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

#title.the number of pixels related to the actual phase, #question.i want t...

#question.i want to know the number of pixels related to the actual phase value in an image and want to separate the zero phase valued pixels from the image.

The quantum no having non integral value, the quantum no having non integra...

the quantum no having non integral value is ? what does it designate

How radar gun measuring the velocity, When a radar gun says the pitch is 90...

When a radar gun says the pitch is 90 miles per hour at what point in the balls travel to home plate is the radar gun measuring the velocity? The measurement is made at the po

Determine element that atomic weight is double atomic number, The atomic we...

The atomic weight of an element is double its atomic number. If there are four electrons in 2P  orbital, the element is : (1) C                       (2) N       (3) O

Calculate the local value of g, An astronaut on a small planet wishes to me...

An astronaut on a small planet wishes to measure the local value of  g  by timing pulses traveling down a wire which hasa large object suspended from it. Assume a wire of mass3.50

Current electricity, Why do magnetic field lines contract longitudinally an...

Why do magnetic field lines contract longitudinally and exert a lateral pressure?

Explain about electric field, Explain about Electric Field Electric Fie...

Explain about Electric Field Electric Field:  Field formed by a single or group of charges that permeates all space.  Fields are responsible for making forces at a distance

What is illumination, What is Illumination? A body that gives off light...

What is Illumination? A body that gives off light is called luminous, like all those glow-in-the-dark toys, and a body that gives off light when it is heated is called incandes

Magnetism, when a soft iron piece is buried under the surface of earth in t...

when a soft iron piece is buried under the surface of earth in the north south direction why the iron piece show properties of a magnet

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