Poles and zeros for two transistor forward? - 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 26th September 2012, 05:23 AM   #1
treez is offline treez  United Kingdom
Banned
 
Join Date: Sep 2012
Default Poles and zeros for two transistor forward?

Hello,

Can any reader list the poles and zeros for a two transistor forward converter?

i.e. for the power stage and modulator?

The control chip is UCC38C44
http://www.ti.com/lit/ds/symlink/ucc38c44.pdf

Vin = 385VDC
Vout = 80V
Load = 20 Ohms (maximum, heavyest load)
Switching frequency = 85KHz
C(out) = 940uF
ESR of Cout = 0.1 Ohm
L(out) = 186uH
Turns ratio (Ns/Np) = 46/50
Current sense resistor = 0.15 Ohms
Continuous conduction Mode.
Duty cycle at max load (20R) = 0.24



...its for Class B amp supply. (output is actually +/-40V, but lets call it 80V...i hope thats OK?
  Reply With Quote
Old 26th September 2012, 06:37 AM   #2
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
It's over my head but TI has a free downloadable spice simulator for it's own products that will do this for you, called Tina.

jan didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W S Maugham
Check out Linear Audio!
  Reply With Quote
Old 26th September 2012, 08:22 AM   #3
diyAudio Member
 
darkfenriz's Avatar
 
Join Date: Jun 2004
Location: Warsaw
Current loop: pole at Rsense and (Lout/turns ratio) i.e. R/2piL
Voltage loop: pole at Cout Rload i.e. 1/2piRC, zero at Cout ESR i.e. 1/(2*pi*ESR*C)
no tricks here.

Last edited by darkfenriz; 26th September 2012 at 08:32 AM. Reason: mistake
  Reply With Quote
Old 26th September 2012, 02:40 PM   #4
diyAudio Member
 
Join Date: Mar 2008
yes. and given that Treez cant play with the current loop at all, might as well pretend its perfect, and treat the entire power stage as a transconductance. gm = delta_Iout/delta_Vcomp. thats pretty easy to work out - but dont forget the x1/3 from Vcomp to Vcurrentsense
  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
Poles and throws? MagnumOpus Analog Line Level 17 17th April 2012 10:36 AM
Poles or feedback 101 tvrgeek The Lounge 9 16th January 2012 01:51 PM
correct # of poles source selector? h_a Solid State 2 6th February 2007 09:28 AM
Best source of ones and zeros? tmd1 Digital Source 16 29th September 2003 10:12 PM
Ones and zeros recorded on CDs chris ma Digital Source 60 25th March 2003 09:46 AM


New To Site? Need Help?

All times are GMT. The time now is 01:17 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