EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Undweeber on April 04, 2018, 12:22:19 am
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What is the difference between rectifier and full bridge rectifier
when i googled full bridge rectifier it had capacitors and such
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The capacitors are almost always used along with a rectifier, but are not part of the rectifier itself.
Rectifier is a generic term. "half wave rectifier" and "full bridge rectifier" are two common designs.
https://en.wikipedia.org/wiki/Rectifier
There's also more advanced/complicated forms of rectifiers that use active components to reduce power wastage, but these are pretty rare except in very high efficiency devices (eg expensive PSUs).
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I made a basic rectifier out of diodes, what type of rectifier is that?
I also scavenged a rectifier chip which is like one inch square flat thing a PC power supply, what type of rectifier is that?
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the one you made depends on how many diodes and how they are connected, the other thing is more than likely a full bridge rectifier.
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A bridge rectifier has four rectifier diodes in a bridge configuration. There is nothing wrong with using four separate rectifiers or two dual rectifiers wired as a bridge.
Note that while a bridge rectifier operates as a full wave rectifier, so can two diodes or a dual rectifier with a center tapped transformer which may be preferable in some applications because the voltage drop will be halved.
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i am pretty sure i made a full bridge rectifier using 4 diodes
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It may help your understanding to realize that half wave and full wave are descriptions of how much of the AC signal is used in the output, while bridge is a circuit arrangement. So when you say full wave bridge you are actually saying two different things about the same circuit.
Half wave means that only one half of the incoming ac signal is transmitted to the output. It may be the positive half or the negative half depending on how you arrange and use the circuit. Full wave means all of the ac signal is used. Since if you just took the positive half and negative half and added them you would end up with nothing there has to be some form of switching or guidance to get the full effect. The bridge configuration of four diodes is one of the most common methods.
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I thing the name FULL bridge rectifier is only used when you use SCR's....a full bridge rectifier is a bridge with only SCR's and not a mix of diodes and SCR's.
For a bridge rectifier with only diodes, no need to name it FULL bridge rectifier.
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I thing the name FULL bridge rectifier is only used when you use SCR's....a full bridge rectifier is a bridge with only SCR's and not a mix of diodes and SCR's.
For a bridge rectifier with only diodes, no need to name it FULL bridge rectifier.
I have never come across such a distinction - but then there's a lot I don't know.
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I thing the name FULL bridge rectifier is only used when you use SCR's....a full bridge rectifier is a bridge with only SCR's and not a mix of diodes and SCR's.
For a bridge rectifier with only diodes, no need to name it FULL bridge rectifier.
"Full bridge rectifier" is short for "Full wave bridge rectifier". It applies to any rectifier that utilizes the full wave. It doesn't matter if it's diodes, SCRs, or actively driven transistors.
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What is the difference between rectifier and full bridge rectifier
Application.
I made a basic rectifier out of diodes, what type of rectifier is that?
4 diodes = bridge
I also scavenged a rectifier chip which is like one inch square flat thing a PC power supply, what type of rectifier is that?
Bridge again.
Study the link that Whales offered as it shows most applications of diode usage for rectification.
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I thing the name FULL bridge rectifier is only used when you use SCR's....a full bridge rectifier is a bridge with only SCR's and not a mix of diodes and SCR's.
For a bridge rectifier with only diodes, no need to name it FULL bridge rectifier.
"Full bridge rectifier" is short for "Full wave bridge rectifier". It applies to any rectifier that utilizes the full wave. It doesn't matter if it's diodes, SCRs, or actively driven transistors.
It seems to me that a bridge rectifier is always a full wave rectifier even if it is used with center tap transformer ....Center tap rectifier with 2 diodes is also a full wave rectifier but it is not a bridge rectifier.
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Okay so the exact 2 rectifier chips that I have are as follows:
GBJ2J - 2.0A GLASS PASSIVATED SINGLE-PHASE BRIDGE RECTIFIER
http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html)
GBU8K - RECTIFIER BRIDGE 8A 800V GBU
https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838 (https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838)
so are these full wave rectifiers? will they be able to turn 21 VAC to DC? what is the lowest voltage they can operate at? would they work well at hand crank speeds or should i rather use 4 diode bridge rectifier? would this type even convert full wave of AC to DC or does it only use half a wave? do the ones i have utilize full wave?
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Okay so the exact 2 rectifier chips that I have are as follows:
GBJ2J - 2.0A GLASS PASSIVATED SINGLE-PHASE BRIDGE RECTIFIER
http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html)
GBU8K - RECTIFIER BRIDGE 8A 800V GBU
https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838 (https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838)
so are these full wave rectifiers? will they be able to turn 21 VAC to DC? what is the lowest voltage they can operate at? would they work well at hand crank speeds or should i rather use 4 diode bridge rectifier? would this type even convert full wave of AC to DC or does it only use half a wave? do the ones i have utilize full wave?
Other than their individual specs, they are both rectifier bridges.
They convert AC to full rectified DC......not pure DC as to get that you must add smoothing caps.
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"Full bridge rectifier" is short for "Full wave bridge rectifier".
OK. That makes sense - but it's not something I've encountered before.
It seems to me that a bridge rectifier is always a full wave rectifier even if it is used with center tap transformer ....Center tap rectifier with 2 diodes is also a full wave rectifier but it is not a bridge rectifier.
Yep.
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I thing the name FULL bridge rectifier is only used when you use SCR's....a full bridge rectifier is a bridge with only SCR's and not a mix of diodes and SCR's.
For a bridge rectifier with only diodes, no need to name it FULL bridge rectifier.
"Full bridge rectifier" is short for "Full wave bridge rectifier". It applies to any rectifier that utilizes the full wave. It doesn't matter if it's diodes, SCRs, or actively driven transistors.
It seems to me that a bridge rectifier is always a full wave rectifier even if it is used with center tap transformer ....Center tap rectifier with 2 diodes is also a full wave rectifier but it is not a bridge rectifier.
Very true. A full wave rectifier only needs two diodes and a transformer, to generated split phase AC. This design was very common, when diodes were expensive.
(http://learning.uonbi.ac.ke/courses/SPH307/scormPackages/path_2/PIC.90.JPG)
Now cheap silicon and Schottky diodes are widely available, a four diode bridge rectifier is more common.
(http://learning.uonbi.ac.ke/courses/SPH307/scormPackages/path_2/PIC.87.JPG)
http://learning.uonbi.ac.ke/courses/SPH307/scormPackages/path_2/43_the_fullwave_rectifier1.html (http://learning.uonbi.ac.ke/courses/SPH307/scormPackages/path_2/43_the_fullwave_rectifier1.html)
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On dual rectifiers with CT transformers: How does one calculate I-max DC after decent smoothing caps?
(since only half of secondary winding conducts on each half-cycle, can useful current yield be increased as a general rule?)
Eg: I have not tested this, but I have 25.2vct @ 2amps. Is end result ~17vdc @ 3amps? (counting single diode drop)
(** This assumption draws 50% more current out of each half winding based on available flux in the core)
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It seems to me that a bridge rectifier is always a full wave rectifier even if it is used with center tap transformer ....Center tap rectifier with 2 diodes is also a full wave rectifier but it is not a bridge rectifier.
It becomes two center tapped full wave rectifiers.
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On dual rectifiers with CT transformers: How does one calculate I-max DC after decent smoothing caps?
(since only half of secondary winding conducts on each half-cycle, can useful current yield be increased as a general rule?)
Eg: I have not tested this, but I have 25.2vct @ 2amps. Is end result ~17vdc @ 3amps? (counting single diode drop)
(** This assumption draws 50% more current out of each half winding based on available flux in the core)
@Undweeber, sorry if that stretched the purpose of your thread..
**edit: Still it's useful to know if the full-wave, dual-rectifier circuit makes reason to up-rate a transformers output on a single-rail supply. (within reasonable limits of secondary winding ampacity :popcorn: )
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Okay so the exact 2 rectifier chips that I have are as follows:
GBJ2J - 2.0A GLASS PASSIVATED SINGLE-PHASE BRIDGE RECTIFIER
http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/184803/WTE/GBJ2J.html)
GBU8K - RECTIFIER BRIDGE 8A 800V GBU
https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838 (https://www.digikey.com/product-detail/en/vishay-semiconductor-diodes-division/GBU8K-E3-45/GBU8K-E3-45GI-ND/604838)
so are these full wave rectifiers? will they be able to turn 21 VAC to DC? what is the lowest voltage they can operate at? would they work well at hand crank speeds or should i rather use 4 diode bridge rectifier? would this type even convert full wave of AC to DC or does it only use half a wave? do the ones i have utilize full wave?
The bottom end of the voltage range is limited by the forward drop of the diodes, the 800V rectifier could have around a 2V drop when you factor in that two diodes will be conducting at a time. Whether you use an integrated bridge or separate diodes makes no difference at all, those bridge rectifier modules contain four diodes inside. If you need a very low voltage drop you could use Schottky diodes.