digital question

[kees52]

Hi All

I am busy with a high power smps, I go for fase shifted zero switching type for welding.

These idea I did see has a extra line for switch a auxillary igbt to get a low loss effect and zero voltage switching, however, I need that extra signal.

on the photo it is seen as Q5 switch. I can use a comparator so I can adjust also on time for these switch, on pictures I hope it is more clear, I go try it in sim.

Precision is needed, an comparator needs 1 % timing components?

But maybe there is a other way to do, I do not use a dsp what is original used as part of the welder.

UC3875 or 79 has no extra output for the extra switch output so I need make one, I can use the output transitions
to trigger this like I did see on the picture timing chart.? a comparator for example, because puls length is twice the on delay.

thanks in advance.

kees

 

[kees52]

I think it is not needed anymore because I have found a passive version of zvs with a coil.

these are completely zero switching also with low load.

I go try this on sim with a fase shift UC3875 chip, also nice for power supplys for amps..

regards

kees

 

[29285]

It could be helpful if you would post the full link to that circuit.

 

[kees52]

It could be helpful if you would post the full link to that circuit.

Yes you are right, pdf are to big, I put links.

www.yildiz.edu.tr/~fbakan/AGK/agk_odev/4.pdf

http://www.google.nl/url?sa=t&rct=j...CYegqvAuiY32qGA&bvm=bv.76802529,d.ZWU&cad=rja

http://www.google.nl/url?sa=t&rct=j...QZzWwDxdUxUh9dQ&bvm=bv.76802529,d.ZWU&cad=rja

Last pdf (see zip file) is also interesting, timing here, possible with some electronics for Q5 and Q6 switches?

There are a lot more there of this very high efficienty power inverters.

search for them.

greetz

kees