Hall-effect current sensor for output stage over-current protection - 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 2nd September 2011, 07:47 AM   #1
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
Default Hall-effect current sensor for output stage over-current protection

I am considering to use a hall-effect current sensor such as ACS-712 (http://www.allegromicro.com/en/Produ.../0712/0712.pdf) to protect amplifier output stage. The resistance of the copper conductive path of ACS712 is just 1.2 mR which is effective zero resistance in the intended application. It is also electrically isolated from other part of the chip. The output analog signal can be used to drive a relay circuit or sampled by ADC of an MCU.

Since the conductive path is just a piece of copper, it should not introduce any distortion. Although the chip employes chopper stabilization technique, the electrically isolated path should not be picking up any interference. Well, it might via capacitive or inductive paths.

Any comment?
  Reply With Quote
Old 2nd September 2011, 05:21 PM   #2
cbdb is offline cbdb  Canada
diyAudio Member
 
Join Date: Oct 2008
Location: Vancouver
Looks like a great idea.

Quote:
Well, it might via capacitive or inductive paths.
But probably no worse than any other technique.
  Reply With Quote
Old 2nd September 2011, 05:57 PM   #3
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
More than ten years ago I did similar current sense-protection, adjustable to any current-trigger level as needed. It works perfectly till these days.
Attached Images
File Type: jpg AMP PROT.jpg (353.0 KB, 136 views)
  Reply With Quote
Old 2nd September 2011, 08:03 PM   #4
Spiny is offline Spiny  United Kingdom
diyAudio Member
 
Spiny's Avatar
 
Join Date: Feb 2008
I posted one a while back, Still in daily use
hall effect dc speaker protection
  Reply With Quote
Old 6th September 2011, 03:07 PM   #5
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
Lazy Cat and Spiny,

Yes, I visited your thread.

I plan do all the things in an MCU which samples Vce, temperature, etc. Transistor SOA parameters can be input to the firmware. Temperature data can be used for derating.
  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
Hall Effect DC Speaker protection Spiny Everything Else 2 9th January 2010 04:55 PM
Current Sensor based on OpAmp mahmood Power Supplies 4 26th September 2008 05:08 PM
UcD output stage current sensing zilog Class D 20 6th November 2006 08:04 AM
Floating current source in cascoded output stage rtarbell Pass Labs 0 7th April 2006 01:46 AM
Over-current protection in Audio IC Output Buffers ppl Solid State 1 21st October 2003 06:35 AM


New To Site? Need Help?

All times are GMT. The time now is 11:14 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