Design of isolated buck converter

[AshwinNambiar]

I would like help in the design of an isolated buck converter.The input voltage varies from 16volts to 32 volts,which makes it a variable DC,at the output i requite a voltage of 18 volts.The d dc converter be designed for an output power of 180 watt.I want to design an isolated buck with the above mentioned specifications using discrete components.Will be glad if could recieve help as to how to go about.I will be both implementing it real time and simulate using either MATLAB or NI MULTISIM.Please help!

 

[Gryd3]

I would like help in the design of an isolated buck converter.The input voltage varies from 16volts to 32 volts,which makes it a variable DC,at the output i requite a voltage of 18 volts.The d dc converter be designed for an output power of 180 watt.I want to design an isolated buck with the above mentioned specifications using discrete components.Will be glad if could recieve help as to how to go about.I will be both implementing it real time and simulate using either MATLAB or NI MULTISIM.Please help!

Use a transformer. There is your isolation
The transformer can be 1:1 or any ratio you want as long as the filtered output voltage is still high enough to operate the buck converter, and that the power handling of the transformer is high enough for your load.

 

[TedA]

I believe that by definition, a buck converter provides no galvanic isolation. To get your isolation, another topology must be chosen. As soon as a transformer is introduced, it's no longer a buck converter.

The problem is that in a buck converter, part of the output current is provided directly from the input supply, so the input and output must have a common return.

At 180W, I would suggest a push-pull forward converter topology, although single ended, and flyback topologies, might be used.

Is this something that will produced in quantity? Or is just one required? Or will the design not get beyond simulation?

Is cost a consideration? Should the parts be mostly from the junkbox?

And are integrated circuits allowed in this design? One can do it with a bunch of transistors, but that's more work.

You might share such information as you have about how much isolation is required, how well the output is to be regulated, how much ripple is allowed on the input and output, and if there are size or other mechanical restraints.

Ted

 

[AnalogKid]

What are the isolation requirements? Does this circuit need to pass safety certs? Also, is there a reason to go through a design process when many power supply manufacturers make a suitable device?

ak

 

[AjayGap]

I hope this link will help in matlab simulation...
http://www.electrical-circuits.com/2016/01/design-of-buck-converter-using-matlab.html

 

[Arouse1973]

The first question is how does a buck conveter work with an input of 16 Volts min when you want an output of 18 Volts?

 

[BobK]

And the answer, is "not very well."

Bob