The simplistic Salas low voltage shunt regulator - Page 546 - 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 9th October 2012, 02:39 PM   #5451
alibear is offline alibear  United Kingdom
diyAudio Member
 
Join Date: Feb 2009
Location: Somerset
Hi all, this is my first post to this excellent thread.
I am going to construct +ve and -Ve Version 1 regulators for the input stage,VAS and pre-driver stage of a Krell clone I am building (still )and would like some advice please.
Would it advisable to build a + and - regulator for each channel eg 4 regulators or would one pair be OK for both channels?
What would be a ball park figure for biasing the CCS?
Would a 35-0-35 transformer be suitable, I want an output between 30V and 37V (Yet to be decided )
Thanks for your help.
Alan
  Reply With Quote
Old 9th October 2012, 02:40 PM   #5452
agussug is offline agussug  Indonesia
diyAudio Member
 
Join Date: Jul 2010
Quote:
Originally Posted by Phisci View Post
More questions if I may: Can I run several loads off 1 shunt reg (for example 74hc74 flip flop as well as a DAC (+5V))?
What about using one transformer with multiple secondaries to power several of the shunt regs?
Yes you can put several loads on 1 regulator. But I think it's not good idea to power the logic IC and the DAC especially the analog part from 1 regulator.
No problem in my experience to use multiple secondary trans to power several regulators.

Regards
  Reply With Quote
Old 9th October 2012, 06:36 PM   #5453
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by alibear View Post
Hi all, this is my first post to this excellent thread.
I am going to construct +ve and -Ve Version 1 regulators for the input stage,VAS and pre-driver stage of a Krell clone I am building (still )and would like some advice please.
Would it advisable to build a + and - regulator for each channel eg 4 regulators or would one pair be OK for both channels?
What would be a ball park figure for biasing the CCS?
Would a 35-0-35 transformer be suitable, I want an output between 30V and 37V (Yet to be decided )
Thanks for your help.
Alan
Hi, Alan

One pair can go 90% the way, if the driver stages are heavily biased so they don't move individual current consumption too much.
150mA more than load consumption is a good point. You should decide config and know/measure the consumption of what it will feed.
The Tx sounds adequate for enough Vin to Vout distance.
  Reply With Quote
Old 9th October 2012, 07:23 PM   #5454
alibear is offline alibear  United Kingdom
diyAudio Member
 
Join Date: Feb 2009
Location: Somerset
Hi Salas, thanks for the reply.The drivers for the output stage will be supplied from the high current supply that also feeds the output transistors. The PCB's I have for the Krell look easy to split the tracks before the drivers, so the shunt regulator will only be feeding the input and VAS. Sorry if my wording is confusing.
Thanks
Alan
  Reply With Quote
Old 9th October 2012, 07:39 PM   #5455
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Alright, use a small resistor in series like 0.1 to 1R when you will do the split of what you have to use the regs for, with a dvm and the drop across that resistor when you drive with a 1khz sine wave just before clip see with Ohm's law what those stages draw for current. Sum what is for each reg to feed, add 150mA for CCS setting figure.
  Reply With Quote
Old 10th October 2012, 01:13 AM   #5456
diyAudio Member
 
Kazuo Ozawa's Avatar
 
Join Date: May 2006
Location: Japan
Default Reflektor +3.3V with STP55NF06L

Quote:
Originally Posted by Salas View Post
Lets hope it will open the Mosfet gate less capacitive at least.
The gate is fully open at last.
I implemented STP55NF06L into Reflektor as Salas suggested, getting great improvement.
When I used with 2SK2586, the sound was harsh. Now there is nothing, but clear ,smooth and dynamic. Especially transparency and 3-D reality is remarkable.

I have adopted four wire configuration for the first time, and surprised that the effect is very big comparing to two wire.

Zobel value is not optimized for sound quality whereas there is no oscillation at all.

Thanks Salas and other Reflektor lovers.
Attached Images
File Type: png Salas Reflektor (+3.3V) 7th.png (35.5 KB, 531 views)
File Type: jpg Top.jpg (139.6 KB, 525 views)
File Type: jpg Bottom.jpg (176.5 KB, 513 views)
  Reply With Quote
Old 10th October 2012, 06:53 AM   #5457
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Great. Zobel is 'not' optimized, or is 'now' optimized?

P.S. Is there a Z Foil resistor in the picture between trimmer and a BJTs pair?
  Reply With Quote
Old 10th October 2012, 07:39 AM   #5458
Phisci is offline Phisci  South Africa
diyAudio Member
 
Join Date: Aug 2012
Salas, in the REFLEKTOR, just to confirm:
1. that the CCS current is (2N4403)Vbe/R1?
2. And this should be = load current plus shunt current
3. The dissipation on 9610 mosfet is (Vin-Vout)*(CCS current)
4. The dissipation on 640 mosfet is (Vout)*(CCS current-Load current)

Thus when adjusting the Reflektor for different optinal currents, the best way would be to change R1?

Your help much appreciated.
  Reply With Quote
Old 10th October 2012, 07:42 AM   #5459
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Confirming all points above.
  Reply With Quote
Old 10th October 2012, 07:55 AM   #5460
Phisci is offline Phisci  South Africa
diyAudio Member
 
Join Date: Aug 2012
Excellent, thanks,
Forgot 1 more: Total CCS should be equal to at least 150mA + load current?
And 1 more: why does Kazuo get better results with a STP55NF06L? What chnages in going from 640? What alternatives would you suggest to STP55NF06L if not available?
  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



New To Site? Need Help?

All times are GMT. The time now is 03:03 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