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

Examples, Example of like and unlike parallel forces

Example of like and unlike parallel forces

Explain kelvin-planck statement and clausius statement, Explain Kelvin-Plan...

Explain Kelvin-Planck statement and Clausius statement Kelvin-Planck statement: "No process is possible whose sole result is the absorption of heat from a reservoir and the t

Show how devaluation affects an economy, Q. Using a figure, show how devalu...

Q. Using a figure, show how devaluation affects an economy. Answer: While a currency is devalued from E 0 to E 1  the stability shifts from point 1 to 2. Both money supply and

What is the basic difference between current and voltage, They are exactly ...

They are exactly analogous to water pressure and water flow by a hose. That's why flowing electrons is known as a current, just like a water current. Voltage is the electromotiv

Determine state of calcium atom, Ca has atomic no. 20 and atomic weight 40....

Ca has atomic no. 20 and atomic weight 40. Which of the following statements is not correct about Ca atom: (1)The number of electrons is same as the number of neutrons   (2)

Boltzmann constant, Boltzmann constant; k (L. Boltzmann) This is a cons...

Boltzmann constant; k (L. Boltzmann) This is a constant that describes the relationship among temperature & kinetic energy for molecules in an ideal gas. This is equal to 1.380

Emf of cell, The potential difference across the terminals of a cell when i...

The potential difference across the terminals of a cell when it is not supplying any current is known as it's emf.

Michelson interferometer, describe the construction and working of michelso...

describe the construction and working of michelson''s interferometer explain the formation of circular fringes how will you use these fringis in the determination of difference in

Truth operation by OR GATE, i am class 12 student given an assignment on ''...

i am class 12 student given an assignment on ''to study the truth operation performed by OR GATE.'' please help me with the assignment

What happens to the voltage across resistor, A seat of EMF is in sequence w...

A seat of EMF is in sequence with a resistor R1 and with a parallel combination of two other resistors R2 and R3. R2 is a changeable resistor whose resistance can be changed just b

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