Power Supply Resevoir Size - Page 189 - 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 31st March 2013, 07:33 PM   #1881
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
Note the unloaded noise. The toroid uses grain oriented steel. I think that makes a difference. But also check Tamura I think they make a flatpack.
  Reply With Quote
Old 31st March 2013, 10:36 PM   #1882
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
Demian

http://www.tamuracorp.com/clientuplo...PF24series.pdf
  Reply With Quote
Old 31st March 2013, 10:41 PM   #1883
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
Thanks. I wish they had a way to specify acoustic buzz. I'll get some samples and try them.
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 31st March 2013, 10:48 PM   #1884
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
I have trouble believing those aren't defective. My samples are only a few months old.
  Reply With Quote
Old 31st March 2013, 11:52 PM   #1885
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
I have more than one. I'll check the others. We will be on the phone to Signal first thing tomorrow.
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 2nd April 2013, 12:22 AM   #1886
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by Fob View Post
I think the question is more complicated than it looks. Depends of PA topology, PS type and so on. I'll give an example.
There was japanese patent from '70s that prevent voltage drop to driver stages. The sound quality improvement is significant. There is more issues. No one rectifier 'love' big capacitors. . . .
Click the image to open in full size.
You can connect an LM1875 or LM4702 at the spot marked driver stage, and all of the diodes sturdy schottky.
In either case, the high current hookup is the speaker return cable going to the 0v tap on the far left side of your diagram, right at the large caps.
D1 and D2 have prevented C1 and C2 from slowing down C3 and C4. So, by using the diodes, the decoupling has worked.
Kudos!
Yay for not driving with the parking brake on!!
It answers Nico's question at post1, post8, post9 about large capacitance sounding dull. Yes, one possible answer is to insert a diode (or a regulator could be used for a more orthodox appearance). So, if you want the fresh sound of small caps, you insert a really creative passive or an active or in fact use small caps.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.

Last edited by danielwritesbac; 2nd April 2013 at 12:33 AM.
  Reply With Quote
Old 2nd April 2013, 07:05 AM   #1887
rfj5106 is offline rfj5106  United States
diyAudio Member
 
Join Date: Mar 2006
Location: Richmond, B.C CANADA
I am building a power amp using a Meanwell 48V @7.5 amp power supply to power 'Sure Electronics' Digital Amplifier board rated at 300 wpc @ 4 ohms. I expect this rating is probably optimistic but how much capacitance would be recommended for this combination?
__________________
Richard Jenkins
  Reply With Quote
Old 2nd April 2013, 07:21 AM   #1888
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Default "Safety-Sized" transformer

With the source of these pulses the bridge rectifier output, shorter length pulses = less power.
Quote:
Originally Posted by gootee View Post
But for our simple case, generally, the larger the reservoir capacitance is (or the lower the ripple p-p voltage is), the shorter the pulses are.
So, bigger capacitance = less power. Yes, that's bound to happen when the transformer current, is sized during transformer purchase, below output device capacity, as protection. That's a good thing except. . . That's when it is possible to overwhelm the transformer with too much capacitance and incur that muddy "parking brake" like problem.
Like this:
When the transformer is near maxed out, quite busy both running and smartly protecting the audio amplifier, there's a limited amount of capacitance that it could charge brim full while in this condition.
What is?
Can we relate a transformer in strained condition to a chart with VA and max capacitance?

I end up considering Parallel output devices and monobloc/dualmono builds in order to get enough transformer to charge the power board, without enough transformer to overwhelm the outputs/fuses. So far, that consideration works, but sizing the power board perfectly is still not easy.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 2nd April 2013, 07:32 AM   #1889
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by rfj5106 View Post
I am building a power amp using a Meanwell 48V @7.5 amp power supply to power 'Sure Electronics' Digital Amplifier board rated at 300 wpc @ 4 ohms. I expect this rating is probably optimistic but how much capacitance would be recommended for this combination?
As much as you can spring for I'm currently using a Meanwell 18V supply for my chipamp (which is an analog one, not classD) and I have a 4 pole LC filter to remove as much as possible of the switching frequency (which I think is around 40kHz). With SMPSUs and classD amps the impedance of the capacitors is at least as important as the total value as they generate huge amounts of HF hash. So be sure to use low ESR types and parallel them up.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 2nd April 2013, 07:45 AM   #1890
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by danielwritesbac View Post
With the source of these pulses the bridge rectifier output, shorter length pulses = less power. ............
What does this mean?
Where did it come from?
Please answer in plain english.
__________________
regards Andrew T.
  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 04:12 PM
How do you calculate choke size in a power supply? Original Burnedfingers Tubes / Valves 25 5th January 2012 12:23 AM
power supply bypass cap size BigE Power Supplies 11 5th July 2011 02:59 PM
Power Supply Case Size diymixer Power Supplies 1 10th October 2010 05:47 AM
What size power supply should I get for repair work? spooney Car Audio 3 6th December 2007 11:50 PM


New To Site? Need Help?

All times are GMT. The time now is 10:03 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