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

Determine phase of vibration of two vibrating particles, Two vibrating part...

Two vibrating particles that are "out of phase" differ in the phase of their vibration by: a) 1/4 cycle b) 1/2 cycle c) 3/4 cycle d) 1 cycle Ans: Two vibra

Infra-red detectors, Part A) Infra-Red (IR) Detectors: An IR detector...

Part A) Infra-Red (IR) Detectors: An IR detector has an impedance of Z= (400+j200) ? . . During design tests the detector current is measured as 4 µA. What is

Isochoric process of thermodynamic, A thermodynamic process, in which the v...

A thermodynamic process, in which the volume of gas always same is known as isochoric process. In this process, the work completed by the body is zero. Therefore from first law

Sphere moves up, A sphere of radius R touches two adjacent sides of a room....

A sphere of radius R touches two adjacent sides of a room.It also touches an inclined plane at a height of R/5 from the floor.the inclined plane moves towards the sphere at the spe

Define the introduction about schrödinger’s atom, Define the introduction a...

Define the introduction about Schrödinger’s Atom. Introduction to the Schrödinger’s Atom: To describe the spectral line puzzle, Bohr came up along with a radical model of t

Continuous emission spectrum, (i) It has of continuously varying wavelength...

(i) It has of continuously varying wavelengths in a exact wavelength range. (ii) It is given by solids, liquids and highly compressed gases heated to high temperature. (iii)

Evaluate the potential energy of the ball, A ball with a mass of 25 grams i...

A ball with a mass of 25 grams is dropped from ledge 908 meters above the ground. What is its kinetic energy the instant before it hits the ground? What is the potential energy of

Explain simple pendulum, Explain Simple Pendulum Simple Pendulum : The...

Explain Simple Pendulum Simple Pendulum : The A point mass suspended by a weight less and inextensible string to a friction less support is known as a Simple pendulum.

Wiedemann-franz law, Wiedemann-Franz law: The ratio of thermal conduct...

Wiedemann-Franz law: The ratio of thermal conductivity of a particular pure metal to its electrical conductivity is approximately constant for any given temperature. This law

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