Success with class-d? - Page 3 - 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 26th May 2004, 11:41 PM   #21
diyAudio Member
 
Join Date: Dec 2003
Location: Orange County, CA
Default Self Oscillating Amps

I use three of the ICE Power self oscillating amplifiers in my product. See the PM-3 amplifier at www.rh.com. I have never had the slightest problem from intermodulation or anything else fromy having the amplifiers unsynced. And in heavy duty professional use, with over 1000 modules deployed we have had only one field failure.
__________________
Dan Fraser
  Reply With Quote
Old 27th May 2004, 01:32 AM   #22
diyAudio Member
 
Workhorse's Avatar
 
Join Date: Dec 2004
Arrow Commentable Thoughts

I would use only one High-linearity Triangular wave generator to fed 4 channels in my prototype.
THATS THE TRUE SYNCHRONISATION.
COMPLIMENTS
AMPMAN
  Reply With Quote
Old 27th May 2004, 06:11 AM   #23
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Quote:
I would use only one High-linearity Triangular wave generator to fed 4 channels in my prototype.
Maybe a high-precision triangular doesn't "travel well". So you might do it another way.

Regards

Charles
  Reply With Quote
Old 27th May 2004, 12:23 PM   #24
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
Quote:
Originally posted by ZeroTHD
Remember, I'm new to this, so don't be too hard on me.
Regarding choice of components. I picked components I have on the shelf for easy and cheap prototyping.
Thanks,
Anders
Right. Shoot-through.

The diodes on q5(?) and q11 won't be very effective... It's a baker clamp. You need a lower forward voltage than that of the cb diode of the transistor ie one schottky. Not a standard pn diode and certainly not two. The simulation won't catch this because recovery isn't very well modelled in spice.

Simulate one single driver with a mosfet with an ohmic load to get a feel for the kind of resistor values you need. Hint: only the 10 ohm resistors are correct.
Look at the gate wave form. If you want to prevent shoot-through the gate waveform should fall quickly.
  Reply With Quote
Old 27th May 2004, 12:34 PM   #25
Nisbeth is offline Nisbeth  Denmark
diyAudio Member
 
Nisbeth's Avatar
 
Join Date: Jan 2001
Location: Denmark
Quote:
Originally posted by demons_wing
would you have the web address maybe?
http://www.icepower.bang-olufsen.com/sw1061.asp


/U.
  Reply With Quote
Old 27th May 2004, 12:34 PM   #26
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
Default Self-oscillating

Self-oscillating amps are indeed liable to produce intermod tones. So far we've gone up to 5 channels x 100W crammed on a single PCB. The layout is a ***** but you can get the tones below a few tens of microvolts, which is acceptable. Besides, if you're a hobbyist - who cares if you try the water with mono blocks first?

A propos of this thread, Jan-Peter was wondering if the SODA modulator couldn't be released into the wild by now. I guess it can. It isn't nearly as good as the current state of the art UcD but I can't give you that yet of course. On the other hand it's already got one important thing: post-filter feedback. A disadvantage is that it doesn't like to be clipped without load. I'm leaving it up to your own imagination how to detect if the amp's gone oscillating at fres, but simply disabling and re-enabling the power stage is enough to get it back onto its feet.
Attached Images
File Type: gif sodasch.gif (6.2 KB, 505 views)
  Reply With Quote
Old 27th May 2004, 12:38 PM   #27
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Quote:
I'm leaving it up to your own imagination how to detect if the amp's gone oscillating at fres, but simply disabling and re-enabling the power stage is enough to get it back onto its feet.
One hint: re-triggerable monoflop

Regards

Charles
  Reply With Quote
Old 27th May 2004, 01:44 PM   #28
diyAudio Member
 
Workhorse's Avatar
 
Join Date: Dec 2004
Arrow Commentable Thoughts

Quote:
Originally posted by phase_accurate


Maybe a high-precision triangular doesn't "travel well". So you might do it another way.

Regards

Charles

HI Charles PLZ Clarify The Statement "Travel Well"

AmPmAn
  Reply With Quote
Old 27th May 2004, 01:48 PM   #29
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
I simply wanted to say that it might be difficult to distribute a clean and linear triangle over a wide area of a PCB, especially within a switching amp.

Regards

Charles
  Reply With Quote
Old 27th May 2004, 11:51 PM   #30
diyAudio Member
 
Workhorse's Avatar
 
Join Date: Dec 2004
Arrow Commentable Thoughts

Quote:
Originally posted by phase_accurate
I simply wanted to say that it might be difficult to distribute a clean and linear triangle over a wide area of a PCB, especially within a switching amp.

Regards

Charles

ThanX Charles , UR Great Suggestion Noted.
Meanwhile I will not route the triangle through large distances on PCB. All the Components are SMD type therefore space is very small and tracks are extremely short

AmPmAn
  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
simple se success! newtube Tubes / Valves 3 24th May 2009 09:23 PM
TDA7560 car amp, second try, success! Redshift187 Chip Amps 6 22nd September 2008 11:48 AM
First Re-Cap Success ! ! 65blkbkgt Car Audio 9 11th July 2007 07:47 AM


New To Site? Need Help?

All times are GMT. The time now is 07:50 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