ucd 25 watts to 1200 watts using 2 mosfets - Page 97 - 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 19th April 2011, 01:45 AM   #961
diyAudio Member
 
Join Date: Apr 2009
Location: In a IRFP4229
Well, that really I can not explain all that well. The only thing is that the way it is connected to the comparator is faster than how it connects normally. But this has the disadvantage of a higher percentage of imbalance and greater amplification still counting. All this was explained by the author here. Amplificador HighEnd Clase D de 25W a 1250Wrms sólo con 2 mosfets N - Página 55 Would translate as much text is here. But that explains the connection of the comparator. And is not unique. Saludos!
__________________
See You On The Other Side
  Reply With Quote
Old 19th April 2011, 07:51 AM   #962
diyAudio Member
 
lorylaci's Avatar
 
Join Date: Aug 2008
Location: Dabas, Hungary
Send a message via MSN to lorylaci
Quote:
Originally Posted by tacatomon View Post
Well, that really I can not explain all that well. The only thing is that the way it is connected to the comparator is faster than how it connects normally. But this has the disadvantage of a higher percentage of imbalance and greater amplification still counting. All this was explained by the author here. Amplificador HighEnd Clase D de 25W a 1250Wrms sólo con 2 mosfets N - Página 55 Would translate as much text is here. But that explains the connection of the comparator. And is not unique. Saludos!
This post is still about offset correction.
To make myself clear I made schemtics. So this is the current connaction of the comparator:
Click the image to open in full size.
As you can see feedback goes to In+, signal is taken from Gnd, and to pin 7 +3V is given. In this connection according to the datasheet, the LM311 has about 1us delay. This delay is higher than any other part in the schematic.

This is the connenction I am talking about:
Click the image to open in full size.
As you can see feedback goes to In-, signal is taken from pin7 (OUT), pin 1 (gnd) is taken to gnd... This is the normal connection of the comparator, according to the datashett it has 200ns delay.
The shorter dealy could help is take the switching frequency higher. In ther original schematic it is about 120-150kHz, which is very low, and causes lot of dissipiation in the output coil. I managed to take it up to 200-250kHz at lower supply voltages, but to take higher we need to shirten the propagation delay.
High propagation delay also limits the maximal modulation limits. So the amp cannot be driven to its supply rails at the output, at about 80-90% modulation it starts to produce modulation error, producing THD. If the prop delay is shorter, thaen the modulation limits can be pushed much higher, so you would need a little smaller rails to produce high power at certain THD.

Tekko was doing experiments, said he pushed the switching freq to 450kHz by this normal connection of the comparator, he published his PCB plan and schematic, but without component values.

I could not be the only one, who is interested in this, this modification can improve the amps perfomance much more.
As I said previosuly DC offset is about a zero problem. If it exists, there are hunderd easy ways to take it away, its a pity job.
__________________
Olyan nem volt még, hogy ne lett volna valahogy
  Reply With Quote
Old 19th April 2011, 03:34 PM   #963
diyAudio Member
 
Join Date: Feb 2007
Location: south of germany
Hi lorylaci,

I tried this in LT-Spice:
Leave the feedback on the positive input of the comparator.
Use a pullup at the output (7), as you have done, take the signal from there.
Connect pin 1 and 4 of the comparator to -3V. (you have pin 1 on gnd).
Swap HIN and LIN of the IR2110.
At least in the simulation it works.
  Reply With Quote
Old 19th April 2011, 06:42 PM   #964
diyAudio Member
 
lorylaci's Avatar
 
Join Date: Aug 2008
Location: Dabas, Hungary
Send a message via MSN to lorylaci
Quote:
Originally Posted by hilli_billi View Post
Hi lorylaci,

I tried this in LT-Spice:
Leave the feedback on the positive input of the comparator.
Use a pullup at the output (7), as you have done, take the signal from there.
Connect pin 1 and 4 of the comparator to -3V. (you have pin 1 on gnd).
Swap HIN and LIN of the IR2110.
At least in the simulation it works.
Yesterday my firend told me the main problem: "you have pin 1 on gnd, so your comp output swings between 0 and 3V, not enoguh to turn on the transistors next to". I put pin 1 to -3V. Now everything works. With some setups my switching frequency reached 400kHz. But now I use the following schematic as a test:
Click the image to open in full size.
The switching freq is at 320kHz (3,1us periodic time). (the same feedback with other connecntiion was at 250kHz)
__________________
Olyan nem volt még, hogy ne lett volna valahogy
  Reply With Quote
Old 21st April 2011, 01:06 AM   #965
diyAudio Member
 
andrewlebon's Avatar
 
Join Date: Feb 2008
Default 1200 Watts

hi
greetings any information on this amp?
Attached Images
File Type: jpg t1200n.jpg (117.1 KB, 1243 views)
  Reply With Quote
Old 21st April 2011, 02:04 AM   #966
diyAudio Member
 
andrewlebon's Avatar
 
Join Date: Feb 2008
Default kit

DIGITCLASS ™:.
1. Set Kitts miniXD Power Amplifier.
- Self assembly kit Kitts.
- Grading of high-quality equipment all.
- Complete set of equipment including heat sink plate bolts, etc. Mika.
Price: 850 Baht

2. Preset to print available miniXD Power Amplifier.
- Power Supply + /-45V to + /-90V power sub + BIAS 12V.
- W is up to 700W @ 4 Ohms, 1200W @ 2 Ohms.
- Of a printed and completed all the test board.
Price: 990 Baht



3. Sheets printed miniXD Power Amplifier.
- Use the print sheet EPOXY FR-4 is already green.
Price: 35 Baht




4. T157-2 core wire thousands of 22uH.
Price: 200 Baht HAS ANYONE TRIED THIS KIT
THANKING YOU
andrew lebon
  Reply With Quote
Old 21st April 2011, 02:53 PM   #967
diyAudio Member
 
andrewlebon's Avatar
 
Join Date: Feb 2008
DIGITCLASS CLASS-D POWER AMPLIFIERS MODULE T2400H.

T2400H SPECIFICATIONS:.
• 400W @ 8 ohms (+ /-90V).
• 750W @ 4 ohms (+ /-90V).
• 1400W @ 2 ohms (+ /-90V).
• 2200W@1.33 ohms (+ /-90V).

• 800W @ 8 ohms (+ /-125V).
• 1500W @ 4 ohms (+ /-125V).
• 2400W @ 2 ohms (+ /-125V).

• Input Impedance: 47k ohms unbalanced.
• Frequency Response: 20 Hz - 20 kHz.
• Supply Voltage: + /-45V to + /-125V.
• BIAS Voltage: 12V to 14V.
• Dimensions (W x H x D): 55 x 45 x 150 mm.
Price: 850.00 Baht


DIGITCLASS ™:.
DIGITCLASS CLASS-D POWER AMPLIFIERS MODULE HyperXD.

HyperXD SPECIFICATIONS:.
• 400W @ 8 ohms.
• 750W @ 4 ohms.
• 1400W @ 2 ohms.
• 2200W@1.33 ohms.
• Minimun load 1 ohm.
• Input Impedance: 100k ohms unbalanced.
• Frequency Response: 20 Hz - 20 kHz.
• Supply Voltage: + /-45V to + /-95V.
• BIAS Voltage: 12V to 14V.
• Dimensions (W x H x D): 55 x 50 x 200 mm.
Price: 1,290.00 Baht

woots:.
Released when offline is very interesting.

Old.
  Reply With Quote
Old 21st April 2011, 08:28 PM   #968
diyAudio Member
 
Join Date: Apr 2010
Location: Nis, Serbia
Can I use IRFP264 for +-90V at 4ohm load?
I want TO247 case and I dont have IRFP4227 or 29 in my country.

Thanks
  Reply With Quote
Old 21st April 2011, 08:45 PM   #969
diyAudio Member
 
lorylaci's Avatar
 
Join Date: Aug 2008
Location: Dabas, Hungary
Send a message via MSN to lorylaci
Of course you can use anything, if there is no other solution, but:
This FET has a very high gate charge. You must use SPadi's idea of the extra transistor helping turn of. It also has very high body diode charge. So this amp won't be so efficient. Care must be needed to avoid cross-conduction too.

I'd reccomend full-bridge design, with lower voltage. At full-bridge you can go up 90-95V, there is no bus pumping (less safety margin is neeed, now you use 250V fet for +-90V).
__________________
Olyan nem volt még, hogy ne lett volna valahogy
  Reply With Quote
Old 22nd April 2011, 12:18 AM   #970
diyAudio Member
 
Join Date: Apr 2010
Location: Nis, Serbia
@ Lorylaci

I bought on the flea market toroid transformer 1500VA 2x62V and 3000VA 2x50V.

First one I wanna use in half bridge but obviously only good transistor for that voltage for 4ohm load is IRFB4227

And second transformer I wanna use in full bridge (IRFB4227) 4 ohm load with good heatsink for my brother disco club but I have to find little toroid core with low Al (for overload protection about what you told me)

Laci, what about your schematic with changes on LM311. Is this good? What if I change 330p to 100-150p and output filter to 20uH with 1uF + IRFB4227 ?

P.s both transformers I bought for 20e from gipsy (probably stolen)
  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 05:25 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