Audiom | 100-W audio amp is 20 times more efficient than Class D chips - Page 2 - 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 6th October 2009, 04:42 AM   #11
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
I'm sure Mr. Bruno can explain what this is all about.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 6th October 2009, 06:00 AM   #12
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
To me it seems to be targeted at cheap boom boxes. The title 25 times more efficient than class-d is just marketing ** used as eyecatcher. What they do is achieving less IDLE losses than class-d. Which can not be neglected in battery powered applications that are just used for background listening.
On the circuit board pictured one doesn't see an output filter. Maybe it is a linear amp with a highly efficient PSU. Maybe it is a filterless class-d amp - in this case it is definitley targeted at cheap crappy products.

Regards

Charles
  Reply With Quote
Old 6th October 2009, 08:48 AM   #13
diyAudio Member
 
Saturnus's Avatar
 
Join Date: Jun 2005
Location: Copenhagen, Denmark
I think it's a mix of several technologies. Feed forward switching supply, filterless output, probably also some sound processing to filter out less dominant frequncies and emphasize dominant frequencies.

Definitely targeted at ultra-low end sound (think integrated speakers in mobile phones here). But still "20 times more effecient than class-D"? Load of **! The Tripath 2020 uses ~55mA in idle, or about twice as much a normal power LED, so if you include one you have raised the power consumption by 50%.

Last edited by Saturnus; 6th October 2009 at 09:14 AM.
  Reply With Quote
Old 6th October 2009, 12:02 PM   #14
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
For something that is (almost) idle more than 98% of the time there are definitley solutions that offer additional reduction of wasted power than ordinary class-d.

I don't think this chip is targeted at lowest-power applications like mobile phone but at boom boxes.

BTW: Really LOW power applications like mobile-phones and hearing aids are the areas that are mainly class-d nowadays. I was attending a class-d conference recently. A lot of topics covered small integrated class-d amps for mobile phones etc.

Regards

Charles
  Reply With Quote
Old 6th October 2009, 02:33 PM   #15
diyAudio Member
 
Join Date: Nov 2005
Location: colorado
Defineatly cheap aps. Maybe integrated on board PC sound, iPods, etc.
Rather interesting claims, though, and I agree that it is probably some
combinations of various technologies and may be indeed a bit more
efficient than Class D (but nowhere near the claims). I don't want to
buy any yet. But if somebody else wants to experiment in small amps,
it would be nice to have them give us results.
  Reply With Quote
Old 7th October 2009, 04:12 AM   #16
star882 is offline star882  United States
diyAudio Member
 
star882's Avatar
 
Join Date: Mar 2007
I'm not going to believe it at all until I can get the datasheets. And I won't fully believe it until I actually have one to play with. I'll power it with some supercaps and solar cells for the ultimate smug experience.
Actually, I'll power it with some CoolChips ( http://www.coolchips.gi/ ) running in reverse. (Unlike solar cells, a custom machined copper rod thermal collector will work indoors in total darkness, but would be very awkward to use outdoors. So solar cells for outdoors, thermal collector for indoors.)
__________________
"Fully on MOSFET = closed switch, Fully off MOSFET = open switch, Half on MOSFET = poor imitation of Tiffany Yep." - also applies to IGBTs!
  Reply With Quote
Old 7th October 2009, 05:07 AM   #17
diyAudio Moderator Emeritus
 
Iain McNeill's Avatar
 
Join Date: Oct 2007
Location: Santa Cruz, California
That could be the perfect application. If you can charge some VERY LOW ESR caps with solar cells, and do a good job with the power device PCB layout you could have a winner.

Very interesting.
  Reply With Quote
Old 7th October 2009, 06:50 AM   #18
MOER is online now MOER  United States
diyAudio Member
 
Join Date: Aug 2003
Location: SIMI VALLEY CA
Default Class D efficiency

Class D amplifiers are NOT 70% efficient or anything close.

A class D amplifier at idle is 0% efficient.

A class d amplifier at clip into a load which does not push the RDs on to its limits is 90%+ efficient BUT with a sine wave....last time I looked nobody was actually listening to sine waves.

So the typical efficiency of a class D amplifier with average music into a reasonable load with the musical peaks just at clipping is well below 70%

Drive your class D with pink noise at 1/8 of rated power = typical program material with occasional clipping and then measure the efficiency and post that result
  Reply With Quote
Old 7th October 2009, 07:16 AM   #19
diyAudio Moderator Emeritus
 
Iain McNeill's Avatar
 
Join Date: Oct 2007
Location: Santa Cruz, California
agreed, the efficiency spec is pure bunkum.
  Reply With Quote
Old 7th October 2009, 09:45 AM   #20
Hurtig is offline Hurtig  Denmark
diyAudio Member
 
Join Date: Feb 2005
Location: Denmark - Århus
Quote:
Originally Posted by DSP_Geek View Post
20 times more efficient? Gee, worst-case class-D is 70% efficient, so this thing must be 1400% efficient! Call the Nobel Prize committee, we've discovered the secret of endless power!

That's what happens when you let the marketing pukes put out a press release before the engineers fact-check it.
Read all the info, before trashing the chip. The 20 times more efficient is at low levels.
I do NOT know any class-D with 70% efficiency at low levels, since the "household-consumption" in the amp typiclly consumes some watt's. And at ex 0,1 watt output, the efficiency is very low.
  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
12VDC Class-D Chips speaker Class D 3 9th February 2008 12:42 PM
Class D PWM chips wassyq Class D 1 3rd October 2007 09:59 PM
Efficient sub for Omnes Audio L8's inrank Subwoofers 15 19th October 2006 12:05 PM
Need help getting info on Class H+ chips DonoMan Chip Amps 4 20th October 2005 08:11 PM
good class d chips sagarverma Class D 0 8th October 2005 07:46 AM


New To Site? Need Help?

All times are GMT. The time now is 03:48 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