ucd 25 watts to 1200 watts using 2 mosfets - Page 6 - 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 17th May 2010, 06:50 AM   #51
MOER is offline MOER  United States
diyAudio Member
 
Join Date: Aug 2003
Location: SIMI VALLEY CA
Default Ucd

I have examined the schematic and there are several issues which will cause serious problems.

1) There is no provision for any dead time
2) The MOSFETs shown are old, slow and are not suitable for high frequency switching
3) The gate resistors should be reduced to about 4.7 ohms and use IRFP4229 or some of the newer INFINEON MOSFETs which are superb.
4) The snubbers across the output MOSFETs reduce the resistor values to about 10 ohms.
5) Use 0.1mfd 100v chip caps ate the actual pins of the MOSFETs to ground (Upper Drain and lower Source)
6) Use a bunch of 0.1mfd 200v chip caps from +40v to -40v as close to the MOSFETs as possible.
7) The UF4004 bootstrap diode is too slow use a 35nsec 200v diode.
8) To keep the output offset low a servo MUST be used from speaker output to LM311 pin 2

Steve
  Reply With Quote
Old 17th May 2010, 07:27 PM   #52
qsa is offline qsa  Germany
diyAudio Member
 
qsa's Avatar
 
Join Date: May 2007
Quote:
Originally Posted by MOER View Post
I have examined the schematic and there are several issues which will cause serious problems.

1) There is no provision for any dead time
2) The MOSFETs shown are old, slow and are not suitable for high frequency switching
3) The gate resistors should be reduced to about 4.7 ohms and use IRFP4229 or some of the newer INFINEON MOSFETs which are superb.
4) The snubbers across the output MOSFETs reduce the resistor values to about 10 ohms.
5) Use 0.1mfd 100v chip caps ate the actual pins of the MOSFETs to ground (Upper Drain and lower Source)
6) Use a bunch of 0.1mfd 200v chip caps from +40v to -40v as close to the MOSFETs as possible.
7) The UF4004 bootstrap diode is too slow use a 35nsec 200v diode.
8) To keep the output offset low a servo MUST be used from speaker output to LM311 pin 2

Steve
Im a little confused because in Spain DIY Forum the amplifier should working very good..

can you add important changes in schematic and share your experience and knowledge with us ?
  Reply With Quote
Old 18th May 2010, 12:33 AM   #53
diyAudio Member
 
andrewlebon's Avatar
 
Join Date: Feb 2008
hi workhorse
greetings any comments on schematic any mistakes any sugesstions with your expertise this project can be possible for all d class
fans hoping you can help
thanking you
andrew lebon
  Reply With Quote
Old 18th May 2010, 02:57 AM   #54
diyAudio Member
 
Join Date: Nov 2009
Location: Pune
Quote:
Originally Posted by andrewlebon View Post
hi diyers
greetings can this circuit work are there any flaws
thanking you
andrew lebon
this might help. also use same translator. Google Translate
__________________
There is always a first time....
  Reply With Quote
Old 18th May 2010, 03:32 AM   #55
diyAudio Member
 
Join Date: Nov 2009
Location: Pune
Quote:
Originally Posted by andrewlebon View Post
2 details of coil 33uh wire diameter no of turns core diameter

Shavano Music Online - Cross-Over Network; Air Core Inductor Calculator

Use above link

Hey and did u check about availability of IR2110 and other components? I fear it might not be easily available here in India.


And guys. can anyone provide TS of this amplifier. ( like Frequency response, Inter-modulation distortions, THD, slewrate)
__________________
There is always a first time....

Last edited by Aucosticraft; 18th May 2010 at 03:52 AM. Reason: Incomplete
  Reply With Quote
Old 18th May 2010, 09:04 AM   #56
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
Quote:
Originally Posted by qsa View Post
Im a little confused because in Spain DIY Forum the amplifier should working very good..

can you add important changes in schematic and share your experience and knowledge with us ?
In the kingdom of the blind the one-eyed are kings, but here we are in a two-eyed forum.

This amplifier in some cases can play loud music without overheating or destroying itself, but the design is full of pitfalls. In fact, those pitfalls make the result quite random, some units will work and some won't, depending on parts, etc... (too many parameters overlooked by the designer).

Electromagnetic interference will be quite high too.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 19th May 2010, 12:40 PM   #57
diyAudio Member
 
Reactance's Avatar
 
Join Date: Jun 2005
Location: Cape Town
Quote:
Originally Posted by Eva View Post
In the kingdom of the blind the one-eyed are kings, but here we are in a two-eyed forum.

This amplifier in some cases can play loud music without overheating or destroying itself, but the design is full of pitfalls. In fact, those pitfalls make the result quite random, some units will work and some won't, depending on parts, etc... (too many parameters overlooked by the designer).

Electromagnetic interference will be quite high too.
Always complaining and criticizing other peoples work. its a good starting point no one has provided a better simpler class-d solution not even you, and yes, your good clever answers can only help so far.
__________________
There’s nothing worse than the smell of burned output transistors!!
  Reply With Quote
Old 19th May 2010, 01:39 PM   #58
81bas is offline 81bas  Germany
diyAudio Member
 
Join Date: Jan 2006
Location: Kiel
Quote:
Originally Posted by Reactance View Post
Always complaining and criticizing other peoples work. its a good starting point no one has provided a better simpler class-d solution not even you, and yes, your good clever answers can only help so far.
Have you already tried to build this simple amp with its "very good component selection"? Any photos?
  Reply With Quote
Old 19th May 2010, 02:58 PM   #59
diyAudio Member
 
Reactance's Avatar
 
Join Date: Jun 2005
Location: Cape Town
Quote:
Originally Posted by 81bas View Post
Have you already tried to build this simple amp with its "very good component selection"? Any photos?
no but you don't see me complaining and criticizing other peoples work i take you and eva have something in common then.
__________________
There’s nothing worse than the smell of burned output transistors!!
  Reply With Quote
Old 19th May 2010, 04:24 PM   #60
81bas is offline 81bas  Germany
diyAudio Member
 
Join Date: Jan 2006
Location: Kiel
Quote:
Originally Posted by Reactance View Post
no but you don't see me complaining and criticizing other peoples work i take you and eva have something in common then.
just try to build this amp and get it working, it is "so simple" (please do not forget to post some photos). I am pretty sure, there will be some troubles with it, but we do not see you complaining and criticizing then
  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
Philips 40/25/15 watts amplifier with Universal preamplifier circuit. renjiish Solid State 64 28th July 2014 11:33 AM
Decibel Watts VS Watts ? fivestring Solid State 11 1st April 2009 01:08 PM
AMP1-B: why only 25 watts @8ohms? theAnonymous1 Class D 10 15th August 2005 06:55 PM
Sound quality of amps at 0.3 watts vs @ typical 5 watts rick57 Solid State 2 26th March 2005 06:25 AM
Need 2 watts Vivek Everything Else 4 17th July 2003 08:29 AM


New To Site? Need Help?

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