5 VDC heater 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 20th June 2007, 04:33 PM   #1
sgerus is offline sgerus  United States
diyAudio Member
 
Join Date: Nov 2005
Location: Milwaukee, WI
Default 5 VDC heater question

Here is a simple C-RC-RC 5vdc power supply for a 300b filament.
(see attachment)

I would like to use the 6.3vac 6A from T1, which would be about 7vac at 1.3A.

According to the Power Supply Designer II s/w there will be 3mv p-p ripple.

Is 3mv of ripple low enough?
Do you recommend a filament choke?

Thanks
Attached Images
File Type: jpg snag-0018.jpg (78.7 KB, 266 views)
  Reply With Quote
Old 20th June 2007, 09:23 PM   #2
Colt45 is offline Colt45  Serbia
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Send a message via ICQ to Colt45
3mV of ripple is better than 5V
  Reply With Quote
Old 21st June 2007, 07:30 AM   #3
diyAudio Member
 
Join Date: May 2007
Quote:
Is 3mv of ripple low enough?
Do you recommend a filament choke?
If 3mV is low enough depends on the sensitivity of your loudspeakers.

You can find my story here: Heater supply

John Atwood also performed some research on this topic:
DC filament supply test
  Reply With Quote
Old 21st June 2007, 03:41 PM   #4
sgerus is offline sgerus  United States
diyAudio Member
 
Join Date: Nov 2005
Location: Milwaukee, WI
Gerrit, Thanks for that info.

So the choke is the way to go if you have the room for it and a few more $.

According to PUS Designer II s/w, a RC-RC has about the same ripple voltage as a LC filter.

For my PUS Designer II comparison I used:
C-RC-RC 10,000uf - 1R - 10,000uf - 1R - 10,000uf
Vrs
C-LC 10,000uf - 60mH 10,000uf

It would be interesting to see how the RC-RC filter looks on the Audio Precsion System 2 that John Atwood used on his test.
  Reply With Quote
Old 21st June 2007, 05:48 PM   #5
diyAudio Member
 
zigzagflux's Avatar
 
Join Date: Oct 2006
Location: Charlotte, NC
Quote:
Originally posted by sgerus
It would be interesting to see how the RC-RC filter looks on the Audio Precsion System 2 that John Atwood used on his test.
I suspect not as good, especially in the higher order harmonics. While you may be able to produce the same 120Hz ripple with the RC-RC, the choke input is much friendlier with high order harmonic content, drawing a more sinusoidal current from the transformer.

I suggest comparing in PSUD not only the output, but take a look at the input waveforms. True rms values will be different, due to the harmonics. Also compare ripple current requirements for the capacitors; they will be very different. Lower ripple current results in longer life for an electrolytic capacitor.

Fewer high order harmonics makes for less noise. Aside of cost and weight, there are only good things to be had with choke filters.
  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
Simple heater question athos56 Tubes / Valves 4 27th May 2009 06:31 PM
5687 filament heater question dr._sleep Tubes / Valves 2 25th August 2005 04:45 AM
Heater Question lpd Tubes / Valves 4 20th February 2005 06:35 PM
DHT DC heater question etalon90 Tubes / Valves 5 1st January 2005 10:34 PM
Heater winding load question. G Tubes / Valves 3 22nd May 2004 07:40 PM


New To Site? Need Help?

All times are GMT. The time now is 08:31 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