Help with SMPS - 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
Closed Thread
 
Thread Tools Search this Thread
Old 21st September 2012, 02:28 PM   #1
diyAudio Member
 
Join Date: Aug 2012
Default Help with SMPS

I am trying to build this half bridge SMPS, modified/improved PC design, operating from 230V AC providing about 13.8V DC with MOSFET rectifiers. Operates at 50kHz.
250 W S.M.P.S. with Power-FETs James Arthur
1. There is a snubber of 2.2nF / 100 Ohms across the primary winding. The resistor wattage is given as 2W. I tried calculating the wattage, as
50000 X 4 X (CV^2) / 2, as there are 4 transitions per cycle, with V taken as 190V, half of peak voltage, at input high 230*1.15*1.414. With that I am getting a Pd of around 6W.
2. There is a snubber of 10nF / 10 Ohms across the secondary. Here also the resistor is specified as 2W, but my calculation like the above, with a secondary peak voltage of 33.25 X 2, gives a Pd of 4.4W! Am I making a missing something or my snubber calculation is wrong?
3. Can I use a still lower RdsOn MOSFET like 2.2 mOhm NXP PSMN2R0-60PS,127 instead of the IRFZ44 used in the original schematic, for output rectification to improve efficiency further? Will those parameters like, higher gate charge, capacitance matter?

Thanks in advance.
 
Old 21st September 2012, 08:20 PM   #2
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007


Non isolated supplies of this kind are potentially lethal and are against the forum rules.

Thread closed.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
 

Closed Thread


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
Linn "LINTO" MC Preamp Schematic without SMPS - Schematic for SMPS wanted tiefbassuebertr Analogue Source 40 14th July 2014 08:10 AM
Smps a2005r2003 Power Supplies 19 11th August 2011 06:19 AM
Is this really an SMPS? TylerDurden Power Supplies 9 14th July 2011 11:03 AM
Smps rinox Power Supplies 0 2nd September 2005 10:05 PM
Smps hugefathead Solid State 8 5th March 2004 03:44 AM


New To Site? Need Help?

All times are GMT. The time now is 09:18 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