Self Oscillating Class D - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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 25th January 2009, 10:01 PM   #1
jony is offline jony  Poland
diyAudio Member
 
Join Date: Jun 2004
Location: wroclaw
Default Self Oscillating Class D

Here is the simplified schema of a self-oscillating class D amplifier.
Click the image to open in full size.
Can anyone explain it to me how this circuit work.
Maybe some intuitive approach help me understand this circuit.




PS I attach "full" circuit
Attached Images
File Type: png 78_1232569987.png (27.8 KB, 1225 views)
  Reply With Quote
Old 17th February 2009, 03:33 AM   #2
diyAudio Member
 
Join Date: Sep 2005
Send a message via AIM to itsmrdavid
That looks interesting enough to try on a bread-board...

Here's my take on your question: take a look at the theory for a "buck converter" power supply circuit... It's a pretty simple thing.
Hysteretic control style has a coil, just like this circuit.

I was looking at buck converter designs a while back, and thought
to myself: "what if I modulated the control for the output voltage?"

I think that's pretty much what's happening here.

The only trouble - audio wise - is when you load the output, the oscillation frequency changes, and it probably changes gain, etc...

~David
  Reply With Quote
Old 18th February 2009, 02:56 PM   #3
hreith is offline hreith  Germany
diyAudio Member
 
hreith's Avatar
 
Join Date: Jun 2004
Location: Heidelberg
It's a SODA from Bruno Putzeys.
  Reply With Quote
Old 18th February 2009, 08:53 PM   #4
tiki is offline tiki  Germany
diyAudio Member
 
tiki's Avatar
 
Join Date: Feb 2004
Location: Dresden
Hallo Hubert,
immer schön am Ball bleiben!
Beste Grüße, Timo
__________________
tiki
  Reply With Quote
Old 19th February 2009, 03:13 AM   #5
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
It looks like a mix of hysteresis and phase shift oscillator.

Read this paper, it gives a brief explanation of both approaches:
http://www.ciaudio.com/ucd_aes.pdf
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 23rd February 2009, 09:56 AM   #6
GGEC is offline GGEC  China
diyAudio Member
 
Join Date: Jun 2007
Default I want to see something PDF file.

"An Asynchronous switching High-end Power Amplifier" Presented at the 112th AES Convention Preprint 5503.

"A Novel Audio Power Amplifier Topology with High Efficiency and State of the Art Performance" Presented at the 109th AES Convention Preprint 5197.

My E-mail: hrz709@163.com

Thank you!
  Reply With Quote
Old 23rd February 2009, 10:03 AM   #7
diyAudio Member
 
Ouroboros's Avatar
 
Join Date: Dec 2003
Location: Nottingham UK
I've just emailed you a copy of the first document. (It's the Mueta paper).
  Reply With Quote
Old 23rd February 2009, 01:27 PM   #8
jony is offline jony  Poland
diyAudio Member
 
Join Date: Jun 2004
Location: wroclaw
Thanks for help
Now I "understudy" that this circuit work as a simple opamp oscillator
Click the image to open in full size.

Here is the link to
"A Novel Audio Power Amplifier Topology with High Efficiency and State of the Art Performance"
http://www.icepower.bang-olufsen.com...ntion/5197.pdf
Attached Images
File Type: png 97_1233105218.png (13.3 KB, 629 views)
  Reply With Quote
Old 23rd February 2009, 01:33 PM   #9
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Google SOPA or self oscillating power amplifier. There's a group of industry/university folks in Europe that have been trying for years to convert ADSL over to a CMOS SOPA architecture. They have lots of good theoretical papers dating back 8-9 years. The best was a differential one with lots of harmonic cancellation (almost magical).
__________________
Silence is so accurate.
  Reply With Quote
Old 24th February 2009, 12:44 AM   #10
GGEC is offline GGEC  China
diyAudio Member
 
Join Date: Jun 2007
Thank you Ouroboros & jony!
  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
Explanation of Self Oscillating Class D Genomerics Class D 19 29th October 2006 04:31 AM
TDA7294 in self- oscillating class-D Kuzmenko Class D 1 24th November 2005 02:16 PM
Non clocked (e.g. free running, self oscillating) class d analogspiceman Class D 27 14th November 2004 07:40 AM


New To Site? Need Help?

All times are GMT. The time now is 07:30 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