Is this more like it? How do you know when enough is enough? Resistance is 29.8 ohms.
Thank you for the replay. man I realized the problem now.. 150n is rated to DC 1kV..! it’s AC 600V. 10n is AC 1kV… I should
..fix this immidiately. (somewhat the last post was incompleted)
Fortunately the AC600V cap was hang in there without any issue.
I temporarily gutted out a same snubber set from another application- which was on a bridge rect., no audiable noise with or without the snubber though -, and used it on this. whew.
Fortunately the AC600V cap was hang in there without any issue.
I temporarily gutted out a same snubber set from another application- which was on a bridge rect., no audiable noise with or without the snubber though -, and used it on this. whew.
Hi folks, reading more about the use of the Quasimodo I got the impression that if your transformer has dual secondaries, then you should short not only the primary, but the secondary that is not currently under test. In doing that it reduced the resistance needed. So my current resistor snubber should be about 22 ohms.
Let me know if what I see on the scope meets expectations.
Thanks,
John
Let me know if what I see on the scope meets expectations.
Thanks,
John
Attachments
There are past comments on the default shorting of the untested secondary, compared to iteratively fitting a C-RC snubber in lieu of a short, as that is what be installed in-situ.
Indeed there is information on the default shorting of untested secondaries. Weeding through over 2,600 comments to find it is the problem I have....,,
post 2368 is one example. https://www.diyaudio.com/community/...-using-quasimodo-test-jig.243100/post-7247275
You are right. I've read Mark's white paper more than once, but shorting multiple secondaries other than the one under test in addition to the primary did not sink in to my understanding. I'm an implementor, not an engineer. When I read technical papers, my understanding of what I read is often limited by my lack of experience with the subject matter. Fortunately for me there are patient people like you and Mark that get me through.
This snubber exercise is going into my build of a Wolverine amplifier. The amp will have a dual transformers/power supplies. I'm just at the point where I will be testing the IPS and amplifier boards, but I circled back to the power supplies when another generous diyaudio person gifted me the bare Quasimodo pcb.
Thanks for your help with this,
John
This snubber exercise is going into my build of a Wolverine amplifier. The amp will have a dual transformers/power supplies. I'm just at the point where I will be testing the IPS and amplifier boards, but I circled back to the power supplies when another generous diyaudio person gifted me the bare Quasimodo pcb.
Thanks for your help with this,
John
can anybody help ? trying to find rs value
i have a toroidy supreme audio grade v2 TSAS400 va single 240v 2 x 18v.
i have looked on quasimodo results only.
closest i could find was toroidy audio grade 400va single 230v 2 x 18v.
found 2 different results for the same transformer
cx 10nf , cs150nf , rs 10 ohm
cx 10nf , cs150nf , rs 13 ohm
i have a toroidy supreme audio grade v2 TSAS400 va single 240v 2 x 18v.
i have looked on quasimodo results only.
closest i could find was toroidy audio grade 400va single 230v 2 x 18v.
found 2 different results for the same transformer
cx 10nf , cs150nf , rs 10 ohm
cx 10nf , cs150nf , rs 13 ohm
hi 6L6 , thanks for your reply. I dont have any 10-20ohm need too buy.
There is quite a few values between 10 - 20ohm, what should i get 15ohm ?
thanks magnus
There is quite a few values between 10 - 20ohm, what should i get 15ohm ?
thanks magnus
Hi All,
I just finished my Quasimodo and I thought I'd read everything, but I obviously missed the information about the caps... Where can I find this information, or what specifications should each cap have? Thank you in advance.
Okay, that was unnecessary. I was a bit confused by the discussion about 1 kV for the caps. According to the BOM, anything over 30 V is fine. Or am I misunderstanding something again?
The capacitor needs to be rated appropriately for the expected AC voltage it will be exposed to - for example, if you are using a transformer with 50VAC secondaries, I’d choose a capacitor rated for at least 63VAC… which is to say, AC rating should be somewhat higher than the expected voltage.
Higher voltage rating is fine, of course. Lower voltage rating is to be avoided.
Higher voltage rating is fine, of course. Lower voltage rating is to be avoided.
Thanks Jim! So all of this doesn't apply to Quasimodo, but to the real-world operation of the snubber caps - then everything is clear, I was aware of this requirement.