Help needed for constant current source design. - 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 7th July 2012, 10:08 PM   #1
diyAudio Member
 
Join Date: May 2010
Location: mumbai(India)
Question Help needed for constant current source design.

I want to design constant current source for audio amp.but i dont know how to calculate value of resistor for required current.l have attached constant current source circuit here.So anyone please give me formula & calculation for this.
Attached Images
File Type: jpg Ccs .jpg (235.6 KB, 182 views)
  Reply With Quote
Old 7th July 2012, 10:27 PM   #2
Vostro is offline Vostro  South Africa
diyAudio Member
 
Vostro's Avatar
 
Join Date: May 2012
Location: Other side of the fence
Current Sources, Sinks and Mirrors in Audio is a start.

Regards
  Reply With Quote
Old 7th July 2012, 10:33 PM   #3
DUG is offline DUG  Canada
diyAudio Member
 
Join Date: Jan 2003
Location: mississauga ontario canada
To get you in the ballpark let's make some assumptions

Hfe of transistors is >= 100 at operating current

left transistor we will call Q1 the other Q2

current for Q2 will be close to (35-1.2) / R2

find the Vbe for Q2 at that current

I will be Vbe / R1

This will get you within a couple of % of what you need.

one more assumption: Q1 can handle the power dissipation and the SOA for your requirements

If Hfe is not that high you will have to look at current paths and do some adding and subtracting

hope that helps
__________________
Doug We are all learning...we can all help
"You can't stop the signal, Mal. Everything goes somewhere..."
  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
constant current source tubem Pass Labs 26 4th September 2011 11:48 AM
Why is it not a Constant Current Source ? payloadde Power Supplies 3 17th April 2011 10:59 PM
How do I design a pentode constant current source plate load? Bitrex Tubes / Valves 16 22nd January 2009 09:10 AM
constant current source hacknet Solid State 19 13th March 2006 03:46 PM


New To Site? Need Help?

All times are GMT. The time now is 04:43 PM.


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