voltage regulators - diyAudio
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 29th December 2005, 02:33 PM   #1
diyAudio Member
 
Join Date: Feb 2005
Location: Watertown, NY
Default voltage regulators

ok i dont know much about regulated psu's except that they "regulate"
i have a transformer and after rectification puts out +-45VDC i want to bring this down to <80V total. i tried using diodes to lose a few volts (2 per rail) but still +-45VDC. my question is what regulators would be the best to use for such a voltage and to use on a couple OPA541 chips??
  Reply With Quote
Old 29th December 2005, 06:28 PM   #2
mateo88 is offline mateo88  United States
diyAudio Member
 
Join Date: May 2004
Location: Argyle, Texas
The simplest would be lm338's.
  Reply With Quote
Old 29th December 2005, 07:43 PM   #3
diyAudio Member
 
moutoulos's Avatar
 
Join Date: Sep 2005
Location: Patra
Send a message via Skype™ to moutoulos
Οr... like this ...
Attached Images
File Type: png v + - for audio.png (2.9 KB, 614 views)
  Reply With Quote
Old 30th December 2005, 04:49 AM   #4
Wombat2 is offline Wombat2  Australia
diyAudio Member
 
Wombat2's Avatar
 
Join Date: Nov 2003
Location: Brisbane
Lets give credit to Rod Elliottt for the above schematic for his pre reg P102
  Reply With Quote
Old 30th December 2005, 05:47 AM   #5
rodolfo is offline rodolfo  Mexico
diyAudio Member
 
Join Date: Jan 2005
Location: tamaulipas
Quote:
Originally posted by moutoulos
�r... like this ...

r5 10(omegas) ?????
sorry
the eshe.... is ok....only resistor value ????
  Reply With Quote
Old 30th December 2005, 05:53 AM   #6
Keld is offline Keld  Sweden
diyAudio Member
 
Keld's Avatar
 
Join Date: Jan 2002
Location: Borås, Sweden, Tellus
Quote:
Originally posted by rodolfo



r5 10(omegas) ?????
sorry
the eshe.... is ok....only resistor value ????
?????????????

Read more here: http://sound.westhost.com/project102.htm
__________________
"What is done by what is called myself is, I feel, done by something greater than myself in me."
James Clerk Maxwell. 1879
  Reply With Quote
Old 30th December 2005, 06:36 AM   #7
boholm is offline boholm  Denmark
diyAudio Member
 
boholm's Avatar
 
Join Date: Apr 2004
Location: Copenhagen
Default Re: voltage regulators

Quote:
Originally posted by odysseybmx414
i tried using diodes to lose a few volts (2 per rail) but still +-45VDC.

I take it you did not put a load on it? There have to run a current thru' the diodes, before they come with the 0.7 volts. So try and put a load on it and see what happens. 10K 1 W should do it for testing.
__________________
Best regards
Bo
  Reply With Quote
Old 30th December 2005, 08:05 AM   #8
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Is this a possible 4 transistor regulator?

Best if average input voltage is:
1.10 x (Vout + 2)
to account of eventual mains AC 10% drop.

For negative supply transistors are mirrored, NPN to PNP and PNP to NPN.
I have difficult to find out values.
Especially capacitors values.
Values are also much dependent of max output current and amount of ripple at input voltage.
Attached Images
File Type: png reg-discrete2a.png (5.9 KB, 393 views)
__________________
lineup
  Reply With Quote
Old 30th December 2005, 08:26 AM   #9
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
the +-45Vdc is when you have open circuit load.

What is the minimum draw when the circuit is connected?

The open circuit voltage will drop as the load increases and may fall just far enough to lie within the range required. Then your diode drops can be used for final adjustment.
__________________
regards Andrew T.
  Reply With Quote
Old 30th December 2005, 02:51 PM   #10
diyAudio Member
 
Join Date: Feb 2005
Location: Watertown, NY
i connected psu to a opa541 2 channel amp ( one per ch. ) and the voltage dropped to +-41V still too much i played to loud volume and the least voltage i got was +-40V i dont want to take chances on blowing my chips.are you sure the 338's will handle the voltage?
  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
Low Noise 3 Leg Voltage Regulators dsavitsk Parts 2 10th July 2007 02:49 AM
Pre amp voltage regulators help. AMV8 Solid State 19 6th April 2007 09:30 PM
voltage regulators GAK Tubes / Valves 12 25th January 2004 04:34 PM
voltage regulators NAP 160 Digital Source 7 11th August 2002 09:14 PM
Discrete voltage regulators. JoeBob Solid State 1 18th March 2002 05:25 AM


New To Site? Need Help?

All times are GMT. The time now is 12:31 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