regulator for TSE driver tube - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Tubelab

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 1st December 2011, 05:02 PM   #1
jrenkin is offline jrenkin  United States
diyAudio Member
 
Join Date: Nov 2007
Location: Denver, Colorado
Default regulator for TSE driver tube

Is there any reason I can't just insert a voltage regulator like this 7806 +6V Voltage Regulator TO-220 7806 to the 5842 heaters? As long as I have the starting voltage?
  Reply With Quote
Old 2nd December 2011, 02:31 AM   #2
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
The 7806 regulator needs at least 8 volts on its input in order to work. In practice it needs a bit more since the lowest point in the ripple voltage must be 8 volts. I doubt that the heater supply gets up to 8 volts in a TSE. The Sharp regulator that I used was chosen for its low dropout voltage. It only needs 5.5 volts input to make 5 volts, or 3.2 volts input to make 2.5 volts.

The DHT's used in the output stage are rather sensitive to the filament voltage, and I want pure DC to eliminate the 60 Hz and 120 Hz IMD products that are created by running a DHT on AC. The 5842's are not overly critical of their heater voltage and AC is OK, so unregulated DC is better. Since every power transformer is different and our line voltages are a wild card it might be a good idea to measure the actual heater voltage once the amp is built and adjust the value of R3 to get 6.0 to 6.6 volts across the tubes.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 3rd December 2011, 02:44 AM   #3
diyAudio Member
 
Join Date: May 2009
Red face R3 Value too low?

Or am I missing something?
6.3V x 1.41 = 8.9V; 300ma per filament X 2 = 600ma x 2.2 ohm (schematic value) = 1.3V; net to filaments = 7.6V? Should R3 = 4.2 ohm?
  Reply With Quote
Old 3rd December 2011, 01:29 PM   #4
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
Or am I missing something?......6.3V x 1.41 = 8.9V
You never get 1.41 X the secondary voltage since the caps can't stay charged if the diodes only conduct at the peak of a cycle. The average is about 1.2 to 1.3 X the secondary voltage.

Each diode has a voltage drop. The silicon diodes are about .7 to .8 volts and the Schottkey is about .3 to .4 volts. There are one of each in the 5842 heater circuit for a 1 to 1.2 volt drop.

There are three wild cards here that can't be figured out with math.

Many transformers deliver more voltage than their ratings, especially Hammonds. It is not uncommon for a Hammond to deliver 7 volts or more on the 6.3 volt winding even when drawing more than the rated load current.

Todays line voltage can be anywhere from 115 to 127 volts.

The distortion present on the line voltage can be 10% or more. The distortion is usually flat topping on the sine wave which will further reduce the 1.2 to 1.3 X factor that I quoted above.

Most TSE's are within 6.0 to 6.6 volts with a 2.2 ohm resistor, but some builders have seen excessive voltage and switched to a 2.4 or 2.7 ohm ressitor.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 3rd December 2011, 02:56 PM   #5
jrenkin is offline jrenkin  United States
diyAudio Member
 
Join Date: Nov 2007
Location: Denver, Colorado
Thanks!
  Reply With Quote
Old 3rd December 2011, 04:57 PM   #6
diyAudio Member
 
Join Date: May 2009
Default Appreciate the explanation

My thanks also - so much to learn when you start out as an ME instead of an EE.
  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
45 TSE desired tube current? Acceptable B+? Alan Hope Tubelab 8 5th December 2011 12:07 PM
Bad TSE Input Tube? jeffx Tubelab 10 29th October 2011 02:55 AM
TSE Parts TerribleT Tubelab 12 14th October 2011 04:55 PM
Tube regulator MrCurwen Tubes / Valves 8 24th March 2011 10:04 AM
Tube Regulator Jay Tubes / Valves 51 5th April 2003 04:07 PM


New To Site? Need Help?

All times are GMT. The time now is 10:10 AM.


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