Artificial floating ground - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 July 2002, 04:18 PM   #1
diyAudio Member
 
Join Date: Jun 2002
Location: UK
Default Artificial floating ground

Hi All,

This is my first post, so I hope it works ok!

While reading this thread:

much less crazy idea

I noticed the talk of generating floating grounds with big resistors, which reminded of the scheme that Quad used for their 306 amplifer (amongst others, I'm sure). By putting 2 smoothing caps in series, the voltage at their midpoint is roughly equal to half the total supply voltage. To ensure that it remains close to this point, two transistors are used to steer the point to the required voltage. This then forms the signal ground for the whole amplifier.

This arrangement offers DC protection for the loudspeaker - if one of the output devices saturates. the midpoint will be allowed to rise to the appropriate tail, thus avoiding damage to the speaker. The only drawback of this is both capacitors must be rated to the total supply voltage (unlike a conventional split supply, of course)

Hopefully, this might be useful if you happen to have a large mains transformer with a single winding...? Apologies if everyone already knows this!


BTW, click here for the
complete Quad 306 schematic
Attached Images
File Type: jpg quadpsu.jpg (18.8 KB, 470 views)
  Reply With Quote
Old 1st July 2002, 04:36 PM   #2
e96mlo is offline e96mlo  Sweden
diyAudio Member
 
Join Date: Apr 2002
Location: Helsingborg, Sweden
The problem is that this is the same as a capacitor coupled speaker, only the capacitors are placed differently. All the speaker current still have to go through the capacitors and they need to be highly ripple tolerant.

But it is an interesting schematic.

I didn't get the quad link to work, though.

/Marcus
  Reply With Quote
Old 1st July 2002, 05:07 PM   #3
diyAudio Member
 
Join Date: Jun 2002
Location: UK
Sorry about that!

Try this instead

The Quad306 link is towards the end of the list...

I wondered about the sonics, as it does appear to be equivelent to a simple series capacitor at a first glance. But, as the signal is referenced to this floating ground, I guess that feedback should help...
  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
simple HV rail splitter/floating ground - would this work? Rodeodave Power Supplies 3 20th July 2008 04:12 PM
Floating ground power supply Theodore Julie Power Supplies 8 11th June 2007 10:54 PM
Floating Ground Adapter? geek883 Car Audio 2 2nd April 2006 07:26 AM
car preamp with artificial earth(ESP) sagarverma Car Audio 23 8th November 2005 04:31 PM
Artificial Harmonics guitargully Instruments and Amps 1 15th April 2004 06:53 AM


New To Site? Need Help?

All times are GMT. The time now is 07:33 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