Simplistic Mosfet HV Shunt Regs - Page 166 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 2nd March 2011, 08:22 PM   #1651
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Hi Salas,

On my DAC output stage.

Click the image to open in full size.

If I do Vin-Vout >= 15V there is hardly any extra shunt current at all. BUT I can already hear an improvement.
Only after Vin-Vout >= 90V there is about 55mA total current drawn. Resistor is 29R and voltage across it 1.63 or so.

I use dvb-projekt's boards.
Click the image to open in full size.
Attached Images
File Type: gif 6n6p_rakk.gif (53.1 KB, 1119 views)
File Type: jpg ssssr.jpg (85.6 KB, 1131 views)

Last edited by Bas Horneman; 2nd March 2011 at 08:24 PM.
  Reply With Quote
Old 2nd March 2011, 08:28 PM   #1652
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
So this is 14mA per channel load (5.6V on 390Rk). See to have 55-60mA indicated by the Vdrop on R1 ''Current Adj.'' divided by its value. If you are using double mono regs see to have 40mA on each R1.
  Reply With Quote
Old 2nd March 2011, 08:30 PM   #1653
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Each half of the 6n6p drew around 14,5mA before the SSSSR was installed. (Edit: Oops posted this before I saw your answer)

I just dawned on me that if the voltage goes down because of the regulator. The tube will draw less as well.....
  Reply With Quote
Old 2nd March 2011, 08:33 PM   #1654
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
f you are using double mono regs see to have 40mA on each R1.
I'm using one at the moment. So I was aiming for (14,5+14,5)*2+25mA=85mA.
  Reply With Quote
Old 2nd March 2011, 08:36 PM   #1655
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
If you use 56R current Adj. it will set circa 40mA with average LEDS and Vgs. That is not enough if you supply two channels. The reg needs +25mA on top of that 30mA to the channels, for its own consumption purposes. 85mA is nice, drops its impedance a bit more, but your sinks look like are going to be taxed a bit. What is the value of your current Adj. resistor and what is the vdrop across it?
  Reply With Quote
Old 2nd March 2011, 08:37 PM   #1656
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
current Adj. resistor and what is the vdrop across it? Common reg for both channels?
29R.(Two 56R in parallel) Voltage drop 1,63. And common reg for both channels yes. (But then the IRF840 and MJE350 become 90 degrees celcius) and there is major voltage drop.

Last edited by Bas Horneman; 2nd March 2011 at 08:42 PM.
  Reply With Quote
Old 2nd March 2011, 08:49 PM   #1657
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
That means 56mA CCS. Which is +26mA above your load demand. That is correct use. It also means around 6W dissipation for the IRF840 on that little sink. Maybe you have a mini sink to bolt on the MJE350? That would help it. Where and how much there is major voltage drop?
  Reply With Quote
Old 2nd March 2011, 08:54 PM   #1658
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
Where and how much there is major voltage drop?
What I was trying to say is that I only get that much current to be shunted if I dial the pot way down to 135V or so. (voltage drop)

And I did not solder the heat sinks in because I thought they would be too small. But that is all I had that fitted. I guess I'll have to go dual mono. And I might increase the b+ by going solid state rectifier and removing the CLCLCR with just some CR.
  Reply With Quote
Old 2nd March 2011, 09:03 PM   #1659
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Just did some quick measurements:

200v=36mA
180v=43,5mA
160v=50mA
  Reply With Quote
Old 2nd March 2011, 09:08 PM   #1660
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
That board was made by DVB for a certain DAC output stage, I think for under 200V B+ and less consumption. Its better you will use double mono so to have less heat when you go above 200V and the sinks to suffice. I recommend using a dummy load calculated for target load consumption at projected B+. Like 15K//15K (10W each) across 233V for 30mA, or just one for 15mA and be setting R1 for the proper +25mA margin by experiment. Then connecting to the real preamp.
  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
Regs - Shunt vs Series richie00boy Solid State 42 14th March 2013 06:45 PM


New To Site? Need Help?

All times are GMT. The time now is 04:35 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