Offline full-bridge SMPS… need help

class d project

Luka & N-Channel

I sent an email to Michael Price the young man in the photo and he has responded that there is no pdf file only his notes and schematic, pcb layouts and other doc's which he is going to send me . They never got the HB power supply to work but the amp does work and is about 60 watts. I will keep all informed as I can use my supply with it.

chas1
 
Hi

Thank you for sending him email, I searched all google and found nothing but the site that I gave.

It was a pdf file but anyone could make it, I just assumed he did had.

When you get the files, can you send them to me, I make PDF and post it here.

I liked this project because it had it all, the pfc, smps and amp, although something didn't work as I remember and now that you said.
 
Luka & Chas1,

That would be great. I agree with Luka, PFC+SMPS+Amp. Not too eager to dive into the amp section yet- I'm just not ready to tackle another unfamiliar field yet, but the PFC & the SPMS main section, yes.

I wonder what the failure mode was for Michael's Power supply.
Hey Chas, Perhaps you could invite him to the forum. :idea: This might facilitate all of our interacting with him.

Just a thought. (I have those from time-to-time. :xeye: )

Steve
 
Yeah, that is a good idea. Since he is a student, this would open up a whole new arena and source of info for him to both give and receive.

Been to MIT. Impressive EE Program. Took part in an SAE-sponsored Consortium on 42V, but as 42V died a quiet death, so did the Consortium. :dead:
 
Hi

Hopefily this will be the last version, HB with FB, working on mains at 500w or more.

Clip2.jpg
 
Hi

I will try it with zener and opto just to see if it will work now, since there is none high freq. just a bit of primary side ripple. But in the end I think I will anyway end up with TL, because it is not difficult to change to different output voltage + you can have compensation. I don't have the board from the pic made yet, I have to think what else I would like to have on it like regulated voltage for op amps, fans...

Do I remember right when I say that your supply is working too?
 
feedback

Luka

There are high end commerical amps that do not use regulation in thier supplies, one that comes to mind is Crown. The key is does it supply the load requirement without any harmonic's or excessive noise and the distortion levels are within spec's. You might want to check the outputs with a low level pulse. I think I have your correct output circuit component value's, verify that this info is correct. Np = 35 turns, Ns = 7 turns each and Lo is 30 uh along with Co of 1000 uF on each rail or you using the (2) 2200 uF in each rail. I will design a feedback using a TL431 along with MC8102 that should be suitable. It will only monitor the postive rail but the outputs should be symmetrical. You can check the supply with and without the feedback.
chas1
 
Hi

Now I'm trying it with toroid core, looks very promising, but I would like to get rid of the spikes/oscilations as much as possible.
This is all on primary side so where do I start, what kind of snubber will a need?

This is still half-brigde, Vin is 32V, scope was set to 5v/div and 2us/div

P1010022.jpg


This one is zoom in of bottom oscilation, osc set to 5v/div and 0.05us/div

P1010024.jpg


Any suggestions?