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TOPIC: DISPLACEMENT MEASUREMENT. PRESENTED BY: SURESH VENKATTU ROLL NO: 1817. Displacement Measurement. Potentiometer Capacitive Transducer.
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TOPIC: DISPLACEMENT MEASUREMENT PRESENTED BY: SURESH VENKATTU ROLL NO: 1817
Displacement Measurement • Potentiometer • Capacitive Transducer. • Rotary variable differential transformer (RVDT)\ Linear Variable-DifferentialTransformer (LVDT)
POTENTIOMETER Linear potentiometer is a device in which the resistance varies as a function of the position of a slider.
Audio control. APPLICATION OF POTENTIOMETER Motion control. Television.
ADVANTAGES OFPOTENTIOMETER Inexpensive. Simple to operate. Useful for measurement of large amplitudes of displacement. Electrical efficiency is very high.
For linear potentiometer , a large force is required to move the sliding contact. DISADVANTAGE OFPOTENTIOMETER The sliding contacts can wear out It generates noise.
Capacitive Transducer The capacitance of the capacitor varies as the material comes between two plates of capacitor and the presence of something is measured by capacitance.
ADVANTAGES • OF Capacitive • Transducer It has very high sensitivity. Cost of transducer is low. Construction is simple.
Rotary variable differential transformer(RVDT) A=Primary windingB=Secondary winging
Linear Variable-DifferentialTransformer (LVDT) Vo=V1-V2 V1 V2 X=0 V2 = V1 Both the secondary windings are equal which results in net output is equal to zero Vi
Linear Variable-DifferentialTransformer (LVDT)(while moving left) Vo=V1-V2 V1 V2 -x V1 > V2 the emf voltage induced in the secondary coil is greater when compared to the emf induced in the secondary coil 2. Vi
Linear Variable-DifferentialTransformer (LVDT)(while moving right) Vo=V1-V2 V1 V2 +x V2 > V1 The emf induced in the secondary coil 2 is greater when compared to the emf voltage induced in the secondary coil Vi