good

1. INTRODUCTION TO MECHATRONICS
Chapter Three
Signal Conditioning

2. Data Acquisition System

3. Signal is a time /space varying quantity
that carries energy and information

4. • narrow band
switching at 6
kHz
• intermodulation
with 100 kHz
distortion which
is coming from
upstream
• tripping of
residual current
devices (RCD)
Source : Angela, Jil, Selcuk , Electromobility I Project - supraharmonics
Supraharmonics

5. • Amplification (mV → high energy level)
• Filtering
• Isolation and Protection
• Linearization
• Multiplexing
• ADC and DAC Processes
• Modulation
• Demodulation
Signal Conditioning Processes (3.2)
(Shaping and Manipulation of Signal)

6. Signal Manipulation and Conversion

7. • As a solid-state universal integrated circuit
(IC).
• As a versatile device in the field of electronics
with external feedback for controlling its
function and responses with a very high gain.
• As a basic fundamental component for the
design and development of analog electronic
circuits and devices, like analog computers.
Operational Amplifiers

8. Performs mathematical operations such as:
• summation,
• difference,
• logarithmic operation,
• Exponential
• integration,
• and differentiation.
Types of Op-amp
Amplifier, a filter, a
comparator, oscillator,
shifter, zero detector,
current to voltage
converter.
This device offers infinite
(1)/ high input impedance
and zero /low output
impedance.

9. ± 5V to ± 15V
• o/p terminal
High voltage
gain and
voltage
amplification

11. Inverting Op-amp

12. Non-inverting Op-amp

13. Difference Op-amp

14. Summing Op-amp

15. Differentiator Op-amp
𝑄 = 𝐶𝑉𝑖
𝑖𝑐 =
𝑑𝑄
𝑑𝑡
= 𝐶
𝑑𝑉𝑖
𝑑𝑡
= −𝐼𝑟

16. https://www.youtube.com/watch?v=jPMxF_qYZdg&t=276s

17. Integrator Op-amp
𝐼𝑟 = −𝑖𝑐
𝑉𝑖
𝑅
= −𝐶
𝑑𝑉𝑜
𝑑𝑡
𝑉𝑖
−𝑅𝐶
=
𝑑𝑉𝑜
𝑑𝑡
𝑉𝑜 = − න
0
𝑡
𝑉𝑖
𝑅𝐶
𝑑𝑡 + 𝑉𝑖𝑛𝑖𝑡𝑖𝑎𝑙
𝐺𝑓 =
𝑉𝑜
𝑉𝑖
= − න
0
𝑡
1
𝑅𝐶
𝑑𝑡

18. Comparators
• Determining higher or lower level of voltage
𝑉𝑖 > 𝑉𝑟𝑒𝑓 , 𝑉𝑑 = - ve , 𝑉
𝑜 = - 𝑉𝑠𝑎𝑡 ≅ −𝑉
𝑠
𝑉𝑖 < 𝑉𝑟𝑒𝑓 , 𝑉𝑑 = + ve , 𝑉
𝑜 = + 𝑉𝑠𝑎𝑡 ≅ +𝑉
𝑠
𝑉
𝑜 = A 𝑉𝑑 , 𝑉𝑑 = + 𝑉𝑟𝑒𝑓 - 𝑉𝑖
105
− 108

19. (a) Negative feedback (b) Positive feedback (c) Output Characteristics

20. • Revision of non inverting amplifier
Voltage follower (Unity gain amplifier)

21. • Revision of non inverting amplifier
Voltage follower (Unity gain amplifier)

22. Voltage follower

23. • Isolation of two circuits and used when the input
impedance of circuit 2 is small
• Eliminate loading effect of a buffer amplifier
• Circuit become unstable while driving a high capacity
load due to strong feedback. Hence load should be
connected with a resistor

24. Comparator Vs Schmitt Trigger

25. Comparator with noise

26. • Bi-stable multi-
vibrator (two
stable states)

28. Hysteresis Curve

29. Inverting Schmitt Trigger

30. • It is a process of removing a certain band
of frequencies from a signal (transducer
output signal) and allowing transmission
of other signals for amplification .
• The order of filter is determined by the
number of reactive components (L and C)
used in the filter design .
Filtering

31. Types of filters

33. 𝑓𝐻 =
1
2𝜋𝑅1𝐶1

34. 𝑓𝐿 =
1
2𝜋𝑅1𝐶1

35. 𝑓𝑏 = 𝑓𝐻 − 𝑓𝐿

36. 𝑅1 =
𝑄
2𝜋𝑓𝐶𝐺
𝑅2 =
𝑄
2𝜋𝑓𝐶(2𝑄2 − 𝐺)
𝑅3 =
𝑄
𝜋𝑓𝐶
𝑓 → 𝑐𝑒𝑛𝑡𝑟𝑒 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦, 𝑄 → 𝑄𝑢𝑎𝑙𝑖𝑡𝑦 𝑓𝑎𝑐𝑡𝑜𝑟, 𝐺 → 𝑔𝑎𝑖𝑛

38. Multiplexer
combinational circuit that has maximum of 2n data
inputs, ‘n’ selection lines and single output line.

39. 00
01
10
11
S1 S0 Y
0 0 Io
0 1 I1
1 0 I2
1 1 I3

40. • Op Amp requires protection against excessive
current, such as in cases of short circuit, over
voltage, electrostatic charges, and high common
differential voltage input.
• Designs of modern Op Amp offers protection
circuits at the cost of reduction in some of the
performances such as speed of operation,
dynamic range, and level of output signal swing.
• Op Amps requires protecting diodes along with
resistors at their input terminals .
Circuit protection

41. Protection
• Connection of Sensor to
microprocessor may
damage due to high
current or voltage – series
resistor or fuse.
• High voltage and wrong
polarity protection – Zener
diode.
• Zener diode has low
resistance for current in
one direction and high in
the opposite direction.
• Correct polarity gives high resistance across the
output and a high voltage drop. In reverse
connection Zener diode has low resistance and
little voltage drop across the output.

42. • Complete isolation and
remove electrical
connection – Optoisolator
• Output current to input
current – transfer ratio (TR)
• Photo transistor – o/p
current is smaller than i/p
current thus -TR 30%
• Darlington o/p current is
larger than i/p current - TR
800%
• Triac used with AC
• Triac with zero crossing
reduce transients and EMI
Rectification

43. Analog –to digital conversion
• Block diagram scheme of Analog to digital
converter.

45. 𝐴 = 𝜋𝑟2
Vo=[b5
1
𝑅
+b4
1
2𝑅
+..b0
1
32𝑅
] Rf*Vref

46. If the digital binary coded input for
a 4-bit word to a DAC is 1100, find
its equivalent analog value for a
reference voltage of 5 V.

47. Successive approximation ADC

48. Find the digital value for an S/A 4 bit
ADC, if the test transducer analog
output voltage fed to the ADC is 3.217 V
at a reference voltage of 5V.

49. • Determine the digital output pattern for an 8
bit ADC if the transducer output voltage for
digital conversion is Vin =1V and the reference
voltage is 5V. 00110011