clean psu design attempt - 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 5th September 2005, 10:51 AM   #1
m0nty is offline m0nty  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: near Venice
Send a message via MSN to m0nty
Default clean psu design attempt

hi

i've build an headphone amplifier (http://headwize.com/projects/showfil...szeke1_prj.htm). It's a class A amp, i'm now shure about the power consuption, but **should** be less than 10W (2 chan).

now, since it is very sensible to the power supply quality, i decided to build myself one to get rid oh the hum

i tried to design it myself, basically it's a transformer+recitifier bridge and filter, followed by an lm317 regulator (as taken from the datasheet), a capacitance multiplier (http://sound.westhost.com/project15.htm) to reduce ripple and a couple of capacitors for energy reserve

the schematic is attached

i'd like to build a nice unit, with a voltmeter panel on the front, and regulate the voltage with a pot (R1, under the lm317), so I can use it for different projects
i'd like to have from +12V to about +20V on the load

now i need help with calculations, here's what i did:

from the datasheets of lm317:
to have high current out (typ 2.2A), Vin-Vout <= 15V
for the lm317 to work, Vin-Vout >= 3V, let's have 4V
so, 4 < Vin-Vout < 15

now i want 12<Vout<20 (i know i loose something on the capacitance multiplier, but i'll survive ...)

4 < Vin - 12 < 15 => 16 < Vin < 27
4 < Vin - 20 < 15 => 24 < Vin < 35
the most restrictive are
*** 24 < Vin < 27 ****

let's have 25V ...
to have this, i need a transformer with 25 / sqrt(2) = 17.67V
=> the transformer should be a 18V


is all this right???
are there any big errors on the schematic?

dc output shouldn't be more than 20V @ 1A, so, considering losses in the psu, how many VA should the transformer be?

i've never designed a psu before, so I just combined different elements and did some math ...

please help
thanks in advance

Nicola
Attached Files
File Type: pdf psu.pdf (20.7 KB, 97 views)
  Reply With Quote
Old 5th September 2005, 10:54 AM   #2
m0nty is offline m0nty  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: near Venice
Send a message via MSN to m0nty
i forgot ...
for the transistor in the capacitance multiplier section, what should I get? the article in sound.westhost.com suggests a darlington ...
what models are easily reperible out there?
thanks
  Reply With Quote
Old 6th September 2005, 06:55 AM   #3
m0nty is offline m0nty  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: near Venice
Send a message via MSN to m0nty
bump ...
  Reply With Quote
Old 6th September 2005, 07:32 PM   #4
rinox is offline rinox  Italy
diyAudio Member
 
Join Date: Oct 2004
Hi... paesÓ
You can find a simplified version of the PSU in this page Clicca qui

Spero di essere stato d' aiuto
  Reply With Quote
Old 7th September 2005, 06:27 AM   #5
m0nty is offline m0nty  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: near Venice
Send a message via MSN to m0nty
grazie ...
comunque ho provato con lo spice, e ho visto che ha tempi di carica piuttosto alti ... per adesso vado solo con il regolatore, poi vedr˛
ciao
  Reply With Quote
Old 7th September 2005, 07:08 AM   #6
Ipanema is offline Ipanema  Malaysia
diyAudio Member
 
Ipanema's Avatar
 
Join Date: Jun 2004
Location: KL
Hi,

Is it possible to replace BD139/TIP3055 with TIP142 and BD140/TIP2955 with TIP147?

Thanks.
  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
The "Freebird" ultra clean ultra simple preamp design Russ White Chip Amps 87 11th August 2008 09:28 AM
6V6 guitar amp design attempt Craig405 Tubes / Valves 29 2nd August 2006 04:48 PM
Requesting critique on my 2nd PCB design attempt adolphe Parts 1 10th June 2006 03:12 PM
My first attempt at amp design VEC7OR Solid State 7 28th August 2005 01:50 AM
Clean Sheet: Pls recc an existing design w/ parts avail in Australia fishball79 Multi-Way 18 3rd March 2004 10:14 PM


New To Site? Need Help?

All times are GMT. The time now is 08:49 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ę1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2