Introduction Amplifiers are intermediate element that the increase the magnitude of the signal from a transducer amp is an electronic device that can increase the power of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is a circuit that has a power gain greater than one. An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorized in different ways. One is by the frequency of the electronic signal being amplified. For example, audio amplifiers amplify signals in the audio (sound) range of less than 20 kHz, RF amplifiers amplify frequencies in the radio frequency range between 20 kHz and 300 GHz, and servo amplifiers and instrumentation amplifiers may work with very low frequencies down to direct current. Can be conveniently displayed or recorded In cases where a reduction is needed in the magnitude of the signal from the transducers called attenuators Types of amplifier Mechanical amplifying element Hydraulic amplifying amplifying element Pneumatic optical amplifying element Optical amplifying element Electrical amplifying element Instrumentation and measurement work Ac amplifier Dc or direct coupled amplifiers Carriers amplifier Chopper amplifier Pneumatic amplifying element In order to amplify pressure signal P2, a ball type relay which is operated by the motion of an elastic diaphragm which gets deflects due to P2 If the ball is at lowest position, pressure P3 is atmospheric while at the top most position P3 equals supply pressure P1 P3 changes from zero gage pressure to P1 due to small change in P2 Optical amplifying element A ray of light gets deflected by 2θ, from a mirror attached to the moving member and the distance X0 moved by the light spot on the scale X0=2Rθt R-distance between the scale and mirror AC and DC amplifier Input voltage V1 to be amplified, is supplied to grid of valve1 Voltage V2 from valve 1 is applied across the grid of valve 2 Coupling between the two valves is through a capacitor C, in case of an amplifier If the capacitor is omitted, the component of the signal is retained and it becomes a direct coupled amplifier Chopper amplifier The input signal is ,by a chopper, made to produce a square wave voltage The chopped or modulated signal is amplified by an ac amplifier The original signal is recovered by the demodulation and filtering For a dc voltage V1,the chopped voltage Vi to Vo are of square type and Toda

1. WELCOME

2. AMPLIFIERS
Presenter
lavanya v

3. Introduction
Amplifiers are intermediate element that the increase the
magnitude of the signal from a transducer
Can be conveniently displayed or recorded
In cases where a reduction is needed in the magnitude of the
signal from the transducers called attenuators

6. Types of amplifier
1) Mechanical amplifying element
2) Hydraulic amplifying amplifying element
3) Pneumatic optical amplifying element
4) Optical amplifying element
5) Electrical amplifying element
Instrumentation and measurement work
1) Ac amplifier
2) Dc or direct coupled amplifiers
3) Carriers amplifier
4) Chopper amplifier

7. Pneumatic amplifying element
 In order to amplify pressure
signal P2, a ball type relay
which is operated by the
motion of an elastic
diaphragm which gets
deflects due to P2
 If the ball is at lowest
position, pressure P3 is
atmospheric while at the top
most position
 P3 equals supply pressure P1
 P3 changes from zero gage
pressure to P1 due to small
change in P2

9. Optical amplifying element
 A ray of light gets deflected by
2θ, from a mirror attached to
the moving member and the
distance X0 moved by the light
spot on the scale
X0=2Rθt
R-distance between the scale
and mirror

11. AC and DC amplifier
 Input voltage V1 to be
amplified, is supplied to grid of
valve1
 Voltage V2 from valve 1 is
applied across the grid of valve
2
 Coupling between the two
valves is through a capacitor C,
in case of an amplifier
 If the capacitor is omitted, the
component of the signal is
retained and it becomes a direct
coupled amplifier

13. Chopper amplifier
 The input signal is ,by a chopper,
made to produce a square wave
voltage
 The chopped or modulated signal
is amplified by an ac amplifier
 The original signal is recovered by
the demodulation and filtering
 For a dc voltage V1,the chopped
voltage Vi to Vo are of square type
and
 After filtering , the original signal
is recovered as V2
With gain G=V2/V1
V1 V2
input
output
Vi V0
Chopper

15. Thank You