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

How are the colloids classified on the basis of the nature, How are the col...

How are the colloids classified on the basis of the nature of interaction among dispersed phase and dispersion medium? Describe a significant characteristic of each class. Which of

A sodium cation has different number of electrons from, A sodium cation has...

A sodium cation has different number of electrons from: (1) O 2-                  (2) F -       (3) Li +                    (4) Al +3 Ans: Li +

Vector addition -the order does not matter, Vector Addition The Order Does ...

Vector Addition The Order Does NOT Matter The question frequent arises as to the significance of the order in that the vectors are added. For example, if five vectors are added

Describe the properties of x-rays, (i)  X-rays are electromagnetic waves wi...

(i)  X-rays are electromagnetic waves with wavelength lie among 0.1Å - 100Å. (ii)  X-rays is invisible. (iii) They always go in a straight line with speed of light. (iv) X

Centrifugal force with a tin can lid, Centrifugal force with a tin can lid ...

Centrifugal force with a tin can lid Punch a hole near the edge of a tin can lid. Attach it to the cord from the drill and view the effects of rotation.

Policy management of economic recovery, When the economy experiences a down...

When the economy experiences a downfall, the government knows exactly which policies will spur an economic recovery. Often policymakers fail to take the right decisions for both

Two-or-three-dimensional-motion, Net force acting on particle of mass 2 kg ...

Net force acting on particle of mass 2 kg is 10N in north direction.At t=o, particle was moving eastwards with 10m/s. Find displacement and velocity of particle after 2 seconds.

Newtons rings, Ask question how to write newtons rings in c programming #Mi...

Ask question how to write newtons rings in c programming #Minimum 100 words accepted#

Brownian motion, Brownian motion (R. Brown; 1827) It is the continuous...

Brownian motion (R. Brown; 1827) It is the continuous random motion of solid microscopic particles while suspended in a fluid medium because of the consequence of ongoing bomb

Unit vectors, Unit Vectors A unit vector is a vector of unit length. A...

Unit Vectors A unit vector is a vector of unit length. A easy animation of unit vectors and vector addition. A unit vector is a vector of length 1, sometimes also called a dir

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