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

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Futterman Class C oscillator?
Futterman Class C oscillator?
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 27th February 2017, 04:16 AM   #51
Koonw is online now Koonw
diyAudio Member
 
Join Date: Apr 2013
"I found some cheap selections for capacitors online, and was wondering if this would be good enough to smooth out the ripples enough.

Whatever electrolytic cap you used make sure they're tested before put them in use. You need to match the cap by their leakage current very closely so the voltage are equal across each cap. This is done by measure the voltage in resistor series with cap connected to power supply. As you remove the supply, the capacitance should be retained for days, the one gone down too fast is not good.

Another question is the idea of using another M.O.T as a massive choke. Ive heard people suggesting this idea, but never heard conclusions on why not to do this. It is a big clump of iron thats mass produced. Seems cheap enough"

Choke needs lot of lamination to produce high inductance at low freq, lump of iron makes a low efficiency choke, and heat since it is not as efficient, IMO. Better to take apart a PSU transformer and rearrange the EI lamination.

Last edited by Koonw; 27th February 2017 at 04:27 AM.
  Reply With Quote
Old 27th February 2017, 04:26 AM   #52
Koonw is online now Koonw
diyAudio Member
 
Join Date: Apr 2013
Also, as im drawing this up, I continue enjoying the thought that this can multi purpose as a music amp as well. The only thing that would change is the RC bias values at the grids of each 811a right? But because of the way this totem-pole design draws current, I shouldn't have to push the bias into class C like behavior (conducting at a fraction of the cycle) to reach reasonable efficiencies while preserving the ability to drive speakers for audio?

oh and perhaps the fact that the impedance output with the 811a tubes might be too high to direct drive right? :c

The audio feature would be novel, but if it begins to over complicate things, I can do without it. I like the idea of flicking a bias switch to get a different behavior out of this design.


The optimal load would be about 1K. So you can't connect 8 ohms speaker directly without a step down transformer. Extra bias needs not be used as zero bias is fine for 811a (not for 6c33c though). There is a 200W audio amp in RCA 811a datasheet, which shows how it's done.
  Reply With Quote
Old 28th February 2017, 07:48 AM   #53
woodrough is offline woodrough  United States
diyAudio Member
 
Join Date: Aug 2012
is 5H on each side too skimpy for my application?
What about at 150ma.
Looking for areas to cut cost when I can Found a good array of choices for 5 to 10H sizes.

I may just get a bunch of new capacitors from mouser, there are some cost effective choices there at those voltages.

I may end up making a separate 6c33c amp after this totem pole 811a design
  Reply With Quote
Old 1st March 2017, 03:02 AM   #54
woodrough is offline woodrough  United States
diyAudio Member
 
Join Date: Aug 2012
I got a couple of 10k 10w resistors in the mail today so I tried it out and got some improved results. Improved results as in being able to go up to the 60v - 80v line on my variac before I started getting some light arcing in my tuning capacitor. Moved to my home made cup capacitors and saw improvement in stability when not arcing over.
The grid resistors get pretty darn hot after some good 5 min running Though
  Reply With Quote
Old 2nd March 2017, 06:04 AM   #55
Koonw is online now Koonw
diyAudio Member
 
Join Date: Apr 2013
Quote:
Originally Posted by woodrough View Post
is 5H on each side too skimpy for my application?
What about at 150ma.
Looking for areas to cut cost when I can Found a good array of choices for 5 to 10H sizes.

I may just get a bunch of new capacitors from mouser, there are some cost effective choices there at those voltages.

I may end up making a separate 6c33c amp after this totem pole 811a design
If you want to simulate the PSU, try to download PSU2, that will help to see if the components meet the criteria.
  Reply With Quote
Old 5th March 2017, 07:39 AM   #56
woodrough is offline woodrough  United States
diyAudio Member
 
Join Date: Aug 2012
Thats a good resource. I had to get out my old windows partition out to see the software but its working well now.
I realized that my last drawing has capacitor placement designed to create inrush current.

Im still playing with it and other downloadable samples to get familiar with it
  Reply With Quote
Old 22nd December 2017, 06:50 AM   #57
MadsKaizer is offline MadsKaizer  Denmark
diyAudio Member
 
Join Date: Nov 2008
Location: Denmark
I can see that it is one of my old schematics that was posted in the original first post, so I just wanted to point towards the new url where all information can be found

Kaizer VTTC I | Kaizer Power Electronics
  Reply With Quote

Reply


Futterman Class C oscillator?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Futterman H-3 desperateaudio Tubes / Valves 41 29th December 2016 06:37 PM
Futterman H3 Set Up desperateaudio Tubes / Valves 3 6th February 2015 07:19 PM
Use of a Ribidum Oscillator as refrence oscillator in a DAC Mark A. Gulbrandsen Digital Line Level 19 2nd November 2014 02:35 AM
Improving the Futterman Sch3mat1c Tubes / Valves 6 18th August 2003 10:35 PM


New To Site? Need Help?

All times are GMT. The time now is 11:43 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki