Bridge amp feedback
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 4th April 2003, 05:18 PM #1 sangram   diyAudio Member   Join Date: Sep 2002 Location: India Bridge amp feedback Hi Pulled this out of a datasheet. Why are the values of the NFB resistor different in the two halves of the amp? I assume there is a quality buffer before the power amp (which this is), and the circuit below is used. Why is one having a gain of 20, and the other 21? Or is it for impedance compensation?
sangram
diyAudio Member

Join Date: Sep 2002
Location: India
Oops:

Attachment
Attached Images
 1.jpg (27.3 KB, 232 views)

 4th April 2003, 05:40 PM #3 rljones   diyAudio Member   Join Date: Mar 2001 Location: california Because one op-amp is inverting and the other is non-inverting.
 4th April 2003, 05:44 PM #4 Andypairo   diyAudio Member     Join Date: Sep 2002 Location: near Milano , Italy Inverting gain is Rfb/Ri, non-inverting gain is 1+Rfb/Ri. Cheers Andrea
 5th April 2003, 08:03 AM #5 sangram   diyAudio Member   Join Date: Sep 2002 Location: India Thanks for clearing that up.
 5th April 2003, 09:16 AM #6 Elso Kwak   Banned   Join Date: Dec 2001 Location: Zamboanga, City of Flowers, Mindanao Gain Hi, Isn't Vo= (1+ Rfb/Ri) Vi (noninverting) Vo= outputvoltage Vi = inputvoltage So the noninverting gain is Vo/Vi= 1+ Rfb/Ri and the inverting gain is - Rfb/Ri (assuming zero source impedance)
sangram
diyAudio Member

Join Date: Sep 2002
Location: India
Re: Gain

Quote:
 Originally posted by Andypairo Inverting gain is Rfb/Ri, non-inverting gain is 1+Rfb/Ri. Cheers Andrea

Quote:
 Originally posted by Elso Kwak ... So the noninverting gain is Vo/Vi= 1+ Rfb/Ri and the inverting gain is - Rfb/Ri (assuming zero source impedance)
Yes, I guess, whatever, but both above look the same to me (with the exception of the (-) sign in Elso's ) ??

 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 Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post dcmdcm Class D 3 2nd June 2007 07:20 PM digi01 Chip Amps 0 8th September 2006 03:10 AM -_nando-_ Chip Amps 3 17th May 2006 07:22 AM fr0st Class D 6 9th December 2004 03:15 PM

 New To Site? Need Help?

All times are GMT. The time now is 04:47 AM.