ucd 25 watts to 1200 watts using 2 mosfets - Page 176 - 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 9th March 2012, 01:53 PM   #1751
CPX is offline CPX  Romania
diyAudio Member
 
Join Date: Nov 2004
Location: Cluj
manojtm :
irfb4227 has 46A and 200 volt rating..you can use 2 of them...but ir2110 can not drive more than one Qg~100nC pair mosfets.irf240 is a low current easy driven Qg<40nC mosfet..that is why it works for you...

When designing switching electronics pcb you mush have VERY SHORT TRACES and lots and lots of ground(ground plane on one side).
Look at the original board an this thread..is very good

I do not understand why you need an alc chip..you should use a subsonic filter..but i am using a current level limiter .

Last edited by CPX; 9th March 2012 at 01:57 PM.
  Reply With Quote
Old 9th March 2012, 02:26 PM   #1752
manojtm is offline manojtm  India
diyAudio Member
 
manojtm's Avatar
 
Join Date: Aug 2008
Hi CPX,

IR2110 can handle 2A Current
you are correct RF side must have very short traces and GND plane
My older design OSC = 125KHz and used long traces 1mm thick; No problem found
  Reply With Quote
Old 9th March 2012, 02:32 PM   #1753
CPX is offline CPX  Romania
diyAudio Member
 
Join Date: Nov 2004
Location: Cluj
Yes 2A is enough for 100nC and 4500pF but no more...
125 khz is a very low of., anyway you can not say "no problems found" without making THD and IMD tests at high current...music is not a valid testing method
  Reply With Quote
Old 9th March 2012, 03:13 PM   #1754
Dimonis is offline Dimonis  Russian Federation
diyAudio Member
 
Dimonis's Avatar
 
Join Date: Mar 2011
Location: RF 33 Vladimir
Quote:
Originally Posted by CPX View Post
Yes 2A is enough for 100nC and 4500pF but no more...
I agree and not , depends on frequency , at about 300kHz your figures are right , but the 2110 will be hot , if freq lower it can drive more , proportional.

Last edited by Dimonis; 9th March 2012 at 03:17 PM.
  Reply With Quote
Old 9th March 2012, 05:07 PM   #1755
norazmi is offline norazmi  Malaysia
diyAudio Member
 
Join Date: Feb 2008
damn, this thread hot again, anyone willing to sacrifices mosfet or ir2110 and do experimenting in real life until success follow by simulation first. one thing i take note from iraudamp9 desing, they use bjt buffer to parallel the mosfet with irs2092, this cannot be applied to ir2110?
  Reply With Quote
Old 9th March 2012, 05:18 PM   #1756
CPX is offline CPX  Romania
diyAudio Member
 
Join Date: Nov 2004
Location: Cluj
dimonis:
Yes..i am thinking 300khz...anything lower than 250 khz and the audio band gets too narrow for my taste.

norazmi:
Bjt buffer is feasible with ir2110 but the switching may not be so clean,i prefer dedicated driver, but for my needs(max 500W) one pair of mosfets in enouth.
  Reply With Quote
Old 9th March 2012, 05:30 PM   #1757
norazmi is offline norazmi  Malaysia
diyAudio Member
 
Join Date: Feb 2008
500w into 8 ohm? its loud enouh and will vibrate ur house hard hehehe.. 300Khz... hmmm i`ve tried before increase freq at approx 500 Khz, mosfet survive and run with cool condition, but the only one hot is filter caps 1uf, huh.... so im worried it will explode if play long, so i reduce it back to 250 khz, why that caps hot?
  Reply With Quote
Old 9th March 2012, 05:35 PM   #1758
norazmi is offline norazmi  Malaysia
diyAudio Member
 
Join Date: Feb 2008
opsss, one more, CPX but in simulation i did parallel 2 pair irf250N , what i can see is mosfet will be more cool and thd is good than 1 pair and it will double the current at output, idk its not clean or not, because its only simulation, but my experience with LTspice it can be trusted st lest +/- 10% accuracy. Imma on the way will do parallel the mosfet with discrete ucd and will report how good they will, let see after i`m back from vacation.
  Reply With Quote
Old 9th March 2012, 06:00 PM   #1759
CPX is offline CPX  Romania
diyAudio Member
 
Join Date: Nov 2004
Location: Cluj
norazmi:

My amplifier will deliver maximum 20A in 1.25 ohm load..so maximum 500 W at 1 khz..it will deliver a little more at 20 hz and much less at 16 kz(around 16A).As i said before i only have +-48 volt suplies.

For eficiency is better to paralel mosfets yes...but that increases complexity and is hard to keep THD low.It is better to use only 2 modern mosfets(irfp4227) than 6 older ones(irf240), but if you want very high continuous rms currents(25A-100A) you will have to use more mosfets to obtain it.

If you make experiments at high currents please post THD and IMD..the "i can hear music so it works" testing is not very convincing for me.

Spice is very good but the result will only be real if you add to the simulation all parasitic factors in your real implrementation,and this is very hard to do...

Have a pleasant vacation!

Last edited by CPX; 9th March 2012 at 06:03 PM.
  Reply With Quote
Old 9th March 2012, 06:11 PM   #1760
Dimonis is offline Dimonis  Russian Federation
diyAudio Member
 
Dimonis's Avatar
 
Join Date: Mar 2011
Location: RF 33 Vladimir
Quote:
Originally Posted by CPX View Post
dimonis:
Yes..i am thinking 300khz...anything lower than 250 khz and the audio band gets too narrow for my taste.

But the people here require kiloWatts , , so the audio band don't mean much to them , only power!
  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 11:06 PM.


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