Experiment I47
AC Bridges
Calculations and Results
Part A Capacitance of capacitor
Frequency of signal generator: 1 kHz
For series-bridge
At bridge balance: C3 = 0.1 uF R3 = 150
R1= 1900 R2 = 30
The capacitance obtained: C = 6.33uF and R = 330
The dissip
Discussion
For capacitor, the power loss comes from the dissipation of energy of the flow of
current through the dielectric. In general the total impendence of the capacitor can be
written as
1
R( )
j C
,where R( ) is the resistance of the capacitor depe
Experiment I41
AC/DC converters
Objective
To study the basic principle of a digital to analog converter (DAC) and a counter-type
analog to digital converter (ADC)
Calculations and Results
Part A
D to A conversion
Table 1. Results of the measured resistanc
Discussion
The resolution in 4-bit ADC = 2 4 =16
The voltage resolution in 4-bit ADC =
full scale voltage range 3
4 0.1875 (V/div)
no. of intervals
2
If the resolution should be increased 10 times better, the minimum
number of bit, N, of the ADC is requi
Experiment I36
Semiconductor Temperature Transducer
Objective
To study the voltage-current characteristics of a semiconductor diode, which can be
formed a temperature transducer, then use it to construct a thermometer.
Apparatus
Digital voltmeter (Model:
Table 2. Results of the op-amp output voltage against temperature
Thermometer
reading (C)
29
34
39
Output
voltage (mV)
0.82 1.13 1.40 1.76 2.25 2.83 3.67 4.79 6.22 7.85 9.08 11.94
Notices : 1) The error of reading the thermometer is
2) The error of readin
Experiment I35
Linear Variable Differential Transformer (LVDT)
Objective
To construct a simple linear variable differential transformer (LVDT) for
displacement transducer application, then calibrate its sensitivity and linear range.
Apparatus
LVDT assembl
Discussion
1 Why is it necessary to use iron core in the LVDT?
Iron core causes the internal magnetic domains of the iron to line up with the smaller
driving magnetic field produced by the current in the coil. It can increase the flux
through all of the c
Experiment HD1
R-C Low Pass Filter
Calculations and Results
Measured resistance of the resistor R = 1000.
Measured capacitance of the capacitor C = 0.107uF
Table 1. Results of the signal measurements of the low pass filter circuit
Nominal freq.
(Hz)
100
Experiment HD1
R-C Low Pass Filter
Calculations and Results
Measured resistance of the resistor R = 1000.
Measured capacitance of the capacitor C = 0.107uF
Table 1. Results of the signal measurements of the low pass filter circuit
Nominal freq.
(Hz)
100
Voltage (V)
10
5
0
-0.06
-0.04
-0.02
0
0.02
0.04
0.06
Time (s)
Figure 4. Waveform recorded at CD (switch open)
10
Voltage (V)
8
6
4
2
0
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
Time (s)
Figure 5. Waveform recorded at CD (switch close)
Discussion
In this experim
Experiment E40
Use of the Oscilloscope
Calculations and Results
Resistance of the resistor R = 1000.
Capacitance of the capacitor C = 0.1uF
Table 1. Results of the signal measurements of the RC circuit
Nominal freq. (Hz)
10
100
1k
Measured period (s)
0.1
Experiment E38
A.C. Meters
Calculations and Results
Part A
AC ammeter
Table 1. Results for calibration of ac ammeter with half-wave rectification
a.c.
ammeter
reading
(A)
0.030 0.060 0.090 0.120 0.150 0.180 0.210 0.240
d.c.
ammeter
reading
(A)
0.066 0.133
Calculations and Results
Part A
AC ammeter
Table 1. Results for calibration of ac ammeter with half-wave rectification
a.c.
ammeter
reading
(A)
0.030 0.060 0.090 0.120 0.150 0.180 0.210 0.240
d.c.
ammeter
reading
(A)
0.066 0.133 0.198 0.273 0.336 0.418 0.
Procedure
Part A AC ammeter (Half-wave and Full-wave rectification)
The circuit as shown in Figure 4 and 5 are connected to calibrate average and r.m.s
currents. The reading of the ac ammeters showed the r.m.s values of the input
current. The reading of t
Experiment E38
A.C. Meters
1
Objective
To measure the ac signals with moving coil meters
Introduction
The operation of a moving-coil meter depends on the unidirectional flow of currents
through its coil. Therefore, if it is to be used to measure alternati
Calculations and Results
Part A
AC ammeter
Table 1. Results for calibration of ac ammeter with half-wave rectification
a.c.
ammeter
reading
(A)
0.030 0.060 0.090 0.120 0.150 0.180 0.210 0.240
d.c.
ammeter
reading
(A)
0.066 0.133 0.198 0.273 0.336 0.418 0.
Discussion
In above results, the slopes of the graphs are all close but greater than the theoretical
values. It is mainly due to the reading error of the meter. The reading of the a.c. meter is
higher than the actual values. The reading of the d.c. meter
Part B Analysis of inductor
Measured resistance of resistor R = 1010. 1
Inductance of inductor L = 21mH
Table 2. Results of the measured voltages across the components
Applied Signal
Frequency / Hz
VRL
(V)
VL
(V)
VR
(V)
1001 1
5.2
0.4
5.1
9999 1
2.5
1.9
Experiment E15
Phasor Diagrams of RL and RC Circuits
Objective
To study the voltage-current characteristics of a semiconductor diode and which can
be formed a temperature transducer, then use it to construct a thermometer.
Apparatus
Signal generator (Mode
Discussion
What do the ad represent in both phasor diagrams as shown in Figure 4 and 5
respectively?
In reality, capacitor contain resistance component, it is because the dissipating energy
in capacitor. A real component introduces to the impendence of ca
Figure 5. Specimen X20 with 40X
magnification
Figure 6. Specimen X24 with 40X
magnification
Figure 7. Specimen X25 with 40X magnification
Conclusion
When the position of the core closes to the central of the coils, the output voltage is
linear to the disp
Experiment MS50 Microstructure in Steel
Objective
To study metals in microstructure level, and through the observation to identify and
relate the structure of the metals with its properties.
Apparatus
Metallurgical microscope (Model:, Serial No.:)
Metalli
Discussion
The phase diagram of Bi-Sn alloy obtained from experiment consists with the phase
diagram obtained from Internet. In experiment, the melting point of pure Bi is about
261 oC. The melting point of pure Sn is about 222 oC. The eutectic point for
Thermal analysis of the Bi-Sn system
Calculations and Results
Table 1. Recorded phase change temperature with different composition of Bi-Sn
o
o
wt% Sn
T1 ( C)
T2 ( C)
0
261
N/A
15
224
157
30
171
134
43
132
122
60
162
127
70
179
127
79
197
132
90
211
146
Experiment MS41
Thermal analysis of the Bi-Sn system
1
Objective
To construct the phase diagram of the Bi-Sn system through the method of thermal
analysis.
Introduction
Apparatus
10 crucibles with Bi-Sn alloys of known compositions
Electric heater
Type K
Discussion
The phase diagram of Bi-Sn alloy obtained from experiment consists with the phase
diagram obtained from Internet. In experiment, the melting point of pure Bi is about
261 oC. The melting point of pure Sn is about 222 oC. The eutectic point for
Experiment MS38
Tensile test of steel
Calculations and Results
Table 1. The parameter of the specimens before tensile test
Length lo
(mm)
Crosssectional
area So (m2)
Specimen
diameter
do (mm)
A
5.08
27.24
8.01 x 10-5
E
4.90
26.80
7.54 x 10-5
Table 2. Meas