SSLV1.1 builds & fairy tales - Page 205 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 15th December 2012, 04:14 PM   #2041
diyAudio Member
 
Join Date: Jun 2002
Location: CT
I do. I have oscillations! I should have checked that first.
Lowering R7 makes them worse. The output cap changed to 100uF improves things but only loading the supply down so that 100 mA is shunted by the transistor makes it go away... and then the voltage is stable. I varied the output cap from 47uF to 1800uF and found 1800 to be much worse. 100uF is best.
Here are my choices as I see them:
I can now run the CCS at 500 mA, let my circuit draw 100 mA and add a resistor to draw 300 mA. Then the shunt transistor will dump 100 mA. Or, lower the CCS to 200 mA.
The other option is to build another positive regulator and use it for the negative supply by connecting the positive output to ground. I have all isolated supplies so that will not be a problem.
What do you recommend?
  Reply With Quote
Old 15th December 2012, 05:08 PM   #2042
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
What kind of caps are installed on rails at load side? Since its oscillations with the load, maybe more R value in R7 for damping, or 0.1R in series with the load to buffer it.
  Reply With Quote
Old 15th December 2012, 06:40 PM   #2043
diyAudio Member
 
Join Date: Jun 2002
Location: CT
The oscillations occur with or without the load. I am using just a resistor to simulate the load. My actual circuit that will be the load is currently being built.
The variable seems to be the amount of current through the shunt transistor.
I do not think that buffering the load will help but I will alter the value of R7 and see how that works.
It may be that I need to use all positive regulators to run the amount of current that I want to. That will be a lot more work to do because my heatsink will need to be drilled and tapped for the positive circuit board.
Thanks for your help.
Bill
  Reply With Quote
Old 15th December 2012, 06:45 PM   #2044
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
You talked about varying load and I thought something real. But you did not mean dynamically so. Just changing consumption. Got it. How is it at 200mA spare?
  Reply With Quote
Old 15th December 2012, 08:31 PM   #2045
diyAudio Member
 
Join Date: Jun 2002
Location: CT
Sorry for any confusion. At 200 mA via the shunt transistor it oscillates. I have been checking out my positive regulator with the oscilloscope and it is rock stable at any load.
At this point, I plan to build more positive regulators and use them for the negative power supply. Do you think that there is a problem with that? My transformers and diodes are all separate for the positive and negative side.
Bill
  Reply With Quote
Old 15th December 2012, 08:49 PM   #2046
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
I don't think its that different to the positive. I will have a closer look with the currents you refer and let you know more.
  Reply With Quote
Old 15th December 2012, 08:50 PM   #2047
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
P.S. Are your builds p2p or on PCBs?
  Reply With Quote
Old 15th December 2012, 08:57 PM   #2048
diyAudio Member
 
Join Date: Jun 2002
Location: CT
I am using the circuit boards from tea bag.
One of the FET's has g shorted to d instead of s.
Changing that did not make a difference.
Bill
  Reply With Quote
Old 15th December 2012, 09:20 PM   #2049
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Try 100 Ohm gate stoppers on the 610s.
  Reply With Quote
Old 17th December 2012, 12:54 PM   #2050
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by samoloko View Post
I am looking to buy some films for Vref and Vout
I am struggling between Auricap and Sonicap
would you recommend which can be better to power line aplication - UGS V3
of course you can recommend some other brand
I would like to use Obbligato Gold but It Is so long
There was a builder reporting very favorably for Sonicap there.
  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
GB Thread for Salas SSLV1.1 BiB shunt reg Tea-Bag Group Buys 1464 20th July 2014 01:54 PM
WTB : Salas SSLV1.1 BiB shunt CaNNA3IS Swap Meet 1 24th November 2013 09:43 AM
FS : 2 x Salas SSLV1.1 BiB PCB + 6 x IRF MiniKits korben69 Swap Meet 6 2nd July 2013 09:32 AM
Some VX.2 Builds CSS/XBL CSS 0 11th April 2013 05:34 PM
so who here builds amps amp builder jb Tubes / Valves 29 15th July 2005 08:23 PM


New To Site? Need Help?

All times are GMT. The time now is 12:01 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