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Why is precision rectifier called this way?

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sayurabh

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why precision rectifier is called precision rectifier?it is made by using opamp but it dosimply rectifiacion just like by using transformer but why it is called precision rectifier both are doing same work
 

the_edge

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Re: precision rectifrier

Actualy with transformer you dont get good output voltage, cause diodes on output your input voltage must rise enough to drive those diodes... That is not case with opamp, because as soon as input voltage is positive you have output voltage that is just amped input voltage....
 

cesare

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Re: precision rectifrier

A normal rectifier add a 0.6V drop. The feedback loop in the precision rectifier avoid this drop.
 

Meridian

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Re: precision rectifrier

sayurabh said:
why precision rectifier is called precision rectifier?it is made by using opamp but it dosimply rectifiacion just like by using transformer but why it is called precision rectifier both are doing same work

Add to the answers of 'Cesare':

A precision amplifier has very low drift due to temperature fluctuations or tolerance specs of the device itself. This makes them very stable.

Secondly, you can't just compare an AC transformer with semiconductor device. There is just no comparison. It's like comparing whipcream with mayonaise... :D
 

Kral

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Re: precision rectifrier

sayurabh,
A precision rectifier typically has the diode(s) inside the feedback loop. This means that the diode forward drop is essentially reduced by a factor equal to the loop gain.
Regards,
Kral
 

The Joy of Electronics

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Re: precision rectifrier

First of all With Transformers U step up or Step Down the voltage not rectify it! Secondly, in regular Rectifiers, as was mentioned, some voltage drops across the rectifying diodes.
 

Vabzter

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Re: precision rectifrier

To rectify signals less that 0.6V like signals from a sensor e.t.c which may be in mV. A normal rectifier like bridge will not work as the signal is less than threhold of the diodes.
 

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