Help with regulated +/- 15V PSU schematic - Page 2 - 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 6th November 2004, 02:42 AM   #11
maxw is offline maxw  United Kingdom
diyAudio Member
 
maxw's Avatar
 
Join Date: Jun 2004
Location: London
Quote:
Originally posted by jackinnj
This design will cost less and handle more current
I am probably wrong but does this mean it will supply 100mA maximum:
"Sink-Current Capability . . . 1 mA to 100 mA"

If so, that is 10x less than the above regulators. I can see that it is a better design but it would cost me more as I would have to order the TL431 from RS components which will cost at least $10 for 2.
I am still not ruling it out though.
What function do the MJE1503x perform? why is it needed so high volts and amps? (150V 8A)?
  Reply With Quote
Old 6th November 2004, 02:59 AM   #12
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally posted by maxw


I am probably wrong but does this mean it will supply 100mA maximum:
"Sink-Current Capability . . . 1 mA to 100 mA"

Those aux transistors do the heavy lifting -- the TL431's supply a reference to the base of the Pass transistors. I use the ones shown in the schematic since I have hundreds of them in stock at my webstore. You can use whatever suits your fancy. The ratio of the two voltage divider resistors differs between the positive and negative supplies.

The LT1761 and LT1964 really aren't necessary unless you need power supply noise in the microvolts -- I just used them in a project from which the schematic is lifted -- they will only handle 100ma or so.

The protocol on DIYAUDIO, one which I respect, is not to flog your stuff, so if you are interested in parts email me privately. I have circuit boards too.
  Reply With Quote
Old 6th November 2004, 04:05 AM   #13
maxw is offline maxw  United Kingdom
diyAudio Member
 
maxw's Avatar
 
Join Date: Jun 2004
Location: London
Quote:
Originally posted by jackinnj



Those aux transistors do the heavy lifting -- the TL431's supply a reference to the base of the Pass transistors. I use the ones shown in the schematic since I have hundreds of them in stock at my webstore. You can use whatever suits your fancy. The ratio of the two voltage divider resistors differs between the positive and negative supplies.

The LT1761 and LT1964 really aren't necessary unless you need power supply noise in the microvolts -- I just used them in a project from which the schematic is lifted -- they will only handle 100ma or so.

The protocol on DIYAUDIO, one which I respect, is not to flog your stuff, so if you are interested in parts email me privately. I have circuit boards too.
Thanks jackinnj
I'll have a think about this as I have many options now
I enjoy making my own PCBs and the fact you are all the way in the USA rules out getting any parts from there anyway due to postage costs.
  Reply With Quote
Old 6th November 2004, 04:59 AM   #14
maxw is offline maxw  United Kingdom
diyAudio Member
 
maxw's Avatar
 
Join Date: Jun 2004
Location: London
Quote:
Originally posted by jackinnj



Those aux transistors do the heavy lifting -- the TL431's supply a reference to the base of the Pass transistors. I use the ones shown in the schematic since I have hundreds of them in stock at my webstore. You can use whatever suits your fancy. The ratio of the two voltage divider resistors differs between the positive and negative supplies.
Could you use cheap small transisters intsead of the MJE1503x?

eg. BC338 and BC328? if not can you recommend a smaller transister that is more readily available than MJE1503x?

So this design would provide less noise than the design above or an LM317 based PSU?
  Reply With Quote
Old 6th November 2004, 11:17 AM   #15
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
Quote:
Originally posted by maxw
I have reversed the ones that are by the regulators.
Look on picture below.

Quote:
Question: The regulators will supply 1A on each rail, will have to use resisters that are more that 1/4W to draw 1A off of each rail?
Use Ohms law:
P=I x I x R

Regards,
Milan
Attached Images
File Type: jpg 03250.jpg (24.5 KB, 580 views)
  Reply With Quote
Old 13th November 2004, 05:34 AM   #16
lopan is offline lopan  United States
diyAudio Member
 
Join Date: Sep 2004
Location: California
Default 7815

A little off the path sorry but I hopw not too far. Seems like the expertise I need is here.


If I tie a 15 or 16 volt source to the output pin of an umpowered 7815 and 0 to its ground pin will this damage it. I want to be able to jump back an forth between two supplies -- one on board and the other outboard.

Any thoughts thanks
  Reply With Quote
Old 27th November 2004, 01:39 AM   #17
maxw is offline maxw  United Kingdom
diyAudio Member
 
maxw's Avatar
 
Join Date: Jun 2004
Location: London
I made a new one with LM317/LM337 as its simple and lower noise the the 79xx regs I had at first:

Click the image to open in full size.

Click the image to open in full size.

  Reply With Quote
Old 27th November 2004, 08:07 AM   #18
lopan is offline lopan  United States
diyAudio Member
 
Join Date: Sep 2004
Location: California
Looks sweet.

Are D1 and D2 for start up to make sure the output is not more than a diode below the input?
  Reply With Quote
Old 27th November 2004, 08:36 AM   #19
maxw is offline maxw  United Kingdom
diyAudio Member
 
maxw's Avatar
 
Join Date: Jun 2004
Location: London
Quote:
Originally posted by lopan
Looks sweet.

Are D1 and D2 for start up to make sure the output is not more than a diode below the input?
"These diodes protect the regulator when the caps on the OUT and ADJ pins discharge" - quote from http://tangentsoft.net/elec/teps/pguide.html which was one of the schematics I based mine on
  Reply With Quote
Old 27th November 2004, 09:13 AM   #20
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
To be more precise: If the smoothing caps are small and you for some reason has additional smoothing on the regulated side...and the discharge time is longer in the regulated side than the unregulated, then you need these diodes but normally you don't, espcelly if you have known loads but if you are going to make a general power supply you should have these diodes, just in case. They are for protection purposes only.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  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
TL783 regulated B+ 250V PSU schematic eranrund Tubes / Valves 40 29th June 2009 08:47 AM
5V out of 12V regulated DECKY999 Power Supplies 0 7th April 2008 05:37 AM
Regulated or non-regulated SMPS longitude Class D 5 8th May 2007 03:02 PM
Regulated PSU Help.. jleaman Analogue Source 9 26th July 2004 12:36 PM


New To Site? Need Help?

All times are GMT. The time now is 02:28 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