Physics for Electrical Engineering: Unit I: Dielectric Materials and Insulation
Pyroelectric Crystals and their Applications
Ferroelectric energy convertor It is a device which converts heat energy into electrical energy based on pyro-electric effect.
PYROELECTRIC
CRYSTALS AND THEIR APPLICATIONS
(i)
The pyroelectric materials such as BaTiO3, LiNibo3, etc
are used to make very good infra-red detectors which can operate at room
temperature.
(ii)Materials
such as TGS, Triglycine sulphate NaNO2 and Jode of PZT, lead zirconate titanate
ceramics are used in the Quae construction of pyroelectric image tubes.
Ferroelectric energy convertor
It is a device which converts heat
energy into electrical energy based on pyro-electric effect.
Principle
The ferroelectric crystals exhibit
the phenomenon of pyroelectric effect, i.e., change in the temperature of the
crystal produces a change in its polarisation.
Using
this effect, one can convert heat energy into useful electrical energy.
Description
Ferroelectric
crystal BaTiO3 is placed in between two parallel plate capacitors C1and
C2 as shown in fig 1.36 (a).
The
capacitor and the crystal can be charged with the help of an external battery.
Initially,
the temperature of the system is kept at T1 K (just below the ferroelectric
curie temperature ' θ ') and the capacitor is charged to a
voltage V1.
Initial
energy (E1) = C1 V12 = area of the triangle abc fig
(b)
where C1 is the capacitance of the capacitor at T1 K.
Now,
the capacitor is separated from the circuit and it is heated upto temperature T2.
Due to heating, the dielectric constant εr decreases and the
capacitance also decreases.
Now,
when the capacitor is charged for the same value of charge as it in temperature
T, it is found that the voltage starts increasing from V1 to V2.
Increase in energy E2 = ½ C2 V22
Net increase in energy
∆
E = E2 - E1
=1/2
( C2V22 – C1 V12
)
This
increase in heat energy can be converted into electric power by discharging the
capacitor through the bond resistor R1
Physics for Electrical Engineering: Unit I: Dielectric Materials and Insulation : Tag: : - Pyroelectric Crystals and their Applications
Physics for Electrical Engineering: Unit I: Dielectric Materials and Insulation
Under Subject
Physics for Electrical Engineering
PH3202 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation
Related Subjects
Professional English II
HS3251 2nd Semester 2021 Regulation | 2nd Semester Common to all Dept 2021 Regulation
Statistics and Numerical Methods
MA3251 2nd Semester 2021 Regulation M2 Engineering Mathematics 2 | 2nd Semester Common to all Dept 2021 Regulation
Engineering Graphics
GE3251 eg 2nd semester | 2021 Regulation | 2nd Semester Common to all Dept 2021 Regulation
Physics for Electrical Engineering
PH3202 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation
Basic Civil and Mechanical Engineering
BE3255 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation
Electric Circuit Analysis
EE3251 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation
Physics for Electronics Engineering
PH3254 - Physics II - 2nd Semester - ECE Department - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation
Electrical and Instrumentation Engineering
BE3254 - 2nd Semester - ECE Dept - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation
Circuit Analysis
EC3251 - 2nd Semester - ECE Dept - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation
Materials Science
PH3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation
Basic Electrical and Electronics Engineering
BE3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation
Physics for Civil Engineering
PH3201 2021 Regulation | 2nd Semester Civil Dept 2021 Regulation
Basic Electrical, Electronics and Instrumentation Engineering
BE3252 2021 Regulation | 2nd Semester Civil Dept 2021 Regulation
Physics for Information Science
PH3256 2nd Semester CSE Dept | 2021 Regulation | 2nd Semester CSE Dept 2021 Regulation
Basic Electrical and Electronics Engineering
BE3251 2nd Semester CSE Dept 2021 | Regulation | 2nd Semester CSE Dept 2021 Regulation
Programming in C
CS3251 2nd Semester CSE Dept 2021 | Regulation | 2nd Semester CSE Dept 2021 Regulation