300W SMPS for amp. from PC PSU

[Acca]

@mayster
Reverse current or voltage feedback

@psychosatic
Yes,of course

@panos1
No,it must be toroid with high permeabilty like in CFL lamp or similar...
You can try ee16 from psu,it's used as BDT in PC PSU.Only you should add small gap in core,no need for rewounding.

 

[Acca]

Perhaps inverting the feedback winding ?
Also I wonder ,are C1 and C2 polarised in the right direction.The diodes in parallel block the voltage in the direction the electrolytics can handle.
Mona

C1 and C2 is ok.they have about 1,4V on himself

 

[panos1]

ok acca thank you....
may i ask you somehting else..
how can i parallel 2 or 3 transorfers in order to get higher power?
i need about 1kw...

 

[Acca]

Yes,but you should use only one diode in base instead of two

 

[panos1]

acca please can you tell me why i cant rewind and use eel19 core?
and something else..
do you have pcb of the smps? 😉

 

[Acca]

Because it should be high permeability one.You can use original E16/E19 but you must add small gap.If you don't add it,transformer go to saturation and whole inverter works on ~10kHz which is small.
Yes I have pcb,but I don't know where is it.
I'll search now...

 

[Acca]

I find PCB:

 

[panos1]

ok thank oyu..
i am builting it now and when i finish i will post pics...

 

[Acca]

On pcb there is 22R in series with base diode.Short them with small wire,22R isn't needed,better work with short.There's 2k7 in bases too.Remove it,it's not needed,better work without it 🙂

 

[panos1]

ok..
i will built it ''pin to pin'' first and if it works ok i wik modify the pcb in order to fit my needs..
i want to conect 3-4 trnsformers in parallel...
i will conect primaries in parallel and secondaries in series....

 

[Acca]

OK
Now I make much better SMPS,if you can wait,you can use it.I have power IGBT and tested up to 3kW.
And tested to 1200W with 4xE33
But you can make both SMPS 🙂

 

[panos1]

i dont have the required experince to play with igbt..
it's a bit dificult for me..
igbt are expensive too...
so for start i will make this simlpe and very low cost smps...😉

 

[Acca]

😉

IGBT and fets can be used 🙂
And BJT too,with small corection 🙂
But let make this smps first 😉

 

[Acca]

I like low cost smps 😀
And because of this I made amplifier in class D directly connected to mains 😀

 

[panos1]

I like low cost smps 😀
And because of this I made amplifier in class D directly connected to mains 😀

what???????😱
i want to see this monster...😎

 

[Acca]

I'll attach later pics and video.But schematic will not posted for safety reasons 🙂
Maybe I'll post topic on diyaudio,but without schematic 😀

 

[Acca]

This is used for bass speaker in enclosure 🙂
It put about 90-100VAC in speaker 😀

 

[panos1]

how many wats does it put out?
if toy rectify 230 volt you have 330 vdc...
this is about 12kw of power at 4ohm load...
what the hell are you driving with this amp?😀

 

[Acca]

No,no,not 12kW 🙂
First it split to +/-160V with some 200V capacitors from PC PSU 🙂
It put out about 90-100VAC RMS 🙂

2500W @ 4R and 1250W @ 8R
I use two 8R in series to get about 600W @ 16R 🙂
But IGBT can sustain 4R speaker 🙂

 

[Acca]

When I power a 2kW heater lamps in house blink 🙂
And it's simple in construction,less parts-less likely to blow up 😀