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

Define resistance, The characteristics of substance by virtue of which it o...

The characteristics of substance by virtue of which it opposes the flow of current by it, is called as the resistance.

Light, If the angle of incidence is 60 degrees,then what is the angle of de...

If the angle of incidence is 60 degrees,then what is the angle of deviation?

#Inductance balanced delta connected load, how to you calculate the inducat...

how to you calculate the inducatnce on a balanced delta circuit?

Determine the position of the bubble from the nearest face, A transparent g...

A transparent glass cube, of side 20 cm has a small air bubble. When it is viewed normally from the nearest face it seems to be at 0.05 cm from that face and when it viewed throug

Second law of motion, A 25 N box is pulled vertically upward by means of a ...

A 25 N box is pulled vertically upward by means of a cord.Find the acceleration of the box if the tension in the cord is 35 N.

Explain the photoelectric electricity, Photoelectric electricity is produce...

Photoelectric electricity is produced directly from solar energy when which following are absorbed in a semiconductor to create an electric current? a)  Protons b)  Electron

Explain doppler effect, Whenever there is a relative speed among a source o...

Whenever there is a relative speed among a source of sound and the listener, the apparent frequency of sound listen by the listener is dissimilar from the real frequency of sound e

Determine the minimum pressure, The water level in a tank is 20 m above the...

The water level in a tank is 20 m above the ground. A hose is connected to the bottom of the tank, and the nozzle at the end of the hose is pointed straight up. The tank is at sea

Determine the forbidden gap of silicon, For silicon the forbidden gap is ...

For silicon the forbidden gap is (A) 1.1ev. (B) 0.25ev. (C) 0.5ev. (D) 0.7ev. Ans: For silicon the forbidden gap is 1.1ev.

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