Generoso, Mark Railey Y. | 20830116
FINAL REPORT
Holy Angel University
School of Engineering and Architecture
Electrical Engineering Program
FUNDCKTSL
Laboratory Experiment #1
Laboratory Meters and Power Supply
Generoso, Mark Railey Y.
Initial – 8/3/2022
Final – 8/10/2022
CPE-201 | 4740 – W
Group Members:
Canoy, Mark Joshua
Generoso, Mark Railey
Fabian, Erica
Gonzales, Albert Miguel
Engr. Elmer Perez
Instructor
FUNDCKTSL Experiment No. 1: Laboratory Meters and Power Supply
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Generoso, Mark Railey Y. | 20830116
FINAL REPORT
HOLY ANGEL UNIVERSITY
Electrical Engineering Department
FUNDCKTS Laboratory Experiment No. 1: LABORATORY METERS AND POWER SUPPLY
INTRODUCTION
The measurement of electrical quantities such as voltage, current, and resistance is essential in determining
the circuit performance. These electrical quantities are measured using meters such as ammeters, voltmeters, and
ohmmeters. An ammeter is an instrument use to measure current. It should always be connected in series with the
circuit element in which current is to be measured. To avoid damage to the meter, an ammeter must never be
connected across a voltage source.
A voltmeter is an instrument use to measure voltage. It should always be connected in parallel with the circuit
element in which voltage is to be measured. An ohmmeter, on the other hand, is an instrument use to measure
resistance. It should always be connected across the circuit element in which resistance is to be measured. Never
attempt to measure resistance in an energized circuit.
A multimeter is a multipurpose measuring instrument that combines the characteristics of a voltmeter, an
ammeter, and an ohmmeter in one instrument. It can either be an analog volt-ohm-milliampere (VOM) or a digital
multimeter (DMM). An analog meter has primary and secondary divisions. A primary division is the one with a
number while secondary divisions are unnumbered marks between the primary divisions. In reading an analog
meter, always start by looking at the primary divisions on either side of the needle then determine what each
secondary mark is worth. When a voltage or current estimate is not known, always start at the highest range to
avoid instrument overload and possible damage.
A DMM indicates the measured quantity as a digital number thus avoiding the need to interpret the scales as
necessary for analog meters. It is also more accurate, simple to use, and more flexible than a VOM.
The Power Supply Module EMS 8821 provides all the necessary ac/dc power to perform all the experiments
presented in this manual. In this experiment you will study the use of the EMS 8821 Power Supply Module, the
ammeter, the voltmeter, and the ohmmeter.
OBJECTIVES
1. To operate the ac/dc power supply module.
2. To learn how to use an ammeter, a voltmeter, and an ohmmeter.
3. To read analog meter scales.
INSTRUMENTS AND COMPONENTS
Power Supply Module
AC Metering Module
DC Metering Module
Resistance Module
Analog Volt-Ohm-Milliammeter (VOM) or Digital Multimeter (DMM)
Connection leads
WARNING!
Since high voltages are present in this Laboratory Experiment, make certain that the Power Supply is OFF
before making any connections!
FUNDCKTSL Experiment No. 1: Laboratory Meters and Power Supply
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Generoso, Mark Railey Y. | 20830116
FINAL REPORT
PROCEDURE
POWER SUPPLY MODULE
1. Study the construction of the Power Supply Module EMS 8821. On the front panel of the module, identify the
following parts:
a) The three-pole circuit breaker on-off switch.
b) The three lamps indicating the operation of each phase.
c) The ac/dc voltmeter.
d) The ac/dc voltmeter selector switch.
e) The variable output control knob.
f) The fixed 120/208-volt output terminals (labeled 1, 2, 3 and N).
g) The variable 0-120/208 volt output terminals (labeled 4, 5, 6 and N).
h) The fixed dc output terminals (labeled 8 and N).
i) The variable dc output terminals (labeled 7 and N).
j) The common reset button.
2. For each of the following terminals, write on the space provided the rated voltage and current available, and
state whether if it is ac or dc:
a) Terminals 1 and N = _______V_______A______
b) Terminals 2 and N = _______V_______A______
c) Terminals 3 and N = _______V_______A______
d) Terminals 4 and N = _______V_______A______
e) Terminals 5 and N = _______V_______A______
f) Terminals 6 and N = _______V_______A______
g) Terminals 7 and N = _______V_______A______
h) Terminals 8 and N = _______V_______A______
i) Terminals 1 and 2 = _______V_______A______
j) Terminals 2 and 3 = _______V_______A______
k) Terminals 3 and 1 = _______V_______A______
l) Terminals 4 and 5 = _______V_______A______
m) Terminals 5 and 6 = _______V_______A______
n) Terminals 6 and 4 = _______V_______A______
Attach a photo of the power supply
FUNDCKTSL Experiment No. 1: Laboratory Meters and Power Supply
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Generoso, Mark Railey Y. | 20830116
FINAL REPORT
3. a) Place the voltmeter selector switch to its 7-N position and turn on the power supply by placing the on-off
switch in its “up” position.
b) Rotate the control knob clockwise and note that the dc voltage increases. Measure and record the
maximum dc output voltage as indicated by the built-in voltmeter.
Vdcmaximum = ___________
Attach a photo of the instrument
c) Return the voltage to zero by turning the control knob to its full counter-clockwise position.
4. a) Set the voltmeter selector switch into its 4-5 position.
b) Rotate the control knob clockwise and note that the ac voltage increases. Measure and record the maximum
ac output voltage as indicated by the built-in voltmeter.
Vacmaximum = ___________
Attach a photo of the instrument
c) Return the voltage to zero and turn off the power supply by placing the on-off switch in its “down” position.
5. a) Place the voltmeter selector switch to its 8-N position.
b) Turn on the power supply.
c) Measure and record the voltage.
Terminals 8 and N = __________ Vdc
Attach a photo of the instrument
d) Is this voltage affected by turning the control knob? _________
e) Turn off the power supply.
6. For each of the following positions of the voltmeter selector switch:
a) Turn on the power supply and rotate the control knob to its full clockwise position.
b) Measure and record the maximum voltage.
Terminals 5 and 6 = _____________ Vac
Terminals 6 and 4 = _____________ Vac
Terminals 4 and N = _____________ Vac
Terminals 5 and N = _____________ Vac
Terminals 6 and N = _____________ Vac
c) Return the voltage to zero and turn off the power supply.
FUNDCKTSL Experiment No. 1: Laboratory Meters and Power Supply
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Generoso, Mark Railey Y. | 20830116
FINAL REPORT
VOLTMETER
7. a) Connect the 250-Vac voltmeter across Terminals 1 and 2 of the Power Supply Module.
b) Turn on the power supply.
c) Measure and record the voltage.
Terminals 1 and 2 = _____________ Vac
Attach a photo of the instrument
d) Rotate the control knob and observe the meter pointer.
e) Turn off the power supply.
8. Repeat Procedure 7 for the following terminals:
Terminals 2 and 3 = _____________ Vac
Terminals 3 and 1 = _____________ Vac
Terminals 1 and N = _____________ Vac
Terminals 2 and N = _____________ Vac
Terminals 3 and N = _____________ Vac
Are any of the measured voltages of Procedures 7 and 8 affected by turning the control knob? ________
AMMETER
9. a) Connect the circuit shown in Figure 1-1.
Figure 1-1
Attach a photo of the connection
b) Turn on the power supply.
c) Slowly turn the control knob and observe the direction of the meter pointer.
d) Return the voltage to zero and turn off the power supply.
Does the pointer deflect in the positive direction? ______
10. a) Reconnect the circuit shown in Figure 1-1 by interchanging the polarity of the ammeter.
b) Turn on the power supply.
c) Slowly turn the control knob and observe the direction of the pointer.
d) Return the voltage to zero and turn off the power supply. Disconnect your circuit.
Does the pointer deflect in the positive direction? ______
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Why? ________________________________________________
Generoso, Mark Railey Y. | 20830116
FINAL REPORT
OHMMETER
11. Set your multimeter to measure resistance. If you are using a DMM, proceed right away to Step (c).
a) Set the multimeter to the highest resistance range available.
b) Touch the test probes of the meter together. When you do, the meter should register 0 Ω of resistance. Since
you are using an analog meter, you will notice the pointer deflect full-scale when the probes are touched
together and return to its resting position when the probes are pulled apart. The resistance scale on an
analog multimeter is reverse-printed from the other scales: zero resistance is indicated at the far right-hand
side of the scale, and infinite resistance is indicated at the far left-hand side. There should also be a small
adjustment knob or "wheel" on the analog multimeter to calibrate it for "zero" ohm of resistance. Touch
the test probes together and move this adjustment until the pointer exactly points to zero at the right-hand
end of the scale.
c) Using your multimeter, measure and record the resistance of the 200-Vdc voltmeter.
Resistance of the 200-Vdc voltmeter = ___________
Attach a photo of the instrument
d) Measure and record the resistance of the 5-Adc ammeter. If you are using a VOM, you may need to
adjust your setting to the lowest resistance range available in order to have an accurate reading.
Resistance of the 5-Adc ammeter = ____________
Attach a photo of the instrument
Does the voltmeter have appreciably higher resistance than the ammeter? _______
Why? _________________________________________________________
CHECK YOUR UNDERSTANDING
1. What will happen if an ammeter is connected in parallel with the circuit being measured? Why?
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If you try hooking up an ammeter parallel to the circuit, all the current will go through the
ammeter, which will overload it and eventually burn out. This is because the ammeter was
designed to have an almost non-existent resistance in order to not disturb the flow of current
in a certain path of the circuit it is trying to measure.
2. What will happen if a voltmeter is connected in series with the circuit being measured? Why?
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Hooking up a voltmeter in series to a circuit will almost zero out the current flowing
throughout the circuit, because voltmeter has a very high resistance which then acts as a big
resistor. Therefore, all the other circuit elements will receive almost no current due to
voltmeter hogging it all up. On a side note, voltmeter will not be damaged in this scenario,
unlike the ammeter hooked in parallel.
3. Assume a scale has nine secondary marks between the primary marks numbered 50 and 100. If the pointer
is on the second mark, what is the reading on the meter?
FUNDCKTSL Experiment No. 1: Laboratory Meters and Power Supply
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A visual representation:
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Its reading will fall on the 60.
Generoso, Mark Railey Y. | 20830116
FINAL REPORT
CONCLUSION
Our life is incomplete without electricity. We need electricity for every purpose, be it an
entertainment, working on a computer, using washing machines or escaping the summer heat with the
aid of air conditioners. Everything needs electricity to operate. However, we need to ensure whether
everything is working appropriately and accurately. In our brief discussion of electrical and electronic
circuits, the quantities in the circuit (voltage, current, and resistance) are important. If you can measure the
electrical quantities in a circuit, it is easier to understand what is happening in that circuit. This is especially true
when you are troubleshooting defective circuits. This necessitates the importance of electrical measuring
instruments.
Electrical measuring instruments as the name suggests are equipment used for gauging various
electrical aspects. These instruments measure the resistance or current, voltage, power, voltage
frequency, flux and so on. For this activity, we made used of Ammeter - a measuring instrument used
to measure direct or alternating electric current in an electric circuit, and a Voltmeter - used to measure
the hypothetical disparity between electrical and electronic circuit. It was also noted that we must be
careful on using these instruments, as it can result on unwanted results, such as the instrument breaking
down, or the circuit (in this case, the lab power supply) we’re working with may short out.
Electrical technicians and engineers have a wide variety of tools available. Some of these are
complex, often expensive tools for measuring one specific quantity, and if used properly, they can
return many times their cost with just one or two uses. In any electrical facility, be it commercial or
residential, electrical measuring instruments plays a potential role in measuring the electrical current.
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