Power Supply Resevoir Size - Page 113 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 14th September 2012, 02:56 AM   #1121
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by gootee View Post
The RC time constant is not a problem, when charging the decoupling caps on the amp board. You're thinking of the slower exponential decay of a larger capacitance's voltage, as it discharges current through a resistance. But look at the very beginning of that curve. There is no slow ramp UP to it. The current starts flowing blindingly quickly, and at its highest rate.

The power rails themselves do have resistance and self-inductance that could slow down the charging of the decoupling caps. But larger reservoir caps should only help make it faster and better for the decoupling caps, as far as I can see.
Nico's example is very frequently reported. The fix is easy (post#1115), but identifying the cause is totally a mystery to me. I wonder what situation keeps happening that slows down the reactiveness of the amp power bypass caps. So, would you say that the muddy blur of the overlarge example was from not responding fast enough for transients? Or would you say that the amp board power caps lost the competition for charge?

Question:
Did my schottky in post 1115 work by providing voltage drop, or did they work by preventing the charge from coming back out of the amp caps?
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.

Last edited by danielwritesbac; 14th September 2012 at 03:15 AM.
  Reply With Quote
Old 14th September 2012, 04:12 AM   #1122
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by gootee View Post
HOWEVER, that job, the "fast" part of it at least, will be handled by the DECOUPLING CAPS, which HAVE to be very near the points of load (to be fast-enough), not by the reservoir caps.

and big enough to make it on their own
fortunately they are getting bigger these days

what is a transient anyway ?
many think of it as a small exstra signal
I would rather say its the full signal, plus some exstra
which is why I say the last cap should be big enough to make it on its own, basicly
  Reply With Quote
Old 14th September 2012, 04:28 AM   #1123
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
A transient is that guy sleeping on the bus bench Just passing through, not staying around....
  Reply With Quote
Old 14th September 2012, 04:31 AM   #1124
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
sounds lonely
and when he gets on the bus, not alone I guess
  Reply With Quote
Old 14th September 2012, 04:33 AM   #1125
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Yes, but with a sign he collects cash and doesn't pay any taxes.......
  Reply With Quote
Old 14th September 2012, 04:37 AM   #1126
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
A transient is everything except for steady state. Steady state is a sine wave "tone", or more than one of them, that have been playing for a long time and are not changing their amplitude or frequency.

Last edited by gootee; 14th September 2012 at 04:41 AM.
  Reply With Quote
Old 14th September 2012, 04:43 AM   #1127
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
I thought a transient would be a natural part of a peak ?

and most music I listen to mostly consist of constant peaks and transients
  Reply With Quote
Old 14th September 2012, 04:47 AM   #1128
diyAudio Member
 
Join Date: Oct 2011
Yes Daniel it is preferable to clean the power before it gets to the transformer.
  Reply With Quote
Old 14th September 2012, 04:49 AM   #1129
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Seriously, "transient" is EVERYTHING that is not "steady state".
  Reply With Quote
Old 14th September 2012, 04:53 AM   #1130
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by gootee View Post
Seriously, "transient" is EVERYTHING that is not "steady state".
steady state doesnt sound like music to me
are you talking about test bench measurents ?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Valve power supply - How to size transformer? SanderW Power Supplies 25 4th January 2013 05:12 PM
How do you calculate choke size in a power supply? Original Burnedfingers Tubes / Valves 25 5th January 2012 01:23 AM
power supply bypass cap size BigE Power Supplies 11 5th July 2011 03:59 PM
Power Supply Case Size diymixer Power Supplies 1 10th October 2010 06:47 AM
What size power supply should I get for repair work? spooney Car Audio 3 7th December 2007 12:50 AM


New To Site? Need Help?

All times are GMT. The time now is 11:43 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2