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The forward converter is a DC/DC converter that uses a transformer to increase or decrease the output voltage (depending on the transformer ratio) and provide galvanic isolation for the load. With multiple output windings, it is possible to provide both higher and lower voltage outputs simultaneously.

While it looks superficially like a flyback converter, it operates in a fundamentally different way, and is generally more energy efficient. A flyback converter stores energy in the magnetic field in the transformer air gap during the time the converter switching element (transistor) is conducting. When the switch turns off, the stored magnetic field collapses and the energy is transferred to the output of the flyback converter as electric current. The flyback converter can be viewed as two inductors sharing a common core with opposite polarity windings.

In contrast, the forward converter (which is based on a transformer with same-polarity windings, higher magnetizing inductance, and no air gap) does not store energy during the conduction time of the switching element — transformers cannot store a significant amount of energy, unlike inductors.^[1] Instead, energy is passed directly to the output of the forward converter by transformer action during the switch conduction phase.

While the output voltage of a flyback converter is theoretically infinite, the maximum output voltage of the forward converter is constrained by the transformer turns ratio $\textstyle N_{\mathrm {S} }/N_{\mathrm {P} }$ :

V_{\mathrm {out} }=D\cdot {\frac {N_{\mathrm {S} }}{N_{\mathrm {P} }}}\cdot V_{\mathrm {supply} }

where $D$ is the pulse width modulator duty cycle.

The forward converter is typically used in off-line supplies to provide an intermediate power output level of 100–200 watts.^[2]

References

^ Anders Lind, IFNA PMM, (v1.0, March 2013) Design Note AN 2013-03. "Single Transistor Forward Converter Design". Infineon Technologies. Archived from a copy on Digikkey on 2015-09-23.
^ Hart, Daniel (2010). Power Electronics. William C Brown Publishing. OCLC 436031173.

External links

Rudy Severns (July 2000). "The History of the Forward Converter" (PDF). Switching Power Magazine. Archived from the original (PDF) on July 18, 2014. Retrieved 5 Sep 2012.

This electronics-related article is a stub. You can help Wikipedia by expanding it.

[1] Anders Lind, IFNA PMM, (v1.0, March 2013) Design Note AN 2013-03. "Single Transistor Forward Converter Design". Infineon Technologies. Archived from a copy on Digikkey on 2015-09-23.

[Hart-2] Hart, Daniel (2010). Power Electronics. William C Brown Publishing. OCLC 436031173.

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+{{Short description|Type of voltage converter circuit}}
-The '''forward converter''' is a [[DC-DC conversion|DC/DC]] converter that uses [[transformer]] windings to buck or boost the voltage ( depending on the transformer ratio ) and provide [[galvanic isolation]] for the load. It performs the same operation as the [[flyback converter]], but is generally more energy efficient.
+[[File:Schematic of a forward converter.png|thumb|400px|A schematic showing the most important components of a forward converter.]]
+[[File:Forward Converter ATX PC Power Supply IMG 1092.jpg|thumb|ATX PC Power Supply with Forward Converter (heat sinks are removed for better view)]]
+The '''forward converter''' is a [[DC-DC conversion|DC/DC]] converter that uses a [[transformer]] to increase or decrease the output voltage (depending on the transformer ratio) and provide [[galvanic isolation]] for the load. With multiple output windings, it is possible to provide both higher and lower voltage outputs simultaneously.
-For comparison, a flyback converter stores energy as a magnetic field in an inductor airgap during the time the converter switching element ( transistor ) is conducting. When the switch turns off, the stored magnetic field collapses and the energy is transferred to the output of the flyback converter as electric current. In contrast the forward converter ( which is based on a transformer ) does not store energy during the conduction time of the switching element - transformers cannot store a significant amount of energy unlike inductors. Instead, energy is passed directly to the output of the forward converter by transformer action during the switch conduction phase.
+While it looks superficially like a [[flyback converter]], it operates in a fundamentally different way, and is generally more energy efficient. A flyback converter stores energy in the magnetic field in the transformer air gap during the time the converter switching element (transistor) is conducting. When the switch turns off, the stored magnetic field collapses and the energy is transferred to the output of the flyback converter as electric current. The flyback converter can be viewed as two inductors sharing a common core with opposite polarity windings.
+In contrast, the forward converter (which is based on a transformer with same-polarity windings, higher magnetizing inductance, and no air gap) does not store energy during the conduction time of the switching element — transformers cannot store a significant amount of energy, unlike inductors.<ref>
-The use of a transformer in the forward converter also constrains the maximum output voltage to the transformer turns ratio, 'n'.
+Anders Lind, IFNA PMM, (v1.0, March 2013)
+Design Note AN 2013-03. "Single Transistor Forward Converter Design". [[Infineon Technologies]].
-The transfer function is:
+Archived from [https://web.archive.org/web/20150923214730/http://www.digikey.com/web%20export/supplier%20content/Infineon_448/mkt/coolMOS/SingleXTRForward.pdf a copy on Digikkey] on 2015-09-23.
-<br>
+</ref> Instead, energy is passed directly to the output of the forward converter by transformer action during the switch conduction phase.
-:<math>\frac{V_{out}}{V_{supply}}=\frac{D}{n}</math><br>
-where 'D' is the [[pulse width modulator]] duty cycle and 'n' is the transformer turns ratio, <math>\frac{N_p}{N_s}</math>
+While the output voltage of a flyback converter is theoretically infinite, the maximum output voltage of the forward converter is constrained by the transformer turns ratio <math>\textstyle N_\mathrm{S}/N_\mathrm{P}</math>:
-The forward converter is used to provide a higher power output (100&ndash;200 [[watt]]s).<ref name="Hart">{{cite book|title=Power Electronics|last=Hart|first=Daniel|publisher=William C Brown Publishing|url=http://www.worldcat.org/oclc/436031173&referer=brief_results|year=2010}}</ref><ref name="NPTEL">{{cite web|url=http://nptel.iitm.ac.in/courses/Webcourse-contents/IIT%20Kharagpur/Power%20Electronics/PDF/L-23%28DP%29%28PE%29%20%28%28EE%29NPTEL%29.pdf|title=Power Electronics|work=National Programme on Technology Enhanced Learning|accessdate=November 20, 2009}}</ref>
+:<math>V_\mathrm{out}=D\cdot\frac{N_\mathrm{S}}{N_\mathrm{P}}\cdot V_\mathrm{supply}</math>
+where <math>D</math> is the [[pulse width modulator]] duty cycle.
+The forward converter is typically used in [[Off line regulator|off-line supplies]] to provide an intermediate power output level of 100&ndash;200 [[watt]]s.<ref name="Hart">{{cite book|title=Power Electronics|last=Hart|first=Daniel|publisher=William C Brown Publishing|year=2010|oclc=436031173}}</ref>
 ==References==
 {{reflist}}
+==External links==
-{{Electronics-stub}}
+{{Cite web|title=The History of the Forward Converter |author=Rudy Severns |work=Switching Power Magazine |date=July 2000 |accessdate=5 Sep 2012 |url=http://www.dianyuan.com/blog/u/61/1200139220.pdf |url-status=dead |archiveurl=https://web.archive.org/web/20140718093845/http://www.dianyuan.com/blog/u/61/1200139220.pdf |archivedate=July 18, 2014 }}
+{{Commons category|Forward converters}}
-[[de:Eintaktflusswandler]]
+[[Category:DC-to-DC converters]]
+{{Electronics-stub}}