Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Cap size for Hg Rectifiers
Cap size for Hg Rectifiers
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 February 2007, 08:00 PM   #1
Steven-H is offline Steven-H  United States
diyAudio Member
 
Join Date: Jan 2007
Location: The 1st State
Default Cap size for Hg Rectifiers

All,
I have tried to look at some data sheets in the last couple of days, but I haven't been able to find this answer....
What is the acceptable input cap value for Mercury Vapor rectifiers (Namely interested in the 83/816) to make it live a happy life ?

Thanks !
Steve
  Reply With Quote
Old 6th February 2007, 08:43 AM   #2
bembel is offline bembel  Europe
diyAudio Member
 
bembel's Avatar
 
Join Date: Aug 2006
Send a message via Yahoo to bembel
hi,
IIRC it's less than 40µF with an input choke > 3H (for a 83)

hope this helps.
__________________
Plus je pédale moins vite, moins j'avance plus vite !
  Reply With Quote
Old 6th February 2007, 09:30 AM   #3
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Zero. Hg rectifiers are intended for choke input because of their negative output resistance.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 6th February 2007, 09:44 AM   #4
bembel is offline bembel  Europe
diyAudio Member
 
bembel's Avatar
 
Join Date: Aug 2006
Send a message via Yahoo to bembel
Oops I was meaning 40µF after the >3H input choke.
sorry & thanks EC8010
__________________
Plus je pédale moins vite, moins j'avance plus vite !
  Reply With Quote
Old 6th February 2007, 09:51 AM   #5
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
No apology necessary - I can't make myself as clearly understood in French as you can in English.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 6th February 2007, 10:03 AM   #6
bembel is offline bembel  Europe
diyAudio Member
 
bembel's Avatar
 
Join Date: Aug 2006
Send a message via Yahoo to bembel
those are explosive mistakes !
__________________
Plus je pédale moins vite, moins j'avance plus vite !
  Reply With Quote
Old 6th February 2007, 12:03 PM   #7
Steven-H is offline Steven-H  United States
diyAudio Member
 
Join Date: Jan 2007
Location: The 1st State
Thanks Gents....This leads me to another question.

In looking here:
http://www.diytube.com/st35/ST35_5AR4PS.pdf

One can see the PSU arrangement. I will be subbing in an 83 tube, so by taking your recommendations I will be ditching C9, and increasing the choke to 5H or so. Any other changes ? I already have a timer delay circuit in place, so the preheating issues are taken care of.

Secondly, the main cause for me asking this question is I wish to use a set of 816s in my PSU that will power my preamp/phonostage. I've been playing around with PSUd for a while, but I haven't been able to come up with anything too impressive. I guess I have a couple of issues; first one being that I am using an 83 tube to design the circuit; as PSUd doesn't have the 816 (But I believe it would be pretty close...). Secondly, I was planning on using a set of 0D3 regulator tubes; of which PSUd doesn't have as well. Do any of you have some tried and true suggestions ?

Thanks again,
Steve
  Reply With Quote
Old 6th February 2007, 12:47 PM   #8
sorenj07 is offline sorenj07  Germany
diyAudio Member
 
sorenj07's Avatar
 
Join Date: May 2006
Location: Berlin
Taking out the input cap from the power supply will drop your voltage by a LOT. instead of multiplying the transformer's AC voltage by root 2, you decrease it by 10%. Unless you have a much higher voltage power transformer than the one DIYTube specifies, you won't be able to use this schematic.
  Reply With Quote
Old 6th February 2007, 04:35 PM   #9
Steven-H is offline Steven-H  United States
diyAudio Member
 
Join Date: Jan 2007
Location: The 1st State
Thanks.......So I suppose my option is now to either use a 450v or so transformer; or a 'normal' rectifier tube....
  Reply With Quote
Old 6th February 2007, 04:39 PM   #10
rdf is offline rdf  Canada
diyAudio Member
 
rdf's Avatar
 
Join Date: Jun 2004
Location: big smoke
Most spec sheets for the 83 mention operation with a capacitor input, typically with a min recommendation of 50 ohms total source impedance in series with each plate when using a 4 uF input cap. Why the big fat 'zero'?
  Reply With Quote

Reply


Cap size for Hg RectifiersHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
UCD 400 - Rectifiers kephaudio Class D 1 21st May 2005 07:06 PM
Speaker size v Room size cliffy Multi-Way 6 19th February 2005 08:34 AM
How many rectifiers? Valverine Tubes / Valves 6 15th February 2004 03:00 AM


New To Site? Need Help?

All times are GMT. The time now is 08:04 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki