clippers and clamers
TRANSCRIPT
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Diode
Clippers, Clampers
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Diode Clippers
A clipper (or limiter) is a circuit used to eliminate some
portion (or portions) of a waveform.
– A series clipper is in series with its load.
– A shunt clipper is in parallel with its load.
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Series Clippers
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Negative Shunt Clipper Operation
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Biased Shunt Clippers
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Double Diode Clippers
Notice that this circuit contains a shunt positive clipper with positive bias andshunt negative clipper with negative bias.
When the biased voltage reaches +8.7V diode D1 conducts and above thatvolt level no current flow through R L. Hence limit the waveform to 8.7V.Diode D2 does not conduct until the voltage reaches —6.7V and negativevoltage belows —6.7V are clipped off. The resulting output waveform isshown at the output of the circuit.
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Diode Clampers
A clamper (or
dc restorer) sets
(or restores) the
dc reference of a
waveform.
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Biased clampers
Biased clampers allow a waveform to shifted above or
below a dc reference other than 0 V.
– The dc reference is determined by the biasing voltage (V B) and the
setting of the potentiometer (R1).
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Diode :- ClamperPositive Clamper
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Diode :- Clamper
Negative Clamper
During the positive half cyclethe diode conducts and actslike a short circuit. Thecapacitor charges to peak valueof input voltage V m . During this
interval the outputVo
which istaken across the short circuitwill be zero During the negativehalf cycle, the diode is open.The output voltage can befound by applying KVL.
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Diode :- Clamper
Negative Clamper
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Diode :- ClamperBiased Clamper
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Diode :- Clamper
The circuit of a positively biased clamper is shown inthe figure. During the negative half cycle of the input
signal the diode is forward biased and acts like a
short circuit. The capacitor charges to Vi + Vs .
Applying the KVL to the input side
During the positive half cycle of the input signal, the diodeis reverse biased and it acts as an open circuit. Hence V s hasno effect on V o . Applying KVL around the outside loop.