Snubber Calculator

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procedure

Hello,
Please, I want to know if a transformer has two secondary, two bridge (CR21 = kpbc2504, Cr17-20 = 1N4007) connected as in the picture I posted, is it need a snubber per branch, ie a total of 4 ?, because the + and -.
This transformer audible and tedious 100Hz.les measured resonance inductances are not equal, I have no oscilloscope to measure the parasitic capacitance, but if someone just tell me if the procedure is correct.
 

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The translation of the text above is not correct, I presents the corrected text.

Hello,
please, I wanted to know for a transformer with two secondary, two bridge (CR21 = kpbc2504, Cr17-20 = 1N4007) connected as in the picture I posted, if you need a snubber by branch 4 in total, due to the + and -.
This transformer has a resonance at 100Hz.,
it is audible and annoying, if I measure the series inductance coils 31volt (I measures in pairs, with the primary shorted) the inductance is not equal, I measure with philips pm 6303 lcr, the measurements are to 1kHz ..
I read on the meter, capacitance, but only with non shorted winding, is that it is the parasitic capacitance?, or the capacitance between windings, or an oscilloscope is required for this measure.
Is that so far, the procedure sounds correct?

Thank you,
Best regards
stefano
 
Hi Stefano.

Sorry for the delay. You could try one snubber across the AC inputs to CR21 (as close to the secondaries as possible) and another across points 36 & 36.

Treat your multiple secondaries to CR21 as one secondary, taking necessary measurements from where your snubber will go. You will need a sinewave generator and by clicking the green boxes on the spreadsheet you'll get the help dialogue.

Don't know if a snubber will solve your problem though. If this is audible buzzing from the TX which was not previously there, could this be loose laminations? What circuit is this?
 
Almost solved

Hello,
thank you for yours answer , no brobleme for the delay , because in the meantime , I found part of the problem :
when I rebuilt this amp, on the PSU board, I have put 1N4007 diodes ( original4003 ), but on the pcb audio I mistakenly installed diodes UF4007 , apparently , the amp n ' not like fast diodes , so before putting standard diodes, I put on fast diodes as the PSU Board, just to see if the noise increased , the noise is effectively increased.
Now as you can see from the picture I drew of " circles " red marks were raised , by dint of desoldering and soldering ,
because the wire of the transformer are not flexible but rigid.
Traces no longer flat , I think it also affects the noise.
In the near future , I want to install one transformer per channel, making it dual mono fully and remove PSU Board , the original transformer is toroidal with respect to drawing I made ​​in my last post , it has no screen between primary and secondary , not grounding (I had to put it in the resin because there was a vibration from the coil.
With these changes , I hope to do without snubber .

Thank you,
Best Regards
Stefano
 

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