
Home  Forums  Rules  Articles  The diyAudio Store  Gallery  Blogs  Register  Donations  FAQ  Calendar  Search  Today's Posts  Mark Forums Read  Search 
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 

Thread Tools  Search this Thread 
25th October 2012, 07:20 AM  #2721  
diyAudio Member
Join Date: Jul 2007

Quote:
guyz the clear pdf artwork for the 4K5 have fun with real tested high power class d 

25th October 2012, 08:24 AM  #2722 
diyAudio Member
Join Date: Dec 2003
Location: Nottingham UK

An ETD29 core with a 1mm gap in the centre leg only will have an inductance factor (Al) of close to 125nH.
The equation for the total inductance (where N is the number of turns) is N^2 * Al. So 17 turns will give you roughly 35uH. If you are adding a 1mm gap to an ungapped core set (so the gap is in all legs), the Al will be much lower of course. 
25th October 2012, 12:29 PM  #2723  
diyAudio Member
Join Date: Jul 2007

Quote:
so gap in all legs it will come to how many turns to make 35uh Last edited by stewin; 25th October 2012 at 12:52 PM. 

25th October 2012, 12:57 PM  #2724 
diyAudio Member
Join Date: Dec 2003
Location: Nottingham UK

It is not a parameter that is defined in the data for the cores. This is the time to buy a low cost inductance meter perhaps?
When I get an unknown core, I wind a known number of turns on, measure the inductance and then determine Al. I then can use this value to calculate the mumber of turns needed for any required inductance on that particular core. 
25th October 2012, 01:01 PM  #2725 
diyAudio Member
Join Date: Jul 2012
Location: goianesiagoias


25th October 2012, 02:52 PM  #2726 
diyAudio Member
Join Date: Oct 2009

irs 3000 coil inductance(uh) ?

25th October 2012, 03:02 PM  #2727 
diyAudio Member
Join Date: Aug 2008

Hi stewin,
i used 40T .85mm core 1mm gap all (@70uH) fsw=250KHz cap=2.5uF/250V, cool quite MOSFET IRFP250N with resistor 39 Ohm. Regards MANOJ 
25th October 2012, 03:36 PM  #2728  
diyAudio Member
Join Date: Aug 2008

Quote:
use 28T for 35uH regards MANOJ 

25th October 2012, 04:58 PM  #2729 
diyAudio Member
Join Date: Jul 2007


25th October 2012, 07:07 PM  #2730 
diyAudio Member
Join Date: Jul 2007

the component side side of pcb
thanks to ht forum Amplificador ClasseD  Página 74 have all the fun with high power amps " seek and you shall find " Last edited by stewin; 25th October 2012 at 07:14 PM. 
Thread Tools  Search this Thread 


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Philips 40/25/15 watts amplifier with Universal preamplifier circuit.  renjiish  Solid State  55  4th April 2014 07:08 AM 
Decibel Watts VS Watts ?  fivestring  Solid State  11  1st April 2009 01:08 PM 
AMP1B: 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? 