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precision rectifier

PRIYADHARSHINI

Feb 6, 2014
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what is the purpose of using precision rectifier in ADC to convert ac to DC? insteaD OF PRECISION RECTIFIER we can use normal rectifier to convert ac to Dc.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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What is the difference between a "rectifier" and a "precision rectifier"? And therein lies the explanation.
 

PRIYADHARSHINI

Feb 6, 2014
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rectifier circuit we use a DioDe for rectification.anD in precision rectifier we use a opamp with DioDes.anD precision rectifier which has a fast forwarD voltagee Drop such that it can conDuct before 0.7v.i posteD WHAT I HAD KNOWN.
 

(*steve*)

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A precision rectifier has zero voltage drop
 

PRIYADHARSHINI

Feb 6, 2014
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k.but in my circuit i useD a precision rectifier.but it proDuce the output with reDuceD negative voltage.
 
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PRIYADHARSHINI

Feb 6, 2014
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k.but in my circuit the precision rectifier gives the output with reDuceD negative voltage.what is the reason for this?
 

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Harald Kapp

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This is not a good circuit for a precision full wave rectifier.
For positive input voltages the output follows V1 via the bypass resistor R1. Any load on the output will reduce the output voltage.
For negative input voltages the rectifier via U1 is active with a gain of 2 (R3(R2). Settting R3=R2 sets gain=1. Then the output is much more symmetrical, but not identical in both half waves if you add a load. Without load it is nearly ideal.


Look here for a discussion of the different types of active rectifier.
 
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