12V push pull SMPS

[EWorkshop1708]

Hi

Best I can buy without ordering them anywhere, Irfz44n's...Yes, yes I know

Hey, if that's what you got, then use em! As long as they do the job, not everyone is gonna get the biggest MOSFETS, they are not always available.

How many of those Irfz44n do you plan to use to get 1KW? Is much heatsinking required for 1KW with those?

 

[Boris_The_Blade]

What are some good sources for Toroid Cores???

I've bought from www.cwsbytemark.com before. They have a decent selection of iron power, MPP, HF, ferrite, etc for decent prices at low quantities, but their website is kind of a mess.

 

[luka]

Hey, if that's what you got, then use em! As long as they do the job, not everyone is gonna get the biggest MOSFETS, they are not always available.

How many of those Irfz44n do you plan to use to get 1KW? Is much heatsinking required for 1KW with those?

To start with I have 2 per side, and PCB was made to hold up to 6 per side. How much heatsink? I hope that what I have will be overkill since this should be very high efficient supply, I will just have to see. Tomorrow comes winding trafo day again...I can already fill pain in my fingers

 

[EWorkshop1708]

I've bought from www.cwsbytemark.com before. They have a decent selection of iron power, MPP, HF, ferrite, etc for decent prices at low quantities, but their website is kind of a mess.

Thanks.

I noticed they sell 4 and 5 inch toroids. I wonder if you can get 2KW from a 5 inch wound with (4 x 12 gauge) coil wire on primary using push-pull......

 

[EWorkshop1708]

To start with I have 2 per side, and PCB was made to hold up to 6 per side. How much heatsink? I hope that what I have will be overkill since this should be very high efficient supply, I will just have to see. Tomorrow comes winding trafo day again...I can already fill pain in my fingers

Winding Toroids are a pain in the @$$!

I'm glad as least with SMPS it's a lower number of turns, and it's not like 100 or more But thick wire is hard to wind, and makes sore fingers!

 

[N-Channel]

Yeah, but in the end, IT LOOKS COOL!

 

[Boris_The_Blade]

Thanks.

I noticed they sell 4 and 5 inch toroids. I wonder if you can get 2KW from a 5 inch wound with (4 x 12 gauge) coil wire on primary using push-pull......

Winding Toroids are a pain in the @$$!

I'm glad as least with SMPS it's a lower number of turns, and it's not like 100 or more But thick wire is hard to wind, and makes sore fingers!

Use many more strands of finer wire. I use a cordless drill to twist enameled wire to make my own semi-litz wire. Much easier on the hands

 

[luka]

Hi Boris_The_Blade

Cross section is cross section, do you know how many smaller wires I would need to use...say for 12x 1mm for each primary... litz is good for offline supplys

 

[adi109cj]

I see a push-pull schematic on this web page:http://www.trifolium.de/netzteil/kap8.html

schematic: http://www.trifolium.de/netzteil/img/kap8_3b.gif
It has auxiliary winding for energy recovery !?
what is the purpose of that auxiliary winding ?
The text is in german language.
The google translation is not very accurate.

thanks

 

[Eva]

This is a clever circuit, the auxiliary windings, the capacitors and the diodes are used to recover the energy stored in transformer leakage inductance.

 

[areza]

googling comes up with this 20yrs old patent US4706181 , showing an extra coupled inductor also recovery energy, may be a good way to save some energy if it’s a kw thing for some extra effort , but i m gonna use it in my 300w dc-dc conv , cos i need to save energy in every possible way, thank you all

 

[adi109cj]

push-pull trafo windings arrangement

what is the best windings arrangement for an push-pull trafo wind on a EE ,EI or ETD core ?
First primary windings and secondary over it ?
or whith split primary or secondary ?
to obtain best coupling between primary and secondary windings and minimum leakage inductance.

thanks