a 5ar4 problem - Page 2 - 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 February 2005, 05:21 PM   #11
Giaime is offline Giaime  Italy
diyAudio Member
 
Giaime's Avatar
 
Join Date: Oct 2004
Send a message via MSN to Giaime
He said he didn't have a 5v winding. I suggest to install a small transformer for the rectifier heater. A small 6V trafo will sag quite a bit when supplying an heater, so the voltage will drop to about 5 volts.
  Reply With Quote
Old 14th February 2005, 01:44 AM   #12
diyAudio Member
 
Join Date: Aug 2003
Location: Indiana USA
Quote:
its not clear from you schematic. I'm assuming that the ht transformer is centre tapped
No, as shown in the picture it doesn't have any center tap. I am thinking about giving up tube rectifiers. That is.
Lhchen
__________________
The best way to stop rust on transformers is to power them up.
  Reply With Quote
Old 14th February 2005, 01:46 AM   #13
diyAudio Member
 
Join Date: Aug 2003
Location: Indiana USA
Quote:
What is the peak reverse voltage of that bridge recifier? You are probably exceeding it terribly...my guess.......
I think 530vac is not a problem for 5ar4.
Thanks for replying.
Lhchen
__________________
The best way to stop rust on transformers is to power them up.
  Reply With Quote
Old 14th February 2005, 02:51 AM   #14
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by contaxchen
[No, as shown in the picture it doesn't have any center tap. I am thinking about giving up tube rectifiers.
Without a centre tap that circuit won't work... you'd need to use both rectifiers to make a full wave bridge.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 14th February 2005, 03:16 AM   #15
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
Planet 10 is right, there is no current path through your circuit. But even if you get that right, until you put a filter cap on the output it will still measure high voltage AC since the rectified waveform is a steady stream of half sinewaves.
  Reply With Quote
Old 14th February 2005, 03:52 AM   #16
diyAudio Member
 
Join Date: Aug 2003
Location: Indiana USA

You guys are so right!
After loaded a bleader resistor and a power capacitor, I finally measured the supposed DC voltage at the the capacitor's anode! But, still AC at the 5ar4's output. Wah.... You guys are good!
Thanks,
Lhchen
__________________
The best way to stop rust on transformers is to power them up.
  Reply With Quote
Old 14th February 2005, 06:52 AM   #17
diyAudio Member
 
audiousername's Avatar
 
Join Date: Jul 2004
Location: Melbourne, Victoria
Quote:
Originally posted by martinab2
Ok, this might be a silly question... but its not clear from you schematic. I'm assuming that the ht transformer is centre tapped with the centre connection being the negative side of your circuit. Can you confirm that this is the case?
Nice pick up, Martin I never thought it was something so basic...

Lhchen, don't give up on valve rectifiers - the transformer is the problem, and not the rectifier. I suppose you could try using two solid state diodes to make a hybrid Graetz bridge rectifier using your transformer without a centre tap. I think you should get 700VDC or so out of it that way.
__________________
Jason
  Reply With Quote
Old 14th February 2005, 08:32 AM   #18
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by audiousername
I suppose you could try using two solid state diodes to make a hybrid Graetz bridge rectifier using your transformer without a centre tap.
something like this...
Attached Images
File Type: gif graetz-hybrid-fw-bridge.gif (8.2 KB, 137 views)
  Reply With Quote
Old 14th February 2005, 08:34 AM   #19
diyAudio Member
 
audiousername's Avatar
 
Join Date: Jul 2004
Location: Melbourne, Victoria
Yep, that's exactly what I meant!
__________________
Jason
  Reply With Quote
Old 14th February 2005, 09:10 PM   #20
diyAudio Member
 
Join Date: Aug 2003
Location: Indiana USA
Quote:
Lhchen, don't give up on valve rectifiers - the transformer is the problem, and not the rectifier. I suppose you could try using two solid state diodes to make a hybrid Graetz bridge rectifier using your transformer without a centre tap. I think you should get 700VDC or so out of it that way.
I am using that Graetz already. Thanks for the help!
I have never tried this tube rectifier before. It's too much trouble really. I am considering 5ar4 this time, because I got a large Lundahl transformer and a large chassis. There is plenty of power and space to WASTE.
Thanks for all the help
Lhchen
__________________
The best way to stop rust on transformers is to power them up.
  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
bad 5ar4? sturmj Tubes / Valves 2 11th February 2009 07:09 PM
Unsolved problem EL34/12AT7/5AR4 Delphaure Tubes / Valves 1 4th October 2008 07:55 PM
Got 5AR4 For Sale? john65b Swap Meet 0 3rd April 2008 07:59 PM
6v 5AR4? pftrvlr Tubes / Valves 7 9th February 2008 01:32 AM


New To Site? Need Help?

All times are GMT. The time now is 01:09 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