Pre-clipping as a method of power regulation - 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 1st May 2008, 07:18 AM   #1
diyAudio Member
 
Join Date: Oct 2004
Default Pre-clipping as a method of power regulation

Since most of my experience is in the 12V field, I'll center the idea there. I suppose this applies to any design, though.

For whatever reason, some designs regulate the power output of a class-D amplifier (doesn't apply to a/b). This is always done by regulating the secondary voltage, and running the output stage into saturation. Pre-clipping the output signal at some point would have roughly the same effect, and would greatly simplify power supply.

The output stage would have to be more robust, especially when the goal is to make full power into a range of output impedances. This cost, however, has to be paid anyway, be it in the power supply, or the output stage. I've done the math, it's definitely less efficient to regulate the secondary DC voltage than the output signal. Many of the problems associated with hard clipping are also eliminated.

I've finally found enough time to build a UcD for a car. I've built many different car PS in the past, even had a 1.5kW Weinberg at one time, but never had much luck with regulated supplies. At low frequencies, the output inductor is huge. At high frequencies, the leakage inductance of the xfmr eats your lunch. In either case, high line = low duty cycle = lots of loss everywhere = bad news. Just seems that running a simple chopper, and limiting the output swing is easy to implement, and can be adjusted on the fly faster than you can say compressor-limiter.

Any thoughts? I'll definitely post my progress here.
  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
gainclone power supply regulation cryo Chip Amps 6 23rd April 2008 03:56 PM
“Ideal” power/regulation for higher-current digital-section ICs hollowman Digital Source 0 8th April 2008 05:07 AM
LM317 for power amp regulation? skyraider Tubes / Valves 32 10th June 2005 02:19 PM
SET Power Supply Regulation serengetiplains Tubes / Valves 33 19th May 2004 12:12 AM
Midcable Power Regulation arnach Everything Else 0 16th February 2002 11:01 PM


New To Site? Need Help?

All times are GMT. The time now is 06:46 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