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

Is it is possible to have charge of 7.2*10^-19 c?, No;(Personal Note:Please...

No;(Personal Note:Please Rate this and let me know if this helps) Reason: From the quantisation of charge charactersistic, we can say that charge comes in integral multiple of e (

Spring force, just after cutting of spring will extension becomes zero or n...

just after cutting of spring will extension becomes zero or not

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 their wavelengths, A hydrogen atom is in the ground state. It abso...

A hydrogen atom is in the ground state. It absorbs energy and makes a transition to the  n  = 3excited state. The atom returns to the ground state by emitting two photons. What are

State moseleys law, Q. State Moseley's law. The frequency of the spectr...

Q. State Moseley's law. The frequency of the spectral line in the qualities X-ray spectrum is directly proportional to the square of the atomic number (Z) of the element consid

Amplitude of the resultant wave function, Two travelling sinusoidal waves a...

Two travelling sinusoidal waves are described by the wave functions Y1 = 55.00 sin[π(4.00x - 1200t)] Y2 =55.00 sin[π(4.00x - 1200t - 0.250)] where x, Y1 , and Y2 are in meter

Vernier calliper , measurement and calculation with formula

measurement and calculation with formula

Condesed matter, sodium metal with a body centred cubic structure has two a...

sodium metal with a body centred cubic structure has two atoms per unit cell. the radius of sodium atom is 1.85 å. calculate its electrical resistivity at 0 oc, if the classical va

What locations on the sticks to make it balanced, Here's what is given: A....

Here's what is given: A. There are three 1 meter sticks B. There are four weights: Weight #1 = 1kg Weight #2 = 1.2kg Weight #3 = 1.5kg Weight #4 = 2kg The sticks don't hav

Experiments based on screw gauge, Screw gauge works on the rule of screw. ...

Screw gauge works on the rule of screw. It has a linear scale called as the main scale, and another scale called as the circular scale. The circular scale can be moved by a head sc

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