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

Motion in one dimension, #question.A tortoise can run with a speed of 0.12 ...

#question.A tortoise can run with a speed of 0.12 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 4.0 minutes.

What are newton s laws of motion, What are Newton s laws of motion? 1. ...

What are Newton s laws of motion? 1. A body at rest will stay at rest and one in motion will stay in motion, unless and unless acted upon by an external force. (Law of inertia)

Manganin is an alloy of which materials, Manganin is an alloy of (A) C...

Manganin is an alloy of (A) Copper, manganese and nickel. (B) Copper and manganese. (C) Manganese and nickel.               (D) Manganese, aluminium and nickel. Ans:

Historical development of atomic models, Historical development of atomic m...

Historical development of atomic models In olden days there was an idea that all matter is made of tiny indivisible particles. When Thomson discovered electron, this idea

Acceleration due to gravity, Who was the first person to show that all obj...

Who was the first person to show that all objects fall toward Earth with constant _________.

Inertia in a pile of books, Inertia in a pile of books Stack up a pile ...

Inertia in a pile of books Stack up a pile of books. Grasp hold of the single at the bottom of the pile and give it a quick jerk. Can you delete it without upsetting the whole

Volume observed by an observer stationed on the earth, A cube of side ‘a' i...

A cube of side ‘a' is moving with speed 0.6 c normal to one of its face. What is its volume observed by an observer stationed on the earth ? The volume of cube = a x a x a = a 3

Radial acceleration..., So I have a question here and I am totally lost: A ...

So I have a question here and I am totally lost: A car starts from rest and accelerates at a constant rate of 1.1 m/s2. If the radius of the car wheels is 29.0 cm, and the final an

Electricity and magnetism, two free charges +q and +5q are a distance L apa...

two free charges +q and +5q are a distance L apart. A third charge is placed so that the entire system is in equilibrium.find the location and magnitude and sign of the charge.

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