Different Types Comparators And Its Working

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What is a Comparator? Types of Comparators
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What is a Comparator? Types of Comparators
Introduction

• Comparators play an essential role in designing
  electrical and electronic projects. In electronic
  circuits, an op-amp is used with negative
  feedback and it can also be used as a comparator.
  The comparator is mainly designed without
  feedback for open loop configuration. These are
  widely used in A/D converters. When the i/p
  signal is sampled, then this signal is applied to
  multiple comparators to convert the digital form
  from analog.

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What is a Comparator? Types of Comparators
What is a Comparator?

• A comparator is defined as, a device which
  includes two i/p terminals namely inverting and
  non inverting terminals.
• One input terminal is fed with reference i/p
  signal and the remaining i/p is fed with the
  actual values of the signal. 
• The o/p signal can be generated based on the
  difference between two i/p signals either high or
  low.
• Here low and high signals are denoted by 0 and 1.

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What is a Comparator? Types of Comparators
What is a Comparator?

• The main purpose of the comparator is to compare
  two currents or voltages.
• It fed to the two i/p signals and generates
  binary digital o/p signal that specifies which is
  greater is called as a comparator.
• The two i/p terminals of the comparators are V
  and V- and the digital o/p is V0.
• This o/p signal can be defined as
• If V is greater than V- then V0 1and
• If V is less than V- then V0 0,

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What is a Comparator? Types of Comparators
Types of Comparators
Comparators are classified into different types
such as

• Mechanical Comparator
• Mechanical-Optical Comparator
• Reed Type Comparator
• Electrical-Electronic Comparator
• Pneumatic Comparator

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What is a Comparator? Types of Comparators
Mechanical Comparator
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What is a Comparator? Types of Comparators
Mechanical Comparator

• The mechanical comparator comprises the following
  parts

• Spring
• Pointer
• Pointer Attachment Fitting
• Damping Lever
• Measurement Spindle

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What is a Comparator? Types of Comparators
Mechanical Comparator

• The mechanical comparator is also called as
  microcator.
• In mechanical comparators, magnification is
  achieved by various mechanical devices and
  mechanical linkages. 
• Mechanical comparator is a measuring instrument.
• The mechanism of this instrument is in the form
  of tape spring twisted, and that is positioned in
  the middle part.
• The middle part of the mechanical comparator
  rotates through a fixed angle upon tension.

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What is a Comparator? Types of Comparators
Mechanical Comparator

• Mechanical comparators are classified into four
  types such as

• Dial Gauge Comparator
• Johansson Mikrokator Comparator
• Reed Type Comparator
• Sigma Comparator.

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What is a Comparator? Types of Comparators
Advantage

• Mechanical Comparator Less costly as compared to
  other devices.
• Instrument do not require any external agency
  like air or electricity.
• Usually mechanical Comparators have linear
  scales.
• They are compact in design They are easily
  portable

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What is a Comparator? Types of Comparators
Mechanical-Optical Comparator

• In this comparator a small dislocation of the
  measuring plunger is first amplified by a
  mechanical system comprising of pivoted levers.
• The mechanical movement which is amplified by an
  optical system connecting the outcrop an image. 
• The general arrangement of mechanical system
  causes a reflector to angle near the image 
• An axis of an index estimated on a scale on the
  inner glass screen. 
• Optical magnification offers a high degree of
  precision measuring.

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What is a Comparator? Types of Comparators
Mechanical-Optical Comparator
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What is a Comparator? Types of Comparators
Mechanical-Optical Comparator

• In this system, the mechanical amplification is
  multiplied by optical amplification. 
• if the mirror is sloped by an angle 60, then the
  image will be sloped by 266.
• Therefore, the total magnification of the system
  is 2 x (Zi) (J4//3).
• The optical comparators are proficient of giving
  a high degree of calculating accuracy.
• It is because of high magnification the
  discount off moving members to a minimum.

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What is a Comparator? Types of Comparators
Mechanical-Optical Comparator

• In this type of comparator, front reflection type
  mirror is used instead of normal back reflection
  type mirror.
• In normal back reflection mirror type, there are
  two reflected images such as front and back.
• One image is bright and other one is blurred both
  are observed.
• The main advantage of this comparator is that
  deliver of an illumined scale allows readings to
  be taken without favour to the conditions of room
  lighting.

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What is a Comparator? Types of Comparators
Reed Type Comparator
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What Is a Comparator? Types of Comparators
Reed Type Comparator

• This is a frictionless device for expanding small
  motions of the spindle. 
• It comprises of a static block A, which is
  strictly attached to the gauge head case.
• The floating block B carries the gauging spindle
  is connected horizontally to the static block
  by reeds C. 
• A perpendicular reed is attached to every block
  with the higher ends combined together

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What is a Comparator? Types of Comparators
Reed Type Comparator

• A linear motion of the spindle travels the free
  block perpendicularly causing the perpendicular
  reed to slide.
• This effort roots the target to swing through an
  arc over the scale related to the distance moved
  by the spindle. 
• This type of comparators may have the compassions
  of the order of 0.25 micro/scale division.

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What is a Comparator? Types of Comparators
Electric Comparators

• In this comparator, the measuring contact
  movement is changed into an electrical signal.
• Then this signal is recorded by a device that can
  be adjusted in terms of plunger movement. 
• For this, an AC Wheatstone bridge circuit
  including a galvanometer is used.
• This electric comparator comprises of a tough
  stylus, an iron armature.

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What is a Comparator? Types of Comparators
Electric Comparators

• It breaks against the W and spring and W1.
• If the armature is located between the coils W
  W1, then the inductance of these coils is equal.
• The Wheatstone bridge is stable and forms the
  datum line.
• When the work piece is located under the stylus
  for the measurement purpose due to the difference
  in datum. 
• The armature, component size would either be
  raised up or down. 

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What is a Comparator? Types of Comparators
Electric Comparators

• It defeats the Wheatstone bridge balance that
  results the unbalanced current flow. 
• This current is directly adjusted into difference
  in size of the component which is expanded by an
  amplifier specified by the galvanometer.
• This current is directly adjusted into difference
  in size of the component which is expanded by an
  amplifier specified by the galvanometer.
• The main advantages of these comparators are no
  moving parts, sensitivity and accuracy over long
  periods.

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What is a Comparator? Types of Comparators
Electric Comparators

• An electrical comparator consists of as follows

• Base a stand.
• Power unit.
• Measuring unit.
• Indication unit.
• Amplification unit.

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What is a Comparator? Types of Comparators
Pneumatic Comparator
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What is a Comparator? Types of Comparators
Pneumatic Comparator
The working principle of pneumatic comparator

• When the air under constant pressure discharges
  by passing through two openings.
•  If one of the hole is kept uniform, the pressure
  will change according to the size of the other. 
• The tube 1is connected to an air supply via
  restriction jets2 to pipe 11.
• Which dips into water in a deep vessel open to
  the atmosphere. 

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What is a Comparator? Types of Comparators
Pneumatic Comparator

• Air flowing at tube 1 increases in pipe 11 and
  keeps a fixed head of water-H and extra of air
  outflows as bubbles.
• Air from pipe11 flows through control jet3
  finally outflows through the measuring jet at 6.
• The pressure in the tube b/n control jet 3 and
  calculating jet6 will depend on the orifice size
  at 6.
• It is controlled by the distance b/n the
  measuring table and face.
• It is replicated by the height of a liquid in the
  manometer pipe8. 

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What is a Comparator? Types of Comparators
Pneumatic Comparator

• The scale 9 is also adjusted that a head
  difference h specifies changes in the gap d
  enlarged various hundred times. 
• The main advantages of this comparator is, easy
  to operate, cheap, independent of the constant
  pressure.
• It is free from mechanical wear and magnification
  is high as 10,000 times.

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What is a Comparator? Types of Comparators
Applications of Comparators

• Mainly involve in BLDC operating motors.
• Zero crossing detectors.
• Switching power regulators.
• Peak detectors.

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What is a Comparator? Types of Comparators
Conclusion

• This is all about a comparator and the types of
  comparators and its wide applications. A
  comparator compares two analog signals and
  produces a one bit digital signal.

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