Is PSUD II trust-worthy or not? - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 31st March 2012, 01:02 AM   #1
diyAudio Member
Join Date: Jun 2011
Default Is PSUD II trust-worthy or not?

I was just trying out for the first time the PSUD II and try to make as perfect as possible PS for a tube amplifier i'm making. I was able to find the right combination of caps and resistors and later on added a choke...up to that point no problems at all...the graphic drawing showed me a perfect result. The thing is that when i make an exact replica of already existing and working PS, it gives me totally different readings of voltage on various points in the circuit.
Now, my question is: can i trust PSUD or go for the already proven designs no matter what PSUD shows? Has anyone had positive/negative experience with this PSUD II?

  Reply With Quote
Old 31st March 2012, 01:10 AM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
Zen Mod's Avatar
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
did you use F1 ?
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 31st March 2012, 10:58 AM   #3
DF96 is offline DF96  England
diyAudio Member
Join Date: May 2007
'Exact replica' means you have carefully measured transformer and choke winding resistances and put these in the PSUD2 model, as well as capacitor ESR. You have also adjusted your mains voltage to match the model.

Is 'totally different' an exaggeration?
  Reply With Quote
Old 31st March 2012, 11:41 AM   #4
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
The software user must understand the software workings and be able to check the accuracy of any model predictions.

Looks like you are not safe to be let loose on PSUDII.
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 31st March 2012, 03:49 PM   #5
diyAudio Member
Join Date: Jun 2011
First of all i want to thank you guys for help (seriuosly, not trying to be sarcastic), but as i said i'm new with this software and sure i am doing something wrong, there's no doubt....

I've put as many data available regarding the power transformer, and chokes letting out the ESR of the caps (i will try to get that info too) and by exact replica i ment copying the schematics i have and comparing the results. My question was only (not having any experience with PSUD) if the software was reliable and could be taken as reference...

But i'm not stopping here, i will do further research and eventually find out (i'm actually reading all posts regarding the PSUD) what is the
right way to do it or better what am i doing wrong or missing out!

p.s.: if somebody is interested i can send the copied PSUD file for a check...

  Reply With Quote
Old 31st March 2012, 06:12 PM   #6
DF96 is offline DF96  England
diyAudio Member
Join Date: May 2007
No simulator is perfect, but PSUD2 is reckoned to be quite good. Have you given time for the voltages to stabilise?
  Reply With Quote
Old 31st March 2012, 06:31 PM   #7
Pano is offline Pano  United States
diyAudio Moderator
Pano's Avatar
Join Date: Oct 2004
Location: SW Florida
Blog Entries: 4
Originally Posted by DF96 View Post
Have you given time for the voltages to stabilise?
That's a major mis-step when first learning the software, for sure.
  Reply With Quote
Old 31st March 2012, 08:31 PM   #8
diyAudio Member
Join Date: Jun 2011
@DF96: yes, i've let the voltage to stabilize for 25 seconds (which should be more than enough) and the characteristics on the graphic displayed as flat as a flat can be...with the software i defenitely got the psu right, which to me was too know..get it to work perfectly the first time.... and that's the reason why i tested the software with already proven schematics.
But ok, i'm a lot closer to understand it now, than i was before...
  Reply With Quote
Old 31st March 2012, 10:09 PM   #9
diyAudio Member
zigzagflux's Avatar
Join Date: Oct 2006
Location: Charlotte, NC
You may be best off posting your data file and having us look at it. The software has proven itself to be very accurate time and time again. Typically the issue is either misuse of the features or incorrect input data
  Reply With Quote
Old 31st March 2012, 10:20 PM   #10
diyAudio Member
Loudthud's Avatar
Join Date: Nov 2007
Location: Near Dallas Texas USA
To get accurate results first you must measure the open circuit voltage of your transformer, always higher than the advertised voltage. Also, you need the winding resistance of primary and secondary. You must also set the Mains frequency under options. There is one gray area. When you are using the FWCT configuration, IIRC you need to use half the end to end secondary resistance. I could be wrong on this.

To get accurate results for RMS current, the simulation needs to run an integral number of cycles. 100mS is good because it's 5 cycles at 50Hz, 6 cycles at 60Hz. Use a nice long delay as mentioned above.
  Reply With Quote


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
SimpleSE PSUD II B+ squiffiness Tubelab 19 31st January 2012 02:15 AM
Need help with PSUD II model jrenkin Tubes / Valves 6 14th February 2010 12:12 AM
PSUD II soft start Richard Ellis Tubes / Valves 1 12th November 2009 02:41 AM
Tube tester and PSUD II questions boywonder Equipment & Tools 6 26th August 2008 12:38 AM
PSUD II help Bengali Tubes / Valves 10 15th September 2007 04:58 PM

New To Site? Need Help?

All times are GMT. The time now is 02:52 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2