Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong [email protected] 1 Basic...
Transcript of Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong [email protected] 1 Basic...
![Page 1: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/1.jpg)
Asst. Prof. Dr. Prapun [email protected]
1
Basic Elec. Engr. Lab ECS 204
Lab 5• RC Circuit with Voltage Step Input• Frequency Response of Series RLC Circuit • AC vs DC modes of the Oscilloscope• AC vs DC modes of the DMM• Function generator: Offset
![Page 2: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/2.jpg)
Triggering
2
![Page 3: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/3.jpg)
Triggering
3
Here, originally, the trigger level was set too high at around 5V so the trigger mechanism can’t “see” the signal. We then use the trigger level knob to adjust the trigger level to around 2.8V which stabilizes the display.
![Page 4: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/4.jpg)
Triggering
4
![Page 5: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/5.jpg)
Triggering
5
Trigger controls
![Page 6: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/6.jpg)
50 inside the function generator
6
Set the (open-circuit) voltage across the output of the signal generator at 6Vp-p.
Connect the generator output across a 100Ω resistor.
Measure the voltage across the generator again.
When nothing is connected across the function generator’s output, Vo = Voc.
Here, Vo is set to be 6 Vp-p. So, Voc is also 6 Vp-p.
When a 100 resistor is connected across the function generator’s output, Voc is split between the 50 inside and the 100.
If you did not adjust the function generator, then Voc is
still at 6 Vp-p and Vo 6 4Vp-p.
![Page 7: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/7.jpg)
50 inside the function generator
7
Ch 1: VG
Ch 2: V2
Ch 2 GND
Ch 1 GND
R1
R2
In lab 4, ….
![Page 8: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/8.jpg)
50 inside the function generator
8
Ch 1: VG
Ch 2: V2
Ch 2 GND
Ch 1 GND
R1
R2
In lab 4, ….
![Page 9: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/9.jpg)
All ground clips should be together
9
Ch 1: VG
Ch 2: V2
Ch 2 GND
Ch 1 GND
R1
R2
![Page 10: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/10.jpg)
Ex: Wrong measurement of V1
10
Ch 2 GND
Ch 1 GND
Ch 1: VG
Ch 2: V1?R1
R2
An attempt to use CH2 to measure V1.
![Page 11: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/11.jpg)
Ex: Wrong measurement of V1
11
Ch 2 GND
Ch 1 GND
Ch 1: VG
Ch 2: V1?R1
R2
![Page 12: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/12.jpg)
Ex: Correct measurement of V1
12
Ch 1
Ch 2
Ch 2 GND
Ch 1 GND
R1
R2
CH1 CH2V VUse to measure the voltage across any pair of nodes in the circuit
while still keeping the ground clips together. Differential Measurement
![Page 13: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/13.jpg)
Part A: RC Circuit
13
1k
0.1 F
Voltage across the generator output.
Voltage across the capacitor.
Square wave!Not sinusoid!
![Page 14: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/14.jpg)
RC Circuit with Voltage Step Input
14
0out inout
v t v tdC v tdt R
Assume the input voltage vin(t) is fixed at a particular value VS
from time t1 to t2.
1
1 1 2,t t
out S out Sv t V v t V e t t t
RC
in
out
(DE)
iCiC iR
iR
![Page 15: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/15.jpg)
Charging vs. Discharging
15
1
1 1 2,t t
out S out Sv t V v t V e t t t
RC
1
1 0
1
out
t t
out S
v t
v t V e
Chargingt1 t2
![Page 16: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/16.jpg)
Charging vs. Discharging
16
1
1 1 2,t t
out S out Sv t V v t V e t t t
RC
1
1
0St t
out out
V
v t v t e
Dischargingt1
![Page 17: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/17.jpg)
Charging vs. Discharging
17
1
1 1 2,t t
out S out Sv t V v t V e t t t
RC
1
1
0St t
out out
V
v t v t e
1
1 0
1
out
t t
out S
v t
v t V e
Charging Dischargingt1 t1
![Page 18: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/18.jpg)
Demo: DC Offset
18
no-offset OffsetVoutv t v t
Note: the ground level of the oscilloscope stays at the same place on the screen.
![Page 19: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/19.jpg)
4 Vp-p Square Wave
19
2V
-2V
Ground level
4V
Ground level
No DC OFFSET
With 2V DC OFFSET
t
t
![Page 20: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/20.jpg)
DMM: DC vs. AC Modes
20
VDC = Measured value of the voltage using DMM in DC mode Theoretically, VDC = Average value = DC offset voltage = DC component
VAC = Measured value of the voltage using DMM in AC mode Theoretically, for “True RMS” DMM,
For non-true-rms DMM, the measurement is calibrated so that the above property hold for sinusoids.
Theoretically,
0
0
DC1V
t T
t
v t v t dtT
0
0
2 2 2 2RMS AC DC
1V V Vt T
t
v t v t dtT
2AC DCV Vv t
![Page 21: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/21.jpg)
DMM: DC vs. AC Modes
21
VDC = Measured value of the voltage using DMM in DC mode Theoretically, VDC = Average value = DC offset voltage = DC component
VAC = Measured value of the voltage using DMM in AC mode Theoretically, for “True RMS” DMM,
For non-true-rms DMM, the measurement is calibrated so that the above property hold for sinusoids.
Theoretically,
0
0
DC1V
t T
t
v t v t dtT
0
0
2 2 2 2RMS AC DC
1V V Vt T
t
v t v t dtT
2AC DCV Vv t
Same when VDC = 0.This is why, in lab 4, VAC = Vrms.
![Page 22: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/22.jpg)
Square Wave
22
Ground level
Voffset = VDC
VP-PVAC
For square waveform (w/ or w/o DC offset), p-pAC
VV
2
“True rms”
p-pAC
VV
22 2
“Rectified average”
![Page 23: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/23.jpg)
Oscilloscope: DC vs. AC Modes
23
Input signal:
DC mode: Show
AC mode: Show vAC(t) always have 0 average (theoretically)
when VDC = 0.
v t
DCVACv t v t
DCv t v t
AC DCv t v t
![Page 24: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/24.jpg)
Part A: Find
24
Three different methods:
Measure t0.37.
Measure thalf. Then, calculate
Measure R and C. Then, calculate
= RC. 04 V
02 2V 01 .4 7 V e
h a lft 0 .3 7t
half ln 2t
00.37V
1k
0.1 F
0
t
outv t V e
![Page 25: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/25.jpg)
Part B.1
25
0V
0 2V
RV
01
2f
LC
R2Sine-wavegenerator
LC
8 Vp-p
22 mH
0.01 F0.47 F [474]0.1 F [104]
OscilloscopeCh-1 Ch-2
100
![Page 26: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/26.jpg)
Part B.2
26
f0 f
![Page 27: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/27.jpg)
Peak-to-peak reading from the scope
27
![Page 28: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/28.jpg)
Peak-to-peak reading from the scope (1/3)
28
![Page 29: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/29.jpg)
Peak-to-peak reading from the scope (2/3)
29
![Page 30: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/30.jpg)
Peak-to-peak reading from the scope (3/3)
30
![Page 31: Basic Elec. Engr. Lab - t U Slides.pdfAsst. Prof. Dr. Prapun Suksompong prapun@siit.tu.ac.th 1 Basic Elec. Engr. Lab ECS 204 Lab 5 • RC Circuit with Voltage Step Input • Frequency](https://reader030.fdocuments.net/reader030/viewer/2022040316/5e26741ec87a2012355ba88b/html5/thumbnails/31.jpg)
Peak-to-peak reading from the scope
31