Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Return to Tube DIY Asylum

Mark Kelly's Heater Regulator - modified

80.213.163.150
Posted on October 30, 2009 at 00:57:19
johs
Audiophile

Posts: 31
Joined: April 22, 2003



I have tweaked Mark Kelly's circruit a few times now and been in a bad mood from all kinds of unstable performance. The end result looks like the image included. Have been running some time and seems to be working ok. Any comment, please!
PS! I changed my "name" earlier - should not be johs50.
RE: Mark Kelly's Heater Regulator - modified, posted on October 30, 2009 at 07:37:40
SomeJoe
 what is the current set and what tube is this circuit being used for?
RE: Mark Kelly's Heater Regulator - modified, posted on October 30, 2009 at 10:03:32
johs
Audiophile

Posts: 31
Joined: April 22, 2003
 It is 6,3V at 600mA, i.e. R1 is 0R9 and app. 100mA is shunted throu Q5. It is no problem adjusting this circruit to 5V. If you build one supply pr. tube the TL431 circruit may be ommitted, but if more than one tube is used and you get a broken heater voltage will rise.
johs.

RE: Mark Kelly's Heater Regulator - modified, posted on October 30, 2009 at 13:06:38
Triode_Kingdom
Audiophile

Posts: 629
Location: Travelin' Man
Joined: September 24, 2006
 "if more than one tube is used and you get a broken heater voltage will rise."

That's the problem with current regulators. What's really needed is a current *limiter* (clamp), or maybe just a simpler design like a LM317 that can be installed at each filament.
RE: Mark Kelly's Heater Regulator - modified, posted on October 30, 2009 at 16:42:36
johs
Audiophile

Posts: 31
Joined: April 22, 2003
 The TL431 will keep the output voltage constant whatever happens to the heaters.

RE: Mark Kelly's Heater Regulator - modified, posted on October 30, 2009 at 01:00:54
johs
Audiophile

Posts: 31
Joined: April 22, 2003
 Sorry I forgot to include a link to Mark Kelly's article.

Removed, posted on October 31, 2009 at 17:29:44
Mark Kelly
Manufacturer

Posts: 6519
Location: Geelong, VIC
Joined: February 28, 2002
Contributor
  Since: November 3, 2004
 I'd been meaning to remove that material for a while. Thanks for reminding me.

Mark Kelly
RE: Removed, posted on November 1, 2009 at 00:54:48
johs
Audiophile

Posts: 31
Joined: April 22, 2003
 Hello Mark,
Does that mean that this circruit does not do the job of insolating the heaters from the mains supply good enough. The TL431 does keep voltage constant - will it harm the function in other ways?

Page processed in 0.031 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2009, Audio Asylum, all rights reserved ] [ Go Green ] [ Take5 ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]