Recent content by borysgo2

I have made another driver board for i-SMPS. This time it is based on UCC25600. Just take a look, a few components only, and you have : -very very low standby current (startup from the resistor !!), no extra transformer required -very powerfull driver IR2110 -soft start -two stage over current...

The last picture is the older project (developed for last two or three yeares). It is module amplifier (i-AMP), separate output stage and a few input stages (similar like slewmaster project at diyaudio.com). I have made 4 or more output stages, with bipolar transitors (2,3,4 pairs) and one...

The final test with amplifier. All stuff works fine, no fire, only nice sound :D Happy New Year for all. Regards Peter

Bellow pic of mounted heatsink with tranies and diodes. The SMD stuff at the secondary side is for speaker protection: - Delayed speakers turn ON - Fast speakers turn OFF - DC protect - AMP over temperature protect.

I didnt make measurements today but I have finished up the man board (the speaker protection).

A bit off topic but it might be helpfull. I have done some small tests on a new board, for now without tweaking the parts values. Bellow few scope readings how does the current sense work in more traditional aplication of half-bridge smps. Yellow trace --> primary voltage Blue trace --> current...

Thanks !! I have made a driver board prototype with SG very similar like from link above and it seem to work OK by pulling COMP pin to regulate PWM. For now I will have to finish up universal smps prototype from rubbish parts. Regards

I have made some small changes to speed up the protection a bit. Further tests in progress. Blue line is lower mosfet Vgs and the yellow line is voltage from those two 1uF caps connected in series at half bridge (AC component).

Good news, i-SMPS works fine from the first plug in. Next step is to do some tests.

Now it should be more clear. You can use splitted bulk capacitors + single series cap too.

Thanks for a document. Simulation only presents how it is working. Please take a look at the real animal bellow, the current is limited to the MAX that smps can handle safely (current is not rising above seted value), in my case 70kHz I have 14us in between the cycles so it is impossible to make...

wally It works very easy, It uses reactance of the capacitors. The picture bellow shows how it works. I am a bit angry that I have wasted so many time and mosfets trying to get current sense trafo + CT pin combo to work, and after a good few days I have found a solution but it costed me a lot of...

Small update. I have removed the current sense trafo and used instead capactive divider, it works perfect. The SMPS is very quiet at over load (no buzzz or hiss noises), the setup is dead simple and works perfect. The dynamics of the protection can be easily seated up with a few capacitors.

I have done some further work on the protection with IR2153, I think I know why so often it just sucks. If you are using open collector transistor or triac or mosfet to pull down Ct pin to GND make sure it is done very quick, otherwise your mosfets will be gone for sure. While pulling the Ct pin...

I have 2x680uF in series at primary (eqivalent 340uF). Trafo ratio is n=3. The secondary side capactance is 4x1000uF (2000uF per rail). I am getting ripple at secodary side exacly 2.8Vp-p. After adding another 2 caps 1000uF/200V at each rail (i have 840uF equivalent capacity at primary side), I...