813 power supply question - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 13th December 2007, 05:24 PM   #1
diyAudio Member
 
Richard Ellis's Avatar
 
Join Date: Sep 2006
Location: Mar del Plata, a BIG seasonal getaway city, can see the Ocean from our residence.
Default 813 power supply question

Ok, here it is my revised 813 triode strapped SE supply.
This is one of many supplies I will need on this project......I just need someone to crunch the math....sin & cosine seem to have evaded me as I haven't used it since long ago........& I can't seem to remember how to punch up the numbers. I have 'Morgans' book & can to all the math EXCEPT this one....looking for the ripple figures. The load this supply will "see" is 90 milliamps per tube, I guess I will need two of these supplies.
Or do I ???
_______________________________________Rick....... ...
Attached Images
File Type: jpg 813 ps two.jpg (39.0 KB, 278 views)
  Reply With Quote
Old 13th December 2007, 06:45 PM   #2
diyAudio Member
 
soundbrigade's Avatar
 
Join Date: Feb 2006
Location: Vaenersborg, Sweden
Send a message via MSN to soundbrigade
Two?? One for each channel?

Have a run with Duncamps PSU Designer: PSUD II .
__________________
/Magnus
  Reply With Quote
Old 13th December 2007, 09:01 PM   #3
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Default Re: 813 power supply question

Quote:
Originally posted by Richard Ellis
Ok, here it is my revised 813 triode strapped SE supply.
This is one of many supplies I will need on this project......I just need someone to crunch the math....sin & cosine seem to have evaded me as I haven't used it since long ago........& I can't seem to remember how to punch up the numbers. I have 'Morgans' book & can to all the math EXCEPT this one....looking for the ripple figures. The load this supply will "see" is 90 milliamps per tube, I guess I will need two of these supplies.
Or do I ???
_______________________________________Rick....... ...

hi,

your input to the bridge is way too high, 2000volts will give you a rectified unloaded 2800 volts dc....

if you use just one half of the secondary it will give you 1400 which is more managable.....but still high....

looks like your transformer is good for one tube, what is the va rating?

__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  Reply With Quote
Old 13th December 2007, 11:26 PM   #4
diyAudio Member
 
Richard Ellis's Avatar
 
Join Date: Sep 2006
Location: Mar del Plata, a BIG seasonal getaway city, can see the Ocean from our residence.
Tony, The spec on the Transformer is one thousand peak RMS!. As you'll recall Peak is 1.41 up on RMS.
So it all translates to nine-hundred or so at the output.
Attached Images
File Type: jpg rectification.jpg (26.8 KB, 156 views)
  Reply With Quote
Old 13th December 2007, 11:45 PM   #5
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Quote:
Originally posted by Richard Ellis
Tony, The spec on the Transformer is one thousand peak RMS!. As you'll recall Peak is 1.41 up on RMS.
So it all translates to nine-hundred or so at the output.
yes, but your schematic as shown has the 1000-0-1000 inputted to the bridge, perhaps you are thinking of full wave centertapped config...in which case you need just 2 diodes and the center tap connected to the minus leg..
__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  Reply With Quote
Old 13th December 2007, 11:46 PM   #6
7N7 is offline 7N7  United Kingdom
diyAudio Member
 
7N7's Avatar
 
Join Date: Jan 2003
Location: England
Yes it's a choke input supply so output voltage is 0.9 and ouput current is x 1.414. Therefore it should be two diodes and centre-tapped as already mentioned.

The operating point you have chosen is pretty good based on my 813 experiences. Actually you should run them at about 900V and 100mA, (4k for SE, 8k for p-p) this was my target when I was messing about with 813

7N7
__________________
Plug them in and light them up
  Reply With Quote
Old 14th December 2007, 04:41 AM   #7
diyAudio Member
 
Richard Ellis's Avatar
 
Join Date: Sep 2006
Location: Mar del Plata, a BIG seasonal getaway city, can see the Ocean from our residence.
OK...I'll concede to the two diodes. The iron is rated at 150 mA at Continuous Commercial Service or CCS. The other rating is 225 mA for Intermittany Commercial or Amauter Service or ICAS.
The upshot is that at a 90 mA draw one TX is fine, but driving both tubes will be a stretch treading on intermittant use/
Has anyone run into this problem of Commercial vs. Amauter ratings?
_______________________________________Rick....... .....
Attached Images
File Type: jpg three.jpg (36.0 KB, 157 views)
  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
Amp power supply question theAnonymous1 Solid State 12 30th August 2008 06:06 AM
Another Power Supply Question soundbadger Tubes / Valves 12 10th October 2007 01:29 AM
Power supply question HugoR Tubes / Valves 9 9th November 2005 09:34 AM
Power supply Question Adam M. Chip Amps 10 4th May 2005 03:19 AM
Power Supply Question RichardJones Tubes / Valves 41 28th April 2003 04:12 PM


New To Site? Need Help?

All times are GMT. The time now is 09:56 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