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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
amplifier.ppt
- WELCOME
- AMPLIFIERS Presenter lavanya v
- 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
- 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
- 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 After filtering , the original signal is recovered as V2 With gain G=V2/V1 V1 V2 input output Vi V0 Chopper
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