Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 22nd October 2003, 11:18 AM   #1
diyAudio Member
 
Join Date: Sep 2003
Location: Illinois
Default Parrallel / Bridge amp

I found this schematic at the following site:

http://www.euronet.nl/~mgw/diy/amps/...inclone_1.html

and was wondering how to bridge it. The site just said to build 2 and bridge them. Anotherwords does that mean to just connect the gnd on the speaker to the second amps output, and remove the input connector on the second amp?

Also, the schematic uses a LM3875. What would be better in this application? A 3875 or a 3886? Also, how much voltage and amperage be needed for this circuit. I have a transformer that puts out 48VCT, and somewhere below 4A. I am not sure of the measurement, but I will check. It came from the surplus store unmarked, and since it doesn't blow my rectifier, it mush be under 4A.


Thanks, Mike
Attached Images
File Type: gif chainclone_inverted_parallel.gif (3.4 KB, 337 views)
  Reply With Quote
Old 22nd October 2003, 11:30 AM   #2
Paulr is offline Paulr  United Kingdom
diyAudio Member
 
Join Date: Nov 2002
Location: S.Yorks, UK
Default AN1192

Have a look at the application note AN1192 at National Semi

http://www.national.com/an/AN/AN-1192.pdf

Its got all the basics & theory you will need to get started

Cheers

Paul
  Reply With Quote
Old 22nd October 2003, 06:26 PM   #3
macboy is offline macboy  Canada
diyAudio Member
 
Join Date: Oct 2003
Location: Ottawa, Canada
You need to go back to that site and note that there are two different configurations shown: one is inverting (the one shown in your attachment) and the other is non-inverting. What you need to do is build one of each of these, then connect the speaker between the output of the inverting one and the output of the non-inverting one. What you will have done is bridged together two amps, each of which is itself a parallel amp. The effective load is the same as for a single amp device running normally, but since you are using four of them, you get about 4 times the total output power for a given load (speaker).

You can use either the 3875 or the 3886, but note that the 3875 is better suited to 8 ohm loads, and the 3886 is better suited to 4 ohm loads. So the choice of amp device will be based on what speaker you plan to drive with this amp. The desired + and - rail voltages, and the current required, will also depend on the speaker (it will be a lower voltage but higher current for a 4 ohm than for a 8 ohm speaker).

Take a look at this page at National to see the output power of their various amp chips for 4 and 8 ohm loads. Also take a look at this application note at National, which describes how to make bridged, parallel, and bridged-parallel amplifiers.
  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
bridge or parrallel subamp help HIPCHECK Chip Amps 5 13th October 2006 10:00 PM
TDA7293v Parrallel / Bridge Application Theory and Concepts SuperAudioBuff Chip Amps 3 14th February 2005 09:43 AM
parrallel or series nOOSE Multi-Way 6 8th October 2004 07:36 AM
Bridge and Parrallel Output Resistors. Matttcattt Chip Amps 4 15th February 2004 10:35 PM
Bridge/parrallel amp from Ic's (200W) partyjups Solid State 10 7th August 2001 07:40 AM


New To Site? Need Help?

All times are GMT. The time now is 02:58 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