, RB2, RC, and record them in an Excel file.
(2) Set VCC to 10V, measure the exact value of VCC and record it in the Excel file.
(3) Adjust the 10KΩ potentiometer until VCE is 5V.
(4) Measure and record the exact values of VA, VB, and VCE in the Excel file (before: room temp).
(5) Hold the BJT between your fingers (Heater) for two minutes without disturbing the rest of the
circuit. Heater, you are transmitting your body heat to the BJT under test.
(6) Measure and record the exact values of VA, VB, and VCE in the Excel file (after: heat treatment)
(7) Remove and replace the tested BJT with another BJT sample that you may obtain from the Sample
controller. Sample controller tape the tested BJT on a large sheet of paper and label the sample#.
(8) Repeat step (3) to (7) until all the samples are tested.
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EL 342 ELECTRONICS II
INSTRUCTOR: MISS YUM
Table 1: Assigned Groups and individual responsibility
Description of Responsibility
Group#1
Data controller: Create Excel File, record
William
measurement and enter equations for calculations
of β (hfe) based on the experimental data
Sample Controller: Control Samples & assist
Matt
Circuit Setup person (heater)
Heater, Circuit Setup & test BJTs: Set up Circuit,
Huang
perform experiment to obtain IB and IC before and
after heat treatment of BJT
Group#2
Andrew
Group#3
Kenley
Group#4
Luke
Samantha
Chris
Luke
Todd
Joonsoo
Brady
Miss Yum’s Comments:
In order to perform the experiment smoothly as a team each student is assigned to a specific responsibility as depicted in Table 1.
Each student is encouraged to work with your team members without reservation. A good team is like a well-oiled machine that runs
smoothly and seamlessly.
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