PSUDII simulation vs reality - 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 22nd May 2012, 09:20 AM   #1
diyAudio Member
 
Join Date: Mar 2012
Default PSUDII simulation vs reality

I have a tube rectified LC-LC-LC power supply that I designed with PSUDII. I took care to use have enough resistance and large enough capacitor to avoid the initial voltage spike. Not only I do get the spike, I get a pretty big one (upto 180+V, takes a few seconds to stabilise to 100+V).

I was told that the initial spike can be an indication that the PSU would ring.

I wonder if it is normal? Or is there something wrong? The chokes I used are pretty cheap. And the tube rectifier heater is starved (5.4V instead of 6.3V) and probably because of that I also get quite a bit lower output than simulated.
  Reply With Quote
Old 22nd May 2012, 10:06 AM   #2
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
PSUs with chokes can ring. Difficult to say more than that without a circuit diagram.
  Reply With Quote
Old 22nd May 2012, 10:54 AM   #3
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
zip and attach PSUD file here
__________________
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 22nd May 2012, 03:19 PM   #4
diyAudio Member
 
Join Date: Mar 2012
Here it goes.

I put the first choke as 1083 ohms, it is actually 250 ohms with 833 ohms worth of resistor in series.

The last cap of 80uF is made up of 2x40uF in parallel.
Attached Files
File Type: zip B+ Supply.zip (278 Bytes, 41 views)
  Reply With Quote
Old 22nd May 2012, 04:14 PM   #5
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Sorry, my PSUD2 won't open it.
  Reply With Quote
Old 22nd May 2012, 04:37 PM   #6
diyAudio Member
 
Join Date: Mar 2012
This is how it looks like.

Click the image to open in full size.
  Reply With Quote
Old 22nd May 2012, 04:43 PM   #7
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
So L1 really has that high of a DCR?

To check stability, use a CCS as the load, set to the expected current for the intended load. Then use the "step" option to have it step up or down by (say) 20% after 10 seconds or so. See what happens.
__________________
And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
  Reply With Quote
Old 22nd May 2012, 04:57 PM   #8
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
I suspect what is happening is that the LC filtering means that the initial choke input stage sees very little current draw at first, so its voltage shoots up. Once things stabilise it does what you expect. You won't see any spike on the output with PSUD2 because your load in the simulation draws current straight away. Plot V(C1) to see a spike (my prediction - I could be wrong).
  Reply With Quote
Old 22nd May 2012, 05:19 PM   #9
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
C1 and C2 and C3 ensure that the first L sees a substantial current load from start up.
That should prevent a spike due to the L not seeing a significant current load for choke input to operate as expected.
__________________
regards Andrew T.
  Reply With Quote
Old 22nd May 2012, 05:23 PM   #10
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by SY View Post
So L1 really has that high of a DCR?

To check stability, use a CCS as the load, set to the expected current for the intended load. Then use the "step" option to have it step up or down by (say) 20% after 10 seconds or so. See what happens.
Before L1 I put a bunch of resistors in series to cut down the voltage to where I need it, I lumped the total resistance together with L1.

The load is set as CCS. I tried stepping up or down, they look smooth, no spikes.
  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
Tapped Horns - Simulation VS Reality Patrick Bateman Subwoofers 59 28th December 2011 02:49 AM
PSUDII Question Captn Dave Tubes / Valves 11 2nd March 2011 05:54 PM
PSUDII transformer question rotaspec Tubes / Valves 13 25th March 2010 06:58 PM
hybrid graetz in PSUDII JoshK Tubes / Valves 1 27th January 2007 02:50 AM
Your thoughts on simulation compared to reality Mr Evil Everything Else 12 1st March 2005 04:45 AM


New To Site? Need Help?

All times are GMT. The time now is 07:10 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