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

SAFA, Physics assignment electron microscopy component, solve problem. can ...

Physics assignment electron microscopy component, solve problem. can u solve these two problems with detailing and referencing if it needed

Thermoelectric power:, The rate of modification of thermo emf with the chan...

The rate of modification of thermo emf with the change in the temperature of the hot junction is known as thermoelectric power.

Two simple harmonic motions have the same periodic time, When the two simpl...

When the two simple harmonic motions have the same periodic time but different amplitude and a phase dissimilarity = ∏/2: The resultant curve may be attained graphically as abov

A 35-kg child is riding on a swing that rises to a maximum h, Neglecting fr...

Neglecting friction, what is the child''s gravitational potential energy at the top of the swing? What is the child''s kinetic energy at the top of the swing?

Cyclotron, what does it do?function?

what does it do?function?

Write any four characteristics of electromagnetic waves, Write any four cha...

Write any four characteristics of electromagnetic waves. Give two uses each of 1. Radio-waves 2. Micro-waves.

Determine the velocity of an object, An impulse of 10 kilogram-meters per s...

An impulse of 10 kilogram-meters per second acting on an object whose mass is 5 kilogram will cause a change in the objects velocity of: a) 0.5 meters per second b) 2 met

Vectors, What is the best means of solving a vector problem? By using 2 or ...

What is the best means of solving a vector problem? By using 2 or 3 Cartesian coordinates?

Explain the concept of net force, Muturi is rearranging some furniture. ...

Muturi is rearranging some furniture. He pushes the dresser with a force of 143 N,and there is opposing frictional force of 112 N. What is the net force ?

Simple harmonic motion ii, Simple Harmonic Motion II In physics, simple...

Simple Harmonic Motion II In physics, simple harmonic motion is a type of periodic motion where the restoring force is directly proportional to the displacement. It can serve a

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