I some questions regarding the 4 .01 uF capacitors in the power supply:
1) I've never seen capacitors across each diode in a full wave bridge rectifier. Does anyone know the purpose of these caps? They aren't filter caps.
2) What type of caps are these and what voltage?
Thanks!
#183 5th Generation ODS Skyliner. Layout/Schematic Discussion
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Re: #183 5th Generation ODS Skyliner. Layout/Schematic
I believe, the .01 caps across the diodes are to help prevent switching noise from 1N4007-ish diodes. They are ceramic, 1000v, and unnecessary ( overkill? ) with "modern" ultra-fast UF4007 diodes. I think there is a discussion at el34world.com.
Bob Simpson
Bob Simpson
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#183 5th Generation ODS Skyliner. Layout/Schematic Discussion
Moving the comments from the files section to a discussion topic. Please remember to discuss and ask questions in the "Discussion" topics and keep the files threads clean of questions and commentary.
This refers to the files topic: http://ampgarage.com/forum/viewtopic.php?f=5&t=13095
This refers to the files topic: http://ampgarage.com/forum/viewtopic.php?f=5&t=13095
tUber Nerd!
Re: #183 5th Generation ODS Skyliner. Layout/Schematic
Thanks Bob. That makes perfect sense.Bob Simpson wrote: ↑Tue May 09, 2017 2:54 pm I believe, the .01 caps across the diodes are to help prevent switching noise from 1N4007-ish diodes. They are ceramic, 1000v, and unnecessary ( overkill? ) with "modern" ultra-fast UF4007 diodes. I think there is a discussion at el34world.com.
Bob Simpson
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Re: #183 5th Generation ODS Skyliner. Layout/Schematic Discussion
BTW I should have replied on this too, Bob's 100% right, they're just a protection measure. They may be overkill but those caps are super cheap too, and not a big 'expense'. Yes modern diodes are much safer too, and maybe not as necessary anymore. I had a Vox AC100 that had this setup and I stripped out the board to build a Vox AC100/2 from back in the early 60's Vox Days in the chassis but I kept that diode/cap layout like the original did.
I've also since seen it in other power supplies (not all amp ones) and it seems to be used only sometimes.
~Phil
I've also since seen it in other power supplies (not all amp ones) and it seems to be used only sometimes.
~Phil
tUber Nerd!