1st KEC Conference Proceedings| Volume I ISBN 978-9937-0-4872-9

KEC Conference September 27, 2018

ELECTRONICS TESTER
Krishna Sapkota Krishna Keshav Chaudhary
Department of Computer and Electronics Engineering Department of Computer and Electronics Engineering
KANTIPUR ENGINEERING COLLEGE KANTIPUR ENGINEERING COLLEGE
Kathmandu, Nepal Kathmandu, Nepal
krrish1061@gmail.com info.dreamlover@gmail.com

Ram Prasad Paudel Jivan Karki

Department of Computer and Electronics Engineering Department of Computer and Electronics Engineering
KANTIPUR ENGINEERING COLLEGE KANTIPUR ENGINEERING COLLEGE
Kathmandu, Nepal Kathmandu, Nepal
expertise.paudel@gmail.com jivankarki1205@gmail.com

Abstract—Electronics is the most sensitive part of any project customers and competitors [2]. TI engineers developed a Cen-
as the minor difference can result in failure. So, the electronic tralized Automatic Tester (CAT) transistor-testing machine in
component must be tested first, before they are used otherwise 1958. TIs Transistor and Component Tester (TACT) introduced
they, might be the reason for project failure. It is a tedious
work to debug the circuit and confirm whether the circuit is in 1962 served the company and its customers for many years.
creating the problem or the electronics component if the project One of the first integrated circuit testers offered commercially
produces undesirable results. Thus, this paper describes the idea was the Signetics Model 1420 [2]. Along with the time after
of the checking the electronics components. Electronics Tester is the innovation of first integrated circuit tester there came sev-
built around the Arduino mega as a micro-controller and a Nokia eral different IC’s testers some tester available commercially
LCD 5110 graphical LCD. The system is capable of testing digital
IC’s up to pin 20, 555 timer IC, IC 741 operational amplifiers, include GUT-7000 Linear IC, Model 570A Analog IC Tester,
Resistor, Capacitor, and Transistor. Model 575A Digital IC Tester, DICT 02 and DICT 03
Index Terms—Nokia LCD 5110, Digital IC, 555 timer IC, 741 Universal IC Testers. All these testers available commercially
Op-amp Electronics Tester, RJ45 cable, On board testing are not economical and an addition of new IC is not possible,
thus to overcome these kinds of problem digital IC Tester
I. I NTRODUCTION is integrated into Electronics Tester. It is capable of testing
different kind digital IC up to pin 20 in two modes i.e.
Electronics components like resistor, capacitor, diode, IC automatic and manual mode along with features of adding
(Integrated Circuit), etc. have the different configuration so, of new IC’s with a slight update on the database.
they have to be tested by a particular kind of testers which Electronics tester test digital IC by applying necessary
involves more complicated and time involved in it will also inputs to the gates of the IC to be tested, which is placed
be more. Thus, here’s an Electronics tester to overcome such in the ZIF socket, output response is received from the micro-
problem which can test resistor, capacitor, transistor, RJ45 controller and corresponding outputs are also accumulated
cable, different kinds of digital ICs and 555 timer IC and 741 by Arduino board where the output is compared with the
op-amp. functional or the logic table and if any discrepancy results, it
Dramatic improvement of integrated technology in IC man- displays the failure results on the LCD display screen. 741 op-
ufacturing is rapidly leading to exceedingly complex, multi- amp operates in comparator mode for testing and 555 timer IC
million transistor chips. All the functionalities of an electronic testing is integrated with capacitor testing. Resistor measure-
system are being integrated on a single chip in less than 2 ment is done by connecting an unknown resistor with a known
cm square silicon area. This growth is expected to continue resistor in series and then applying the voltage divider rule.
full force for the future years. With the increase of such Capacitance measurement uses two approaches first charging
integration densities and complexities, problems associated and discharging approach Arduino capacitance meter for the
with testing of ICs have become much more Complex and range 1pF to 100nF and second multivibrator approach for
acute [1]. IC testing have now become a front-end issue in the range 1µF to 1000µF. For the testing of Rj45 cable, they are
semiconductor world, which needs an effective solution with simply considered as the transmission path for the clock pulse
reliable performance. For the first two decades of the industry, generated and it simply checks the output sequence generated
semiconductor manufacturers custom-built most of their own in different pins of Rj45 when the input is given to the one end
tools and equipment in-house. In the early 1960s, Fairchild of a Rj45 cable. On the basis of that, it tells whether the cable
Semiconductor, Signetics, Texas Instruments, and others began is connected in straight through or cross-over connection and it
to sell their specialized semiconductor test equipment to their is operational or not. Transistor testing is carried through the

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measurement of forward bias voltage between Base-Emitter

and Base-Collector to distinguish between NPN and PNP Start

transistor.

II. M ETHODOLOGY
Choose test Mode
A. IC Testing
In IC testing mode, there are two different modes, i.e.
automatic and manual mode.
Automatic Mode: In this process, at the first number of pins of Input Pin Yes IS No Input Ic
an IC that undergoes testing is taken as input. The device then Automatic
Number number
Mode?
starts manifesting all the possible input signal to the IC and
takes backs each possible output. If the responses match the
output of a particular IC’s in the DATABASE, then it declares Test the Test the
that the IC is functioning properly. It also displays the truth condition condition
table of the IC that undergoes the testing procedure. If an IC
is being tested in automatic mode then it provides with the
possible name of the IC, that is included in the database after
comparing the results obtained. IC is Yes IS All Gate No Display ”GOOD”
”GOOD” Good? and ”BAD” Gate
Manual Mode: At first IC number is entered, after that it
applies each possible input for that IC defined and records the
output of that IC. If the output obtained matches the response
defined in the DATABASE for that IC, then the IC is declared
good otherwise, indicates the bad gate among the number of
gates in that IC. Furthermore, different kinds of digital ICs
other than logic gates can be tested with this device as the
logic gate is an elementary building block of a digital circuit Yes Show
so, the output is either 1’s or 0’s. Thus, comparing the output truth table
obtained from the applied input to the pre-defined response at Truth
DATABASE device confirms that, the digital IC under test is Table
No
of ”IC”
functioning well.
END
B. Resistance measurement
If an unknown resistor and the known resistor are connected
in series then using the voltage divider rule. we get Fig 1: Flowchart of the IC testing

R1
R2 = Vout × (1)
Vin − Vout
•if the positive forward voltage is found from Base to
Where, Emitter and Base to Collector, we assume a properly
R1 = known resistance functioning NPN
R2 = Unknown resistance • if the positive forward voltage is found from Emitter
Vin = input voltage to Base and Collector to Base, we assume a properly
Vout = output voltage functioning PNP
Thus, form above equation 1 calculation of resistance mea- • the forward voltage will be around 0.7V for silicon
surement can be done. For precision, range are provided i.e transistors
upto 2.2KΩ, 2.2KΩ to 22KΩ, 22KΩ to 220KΩ and upto or When the transistor is tested Electronics tester distinguish the
greater than 1M Ω. NPN or PNP transistor with its forward junction voltage.
C. Transistor Testing D. RJ45 cable Testing
A Bipolar junction transistor (BJT) can be considered a
The circuit of RJ45 tester circuit is built around most
back-to-back pair of diodes.
popular timer IC NE555 configured in astable multivibrator
• NPN have the common anode on the base mode which is designed to generate 1 Hz clock pulse and a
• PNP have the common cathode on the base decade counter IC CD4017B. The output is taken from pin
This arrangement gives rise to one technique for testing BJTs Q0 to Q3 (pin 3, 2, 4 and 7) which drive LED sequence. This
is to measure the forward voltage between Base-Emitter and output is connected to CON2 (RJ45 socket), through which
Base-Collector. clock pulse is sent and the returning pulse is connected to

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Fig 2: Circuit Diagram of RJ45 cable Testing

Fig 3: Circuit Diagram of Capacitor Measurement

the LED sequence as shown in figure 2. Simply, these wire is

treated as a transmission path for the clock pulse. The resistors Where, F= frequency generated in astable mode 555 timer IC.
R3 through R6 is used here as a current limiting resistor which For the testing of 555 timer IC a known value of the capacitor
limits or drop current flowing through individual LED. The is measured, if the device indicates the value of capacitor then
Reset pin (pin 15) of IC2 is connected to its own output pin a conclusion can be made that the 555 timer IC operated in
Q4 (pin 10). This is because in fifth clock pulse it will reset astable multivibrator is good.
the decade counter IC (IC2 ). If the RJ45 cable which is under
test is straight-through the LED1 , LED2 , LED3 and LED4 F. 741 Op-amp Testing
will glow in sequence. Similarly, for Crossover type LED2 , The op-amp IC 741 is a DC-coupled, high gain differential
LED3 , LED1 and LED4 will glow in sequence. The cable amplifier with external negative feedback. IC 741 is char-
which is to be tested is connected to the two connectors CON2 acterized by almost infinite open loop gain, almost infinite
and CON3 and observe the sequence of glowing LED. input impedance (2MΩ) and almost zero output impedance
(75Ω). IC741 can be used as an electronic integrator or
E. Capacitance Measurement and 555 Timer IC Testing differentiator, depending on the R-C network in the input and
feedback circuit. The circuit of operational amplifier 741 tester
Uses two approaches for capacitance measurement, i.e.
charging and discharging approach and multivibrator approach
Arduino capacitance meter. For measuring low-value capac-
itor charging and discharging approach and for measuring
high-value capacitor multivibrator approach. In the charging
and discharging approach, the capacitor is first charged and
discharged through a known resistor. Time constant(τ ) for a
capacitor
τ =R×C (2)

Where, R = Fixed value of resistor used for charging and

discharging of capacitor
C = Capacitance of capacitor
The time constant is defined as the time in which charge on
the capacitor goes to 63.2% of the maximum value of charge.
The Arduino board basically measures the time taken by the
capacitor to reach the 63.2% of its voltage when it is fully
charged and 36.8% of its voltage when it is fully discharged.
In multivibrator mode the timer 555 IC is used in astable mode.
In this mode output swing between high and low at constant
rate, i.e. frequency is generated. The value of capacitance can
be found by the use equation 3 Fig 4: Circuit Diagram of 741 Op-amp Testing

1.44
F requency = (3) comprises two diodes and very few passive components and
(R1 + 2R2 ) × C

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a 741 IC to be tested. All the components are connected as Table 3:

shown in circuit diagram figure 4. An LED is used to indicate T RUTH TABLE OF G ATE N O . 3
either IC is good or faulty. Blinking LED indicates IC is good. Input combination Expected output Observed
The IC to be tested is configured in a voltage comparator Input A Input B
0 0 0 0
mode. The voltage at pin 3 (non-inverting pin) is fixed where 0 1 0 1
the voltage at pin 2 (inverting pin) varying due to charging and 1 0 0 0
1 1 1 1
discharging of capacitor C1 . Where the battery is connected
to the circuit the voltage at pin 3 is high in comparison to
the voltage at pin 2 due to the charging of a capacitor, as a Table 4:
F INAL R ESULTS FOR BAD G ATE N O . 3
result, an output of IC becomes high and LED start to glow.
At this instant capacitor start to charge through the resistor Gate No. Result
R4 . When the charge (voltage) of the capacitor exceeds the 1 Good
2 Good
voltage at the inverting pin (pin 2), the output of IC becomes 3 Bad
LOW, as a result, LED stop to glow. When the voltage at the 4 Good
capacitor becomes higher than inverting input pin it starts to
discharge and again the output of IC becomes high. This high
and low output of IC generates a square wave and cause LED
to blink. If the LED doesn’t blink in a fixed interval of time,
i.e. either stay ON or OFF the IC which is being tested is
faulty.
III. R ESULTS
IC Testing: Let us consider a 4000 series Digital 4081 IC.
It is a quad 2-input AND gate. If this IC is to be tested, then
Electronics Tester configured in IC testing mode implies each
and every possible combination input to the input pins of every
AND gate present in IC. Table 1 shows the truth table of an
Fig 5: Result of testing IC in automatic mode
Table 1:
T RUTH TABLE

Input combination Expected output Observed

Input A Input B
0 0 0 0
0 1 0 0
1 0 0 0
1 1 1 1

AND gate if the gate is fully operational. Truth Table for all
gates is shown and finally overall results is displayed. The

Table 2:
F INAL R ESULTS

Gate No. Result Fig 6: Result of testing of 4011 IC in manual mode

1 Good
2 Good
3 Good RJ45 cable testing: Rj45 cable are either connected in
4 Good straight through or cross-over connection and which connec-
tion they are connected can be checked by the device. If
above table 2 is the result when all gates of IC are good. If LED1 , LED2 , LED3 and LED4 glow in sequence, then it is
IC to be tested has a faulty gate no 3 then all other gates are straight through connection and if LED2 , LED3 , LED1 and
displayed good except gate number 3. LED4 will glow in sequence then it is cross-over connected
Rj45 cable. These sequences of glowing LEDs are obtained
when straight through and crossover cable are tested.
741 op-amp testing and 555 timer IC testing: When 741
op-amp IC is tested, then the LED (figure: 4) start blinking
which indicated that the 741 op-amp is good if the led not
blink then the IC is considered to be bad.
For 555 timer IC testing, when the electrolytic capacitor is

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measured and indicates some values, then it is concluded that

555 timer IC configured in astable mode is working correctly.
This result is obtained while testing a 555 timer IC.
Resistor, Capacitor and Transistor testing: Electronics tester
can test different values of the resistor and capacitor within
the percentage error of 5% while testing. Different ranges are
available for the testing of resistor and capacitor which has to
be selected, through a rotary switch. 5% of error is due to the
use of non-ideal components and in capacitance measurement
is due to the stray capacitance. Error percentage is evaluated
based on the values obtained from the resistor color code and
for capacitor from marked value and their values measured by
the device.
IV. C ONCLUSION
The idea to construct a device that could be helpful to
test the digital IC, 555 timer IC, 741 op-amps, resistor,
capacitor, RJ45 cable, and Transistor has been presented.
Based on the prototype testing, the proposed design could test
the functionality of IC’s when properly inserted in the ZIF
socket, properly test transistor, capacitor, resistor, 555 timer
IC, 741 op-amps and RJ45 cable. The prototype developing
process concluded that it is possible to develop an Electronics
Tester that can auto-detect the unknown logic device and able
to measure capacitor and resistor value within the tolerance
level and can successfully test the RJ45 cable and transistor.
Assisting with the implementation of the project of the system
with microcontroller makes the testing procedure simpler. So,
we can conclude that several electronic components can be
tested and any digital IC with the given specifications can
be implemented on Electronics Tester with the simplicity of
adding newer IC’s.
ACKNOWLEDGMENT
We would like to express our sincere thanks to Kantipur
Engineering College, for providing us the environment in the
research of project ELECTRONICS TESTER.
Our thanks are appreciations goes to our colleagues in the
development of the projects and people who have willingly
helped us out with their abilities.
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[2] I. A. Grout, Integrated circuit test engineering: modern techniques.
Springer Science & Business Media, 2005.
[3] B. Theraja, Fundamental Of Elect.Engg. & Electronics (M.E.). S. Chand
Limited, 2006.
[4] W. H. Buchsbaum and R. J. Prestopnik, Encyclopedia of integrated
circuits: a practical handbook of essential reference data. Business
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[5] J. Gupta, Electronic Devices And Circuits, ser. Katson Educational series.
S. K. Kataria & Sons, 2009.
[6] G. L. West, H. T. Nagle, and V. P. Nelson, “A microcomputer-controlled
testing system for digital integrated circuits,” IEEE Transactions on
Industrial Electronics and Control Instrumentation, no. 4, pp. 279–283,
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[7] F. V. Veen, “An introduction to ic testing,” IEEE Spectrum, vol. 8, no. 12,
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