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 the mean voltage over half a cycle, An alternating voltage is tri...

An alternating voltage is triangular in shape, rising at a constant rate to a maximumof 300V in 8ms and then falling to zero at a constant rate in 4ms. The negative half cycle

Explain how to calculate constant voltage source, Power is to be supplied f...

Power is to be supplied from a source whose resistance is 20 K ? to a load of 100 ?. Would you consider it as a constant voltage source or current source? Explain. Ans. G

Electronics, if you want to amplify input signal of +-20mV amplitude and a ...

if you want to amplify input signal of +-20mV amplitude and a 100 MHz frequency,which parameters of OP-amp play a significant role? what should be the values of the parameters?just

Rusting, Would a nail rust in oil and water or water and oxygen?

Would a nail rust in oil and water or water and oxygen?

What is time, What is time? 1. This is the question that each true sci...

What is time? 1. This is the question that each true scientist dreads to be asked especially in a public setting by extremely inquisitive young learners. We have learned to ca

Compound pendulum, what is compound pendulum drive its time period?

what is compound pendulum drive its time period?

Electronics, define capacitor filter briefly?

define capacitor filter briefly?

Farad, farad; F (after M. Faraday, 1791-1867) The derived SI unit of c...

farad; F (after M. Faraday, 1791-1867) The derived SI unit of capacitance, described as the capacitance into a capacitor that, if charged to 1 C, contain a potential differenc

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