Design a push-pull converter

[jessper]

Hi,
I walk a while with an idea to build a power supply for an audio power amp.
I have search on the web for an ac/dc converter, 230Vac in, and 2x 56-63Vdc out. With a power of 350-400W.
If such a converter exist, it will be very expensive.

So, with this short explanation, can we here design a push-pull converter on such way, that finally everybody with understanding can build this converter, without (much/ big)problems?
Please, give me your opinion !

 

[Easyamp]

You are asking a lot with that simple question. Working with ac mains is very dngerous even for experienced, electrically inclined Individuals, only takes one oops sometimes. With that said, there are many push pull schematics available that would require only minor tweaking to get your specific requirements.
I feel it would be very difficult to create a project of this nature that would be easy or give no big problems without knowing who will attemp it or there level experience.

 

[jessper]

Hi Easyamp,

I fully agree that working with mains ac (electric power)is dangerous. But this is not a reason to not working with the mains.
On this site I saw that after rectifier the mains a voltage devider is used. This can be a possibility for the discussion. To discuss a
pp converter will discover some difficulties, and I believe a lot of people like to know that. I too.
If possible, can you print here a few pp circuits?

Any thoughs, opinion or whatelse are welcome !

 

[Easyamp]

I agree also, that it is not a reason to try, and too always be careful. But that is my internal advice for myself, as I try not to persuade or others
to get in there and start fiddling. If you know what you are doing then you know who you are.

I was thinking about your idea for a push pull supply at 230vac and wondered if you would rather try a half bridge instead.
The primary switching mosfets are going to see double the primary switching voltage, which is already 330vdc. You will need
700+ volt fets and that's with no overshoot or ringing, probably be safer with 800+ volt fets. Half/full bridges can be a little more
complex, but isn't that half the fun. Let me know if you want to try a half or full bridge as this is currently what I'm playing with.

If not I will dig up some designs for low voltage push pulls as this is all I have. They are for automotive audio amplifiers and run
from 12 or 24v and put out 40v or 50v or however many turns you put on the secondary. They are all unregulated as I never
saw the need to regulate for an audio amplifier.

 

[Silvio]

Hello Jessper, As Easyamp said it is not a strait forward job to build an SMPS especially if it is an off grid one. The reason for this is that now you are fiddling with high voltages that might kill you if you do not take necessary precautions. There are warnings that you should read before starting something. There are also blog posts that you can read and download files to guide you in the right direction. Knowing all this one can make a simple un-regulated SMPS without many surprises. Off line SMPS do not joke when they blow and care must be taken at all times. SMPS is not for beginners and some knowledge in electronics is essential. An oscilloscope is also needed as you will not see what is going on.

Please follow the instructions given so that you will know better what to do and not do.

Regards, Silvio