Voltage dependent resistor, Physics

Assignment Help:

A VDR is a special type of resistor that changes its resistance with rise in voltage. It has a very high resistance at low voltage (below the trigger voltage) and very low resistance at high voltage (above the trigger voltage). It is also called varistor or voltage sensitive resistor. There are two types of varistor.

SILICON CARBIDE VARISTOR:-              

MANUFACTURING: These are made up of silicon carbide. It is milled and mixed with a suitable ceramic binder. Then it pressed and extruded to desired shape of disc, rod or washer. Then it is sintered under controlled temperature to produce hard material. Wire leads are then connected.

METAL-OXIDE VARISTOR (MOV):

MANUFACTURING:

 Zinc oxide and bismuth oxides are mixed with other powdered metal additives, pressed into discs and sintered at 12000C. It has an encapsulated polycrystalline ceramic body; with metal contacts and wire leads.

APPLICATIONS: A varistor acts as a switch. It is usually used for short circuit protection in power strips or lightning bolts "arrestors" on street power poles. It is also used as a "snobbier" in inductive circuits.

 


Related Discussions:- Voltage dependent resistor

Find tension in string, Q. The block of mass M descend with acceleration ...

Q. The block of mass M descend with acceleration a and mass of string is m. find tension in string? Ans: The tension in the string will not be same at all points as the string h

An experiment with force and motion, An experiment with force and motion ...

An experiment with force and motion Tie a spring clothes peg open by placing one winding of thread about the long ends. Place the clothes peg in the centre of a long table and

Evaluate the specific rotation of the solution, 50 gm of an optically activ...

50 gm of an optically active substance is dissolved in 100 ml of water. A plane polarised light, when passing through 30 cm of the solution, suffers a rotation of 390 in it's plane

Curies law, Curie's law (P. Curie) The susceptibility, khi, of an isot...

Curie's law (P. Curie) The susceptibility, khi, of an isotropic paramagnetic substance is associated to its thermodynamic temperature T through the equation khi = C/T

Charges in different elements, in what depends the charge that each materia...

in what depends the charge that each material has? like glass positive; polystyrene negative; and ebonite negative; at the moment of charge a rod of those materials...?

Materiel heat Sinking, Respected Sir, I am only knowing about materia...

Respected Sir, I am only knowing about material name that can be sink heat much longer area, it can be possible or not? if it possible, how to its work to sink.? Please..

Find the ratio of radii of the two wires, Q. Two wires of same material and...

Q. Two wires of same material and same length have resistances 5 and 10 respectively. Find the ratio of radii of the two wires. R = ρl / A = ρl / πr 2  R 1 = ρl / A = ρl

Motion animation, Motion Animation A car along with a non-zero initial ...

Motion Animation A car along with a non-zero initial speed has a constant acceleration whose value could be controlled through the user.

Nuclear decays, Nuclear Decays Uses a proper Monte Carlo engine to simu...

Nuclear Decays Uses a proper Monte Carlo engine to simulate real decays.The decay of 500 atoms of the fictional element Balonium.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd