Recent content by Pichou

Hi, Trying to define the snubber at primary side, but I don't understand something on your how to Silvio. First, I measure the ringing freq with the psu loaded on each output (total of 2.6A on primary at 12.35v). I found something like 14.7Mhz, it's very high....but the ringing is not a proper...

Hi Silvo, Tried 2 news transformers following your instructions with the same visible step on primary. Here is a photo of one transformer with only the primary and the 7 turns secondary. There is one winding of the 7 turns alone in the middle of the primary entry. Primary is made with 3x0.5 mm...

Hi, Here is a photo of the psu. Don't know if you can see it in large dimensions... Transfo is a PRIM 6+6T made with 0.7x1 / SEC1 11+11T with 0.5x1 / SEC2 7T with 0.6x1 RD 470R / CT 1nf / RT 15k / F=48khz R gate 11R + pull down 10K + Diode like your schematic. Fall and rise time are better ...

Some new screenshot of the gate signal direct with the probe on the pin of the mosfet. I think I have a good (the best) result without gate resistor. A little better slope if I put a 10K in pulldown. I have done some test still without gate resistor but with different value of the pull-down, and...

Hi, Thanks for your answer Silvio. I have done some tests and play with CT/RT/RD to obtain a 1µS dead time and the cleanest square signal I can with just the SG and driver. Ct is 1nF, RT is 15K, RD is 470R. The freq is around 47.5Khz. If I go lower for RD with 250R, dead time is 860ns. With the...

Hi ! The PSU seems to work properly ! I have play with the snubbers, but i think I don't need them, at the primary and secondary side, there is no overshoot or something strange, it's even the opposite. In attache a view of the mosfet command. Smooth square signal and little undershoot at the...

Sorry, missing the parts numbers on the schematics. I'm playing with Excellent IT, and I think the TN23 core I planned to use is not good. A TN26 will be better. Print screen in attache.

Hi Alls ! I'm freshly registered here, but I read you since many years. Now is my day to take the plunge and to show you my smps project. I don't have engineer knowledge, only school memories. Since the time I read the forum trying to understand the smps rules, I have now finished the...