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

Mean life, WE are estimating the spares requirement for a radar power suppl...

WE are estimating the spares requirement for a radar power supply. The power supply was designated with a mean life of 6500 hours. the standard deviation determined from testing is

Two vibrating body , Will there be any change in hz of sound if two vibrati...

Will there be any change in hz of sound if two vibrating body has the similar hz Ans) Yes it depends on the path difference among them... Like in destructive inteference u

Concept of force and newton''s laws, FORCE AND NEWTON'S LAWS   1.   ...

FORCE AND NEWTON'S LAWS   1.   Ancient view objects tend to stop if they are in motion; force is needed to keep something motion. This was a natural thing to believe in beca

What are the favorable conditions for formation of cat ions, There are seve...

There are several conditions for formation of cat ions ? Low Ionisational potential ? Lesser Charge ? More atomic size of atoms forms cations easily ? Ions having Inert

What is the circumference of the ball, Suppose a baseball rolls 3.2 m acros...

Suppose a baseball rolls 3.2 m across the floor. If the ball's angular displacement is 82 rad, what is the circumference of the ball?

Explain centrifugal force, Feeling centrifugal force Tie a weight to a...

Feeling centrifugal force Tie a weight to a string about a metre in length and then whirl the weight around at arm's length. View the outward pull on the string. This is centri

What are the safety terms to be inspected on battery, What are the safety t...

What are the safety terms to be inspected on battery? Ans: Safety terms to be checked on battery are full complements of battery box fixing bolts and its tightness, observat

Youngs experiment, Young's experiment; double-slit experiment (T. Young; 18...

Young's experiment; double-slit experiment (T. Young; 1801): A popular experiment which illustrates the wave nature of light (and indeed of other particles). Light is passed f

De broglies wavelength-nature of light, An electron is in a box of width 3*...

An electron is in a box of width 3*10^-10m.what are de broglies wavelength and magnitude of momentum of the electron if it is in A)n=1 level B)n=2 level C)n=3 level Ans)  Use the

Determine the object direction, Q. If the net force acting on an object is ...

Q. If the net force acting on an object is in the positive x-direction, the object moves only in the positive x-direction. It is not true, the object will accelerate only in the

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