Protection of Electrical Appliances

8/7/2019 Protection of Electrical Appliances

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PROJECT MEMBERS:

A.ALEXRAJ

S.ANISHKUMAR


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` Sudden fluctuation in supply is a very big problem in industries

anddomestic applications.

` It causes a major loss for industries, offices and homes.

` This project gives a low cost and powerful solution for this problem.

`

` This Circuit protects refrigerators ACs, Microwave ovens as well as

other appliances fromover and under voltage fluctuations.

` Bridge type full wave rectifier is used to rectify the ac

` out put of secondary of 230/12V step down transformer.


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x CAPACITOR

x DIODE

x RELAY

x TRANSFORMER

x SWITCHx 60WATTS ELECTRICAL BULP


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The most common function of a diode is to allow an

electric current to pass in one direction while blockingcurrent in the opposite direction.

This unidirectional behavior is called rectification, and is

used to convert alternating current to direct current, and to

extract modulation from radio signals in radio receivers.

This is due to their complex non-linearelectrical

characteristics, which can be tailored by varying the

construction of theirP-N junction.

These are exploited in special purpose diodes that

perform many different functions. For example,

specialized diodes are used to regulate voltage (Zenerdiodes), to electronically tune radio and TV receivers

(varactor diodes), to generate radio

frequencyoscillations (tunnel diodes), and to produce light.


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A transformeris a static device that

transfers electrical energy from

one circuit to another through inductively

coupled conductorsthe transformer's

coils.

A varying current in the first

orprimarywinding creates a

varying magnetic flux in the transformer's

core and thus a varying magnetic

field through thesecondarywinding.

This varying magnetic field induces a

varying electromotive force (EMF) or

"voltage" in the secondary winding. Thiseffect is called mutual induction.


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A relay is an electrically operated switchh.Many relays use an electromagnet to

operate a switching mechanism

mechanically, but other operating principles

are also used.

Relays are used where it is necessary to

control a circuit by a low-power signal (withcomplete electrical isolation between

control and controlled circuits), or where

several circuits must be controlled by one

signal.

The first relays were used in long distance

telegraph circuits, repeating the signalcoming in from one circuit and re-

transmitting it to another.


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Capacitors store electric charge. They are used with resistors in

timing circuits because it takes time for a capacitor to fill with

charge.

They are used to smooth varying DC supplies by acting as a

reservoir of charge. They are also used in filter circuits because

capacitors easily pass AC (changing) signals but they block DC

(constant) signals.

Inside the capacitor, the terminals connect to two metal plates

separated by a non-conducting substance, or dielectric.

We can easily make a capacitor from two pieces of aluminum foil

and a piece of paper. It won't be a particularly good capacitor in

terms of its storage capacity, but it will work.


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` HIGHLY SENSITIVE.

` LOW COST.

` RELIABLE CIRCUIT.

` EASY TO CONSTRUCT.


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` INDUSTRIAL MACHINERY.

` HOUSE HPLD ITEMS LIKE

TV,REFRIGERATOR,ETC,

` WATER PUMPS.


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Protection of Electrical Appliances

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