150v Mosfet @ 146v? - 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 15th December 2008, 06:23 PM   #11
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
Whoa, I was wrong.

A 2Hz sine was able to drive the rail voltage to almost 90V without the over-current protection tripping.

It fried the 150V MOSFETs I had put in. They were working fine with the normal 73V tail voltage, even with a continuous 20Hz sine at almost full volume.

So this is a real problem, even with unregulated supplies. I don't think it is that big of a concern normally as no one in their right mind would let their woofers oscillate at ~2Hz, let alone at any significant volume.
  Reply With Quote
Old 15th December 2008, 08:58 PM   #12
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
Modify the amplifier, use the low frequency cutoff points from the various coupling capacitors to prevent excessive rail pumping.

Try to find a 200V replacement MOSFET with a fast body diode and low charges, even if it comes in another package, for example IRFB4227.

Paralleling more devices is likely to cause trouble due to the gate charge increase.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 16th December 2008, 02:57 AM   #13
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
I have already decided to go with the IRFP4227PBF.
  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
FS: Sprague Powerlytic 36DX 15000 uF 150V Caps likeafox15 Swap Meet 2 7th December 2010 06:55 AM
150V plate output tubes engels Tubes / Valves 10 10th July 2007 05:01 AM
150v 80Khz piezo driver amplifier Dxvideo Chip Amps 21 14th February 2007 12:58 PM
Looking for PHILIPS 50.000uF/125V and 1.900uF/150V ELCO's pantaNS Parts 1 30th November 2005 07:42 PM
Solid state amp on +/-150V ? DJG Solid State 1 12th March 2003 08:46 PM


New To Site? Need Help?

All times are GMT. The time now is 11:38 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