Application of full wave rectifier

Answer 1

Transformer is used to step down the voltage. Your normal supply voltage is 230V but diodes used in rectifier can't handle that huge voltage hence this voltage needs to be reduced. This is done by transformer. Transformer brings down 230V voltage to say 10V. If you are talking about step down transformer than you should know that step down transformer produces equal voltages although opposite in polarity but equal in magnitude(ie +V and -V) across both diodes. If you don't use it the voltage across one diode may be greater than voltage across other diode. Say non-center tapped transformer produces 10V across diode D1 & -8V across diode D2. In next half cycle, -10V will be produced across d1 & +8V across D2. So in first half cycle current due to forward biased diode D1(as voltage across it is greater) will be greater than the current produced due to diode D2 in next half cycle. So rectified current waveform won't be equal.

The transformer is for isolation so the full wave rectifier can float free of the line hot & neutral wires. The power supply can then define its own ground node without "fighting" the line, this is also much safer for the user. Step-up, Step-down, or one-to-one transformer types are irrelevant to full wave rectifier but are selected by the needs of the application. There are solid state diodes that can handle several thousand volts if the application needs it and vacuum tube diodes that can go even higher.

Full wave bridge rectifiers do not use center tapped transformer secondaries, but require the isolation the transformer provides or diodes will blow out in operation!

Answer 2

Full wave rectification is a conversion process. Using the transformer, the input waveform is converted to the opposite at its output, so it is converted to positive or negative.

ADDED: They are two completely separate things even if working together in a particular circuit. The transformer converts to a/c voltage to another; the rectifier then converts the secondary a.c. to d.c.

Answer 3

Rectifiers are used in DC power supplies. A full wave rectifier will convert a sine wave or other wave oscillating between positive and negative to a wave which oscillates between zero and the maximum amplitude. Next the wave goes through a filter circuit which smooths out the signal to a relatively flat line DC.

Answer 4

A: Not essential at all but desirable for the simple fact that it can transform the input voltage to voltage that readily can be useful. Additionally it provide isolation from the source. A bridge rectifier can be applied direct to the line so the transformer is not essential except for the above reasons

Answer 5

a half wave rectifier is used to get a dc voltage .so, when we want to get a dc voltage from ac voltage ,so transformer first transform this voltage to a low ac voltage then rectifier convert it in to dc.

Answer 6

Shouldn't be used.

There are five kinds of rectifiers.

The first is the half-wave rectifier--a single diode. If you want to chop your power by 50 percent, this is what you use--and there are reasons for doing it. If you want to build a dual-brightness lamp, you can put an SPST switch with a diode across it in the circuit. When the switch is closed, the lamp is at full brightness; open the switch and the lamp is at half-brightness. Other than that, these aren't too good.

Next is the full-wave rectifier--two diodes hooked to a center-tapped transformer. These were popular in the vacuum tube era, when we used expensive diode tubes to rectify current. The tubes were expensive, they had to be heated (which took electricity) and you had to deal with ridding yourself of the heat. Now everyone uses solid state rectifiers, so this isn't an issue. The disadvantage of doing business this way is you need a transformer with a secondary voltage twice as high as the working voltage is--if you're trying to get 12v out of the supply, you need a 24v transformer. (Well, actually 30v because you lose voltage in the rectifier diodes, plus a lot of things have regulated power supplies and voltage regulators drop the voltage...) I don't recommend this--right now it's cheaper to build a bridge rectified supply than a full-wave rectified one because the two diodes cost less than what you save by using the smaller transformer. It also runs cooler--bigger Transformers create more heat.

Third is the bridge rectifier. It's made of four diodes. Bridge rectifiers don't need center-tapped transformers, and the voltage on the transformer secondary is about the same as the supply's working voltage. You can buy bridge rectifiers as single components. If you're looking for one voltage--say, 12v--this is the way to go.

Fourth is the "positive/negative full wave rectifier." All the rectifiers above produce either positive voltage or negative voltage depending on which way you put the diodes in. Sometimes you need BOTH positive and negative voltages--the Intel 8080a microprocessor needed +5, -5 and +12v on three separate pins (-5 on pin 11, +5 on pin 20 and +12 on pin 28, with ground on pin 2) to work, and there's a specific sequence they must be turned on. If you need both positive and negative voltages, this gets you there. The output voltage is half the transformer voltage--a 24v transformer makes +12 and -12.

The most fun one is the Cockcroft-Walton Generator. This is a voltage-multiplying rectifier.

Answer 7

To provide full wave rectification, usually as a first step to convert AC power to DC.

Answer 8

to reduce ripple

Answer 9

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