power supply problem - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 28th June 2010, 01:18 AM   #1
diyAudio Member
 
Join Date: Feb 2010
Location: calgary alberta tundra canada
Default power supply problem

can anyone tell me why im not getting 250 votls from the voltage doubling circuit in the bottom right of the diagram? im measuring 60 volts across each capacitor when they should read 120 each i think.

this is a circuit based on an 13em7 tube

thanks
Attached Images
File Type: gif miniblok.gif (8.1 KB, 287 views)

Last edited by chopchip; 28th June 2010 at 01:25 AM.
  Reply With Quote
Old 28th June 2010, 01:37 AM   #2
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Measure the voltages on the transformers that might give a clue.
  Reply With Quote
Old 28th June 2010, 01:51 AM   #3
diyAudio Member
 
Join Date: Feb 2010
Location: calgary alberta tundra canada
Quote:
Originally Posted by nigelwright7557 View Post
Measure the voltages on the transformers that might give a clue.

i get 120 volts after T2
  Reply With Quote
Old 28th June 2010, 01:52 AM   #4
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
You must have D2 connected to the bottom of the transformer instead of the top.
  Reply With Quote
Old 28th June 2010, 01:57 AM   #5
diyAudio Member
 
Join Date: Feb 2010
Location: calgary alberta tundra canada
Quote:
Originally Posted by gootee View Post
You must have D2 connected to the bottom of the transformer instead of the top.

there is a bottom and top? but it is ac, i thought it wouldnt make any difference. do you mean the secondary or primary windings?
  Reply With Quote
Old 28th June 2010, 02:03 AM   #6
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Quote:
Originally Posted by chopchip View Post
there is a bottom and top? but it is ac, i thought it wouldnt make any difference. do you mean the secondary or primary windings?
On the schematic, D2 should connect to the transformer where D1 does, not on the other end of that winding. Otherwise, the voltage will not be doubled.

Last edited by gootee; 28th June 2010 at 02:05 AM.
  Reply With Quote
Old 28th June 2010, 02:10 AM   #7
diyAudio Member
 
Join Date: Feb 2010
Location: calgary alberta tundra canada
Quote:
Originally Posted by gootee View Post
On the schematic, D2 should connect to the transformer where D1 does, not on the other end of that winding. Otherwise, the voltage will not be doubled.

i have it wired exactly like the diagram. maybe i need to sleep on it and take fresh look to-morrow
  Reply With Quote
Old 28th June 2010, 02:29 AM   #8
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Are you measuring for DC across C3?

If it's wired correctly and you get about 160 to 180 V DC (or average) across C3 instead of about 330 V DC, then one of D1, D2, C1, or C2 might be shorted.

Actually, if D1 or D2 were shorted, you'd get about 174 volts average (177 V RMS) across C3, but with about 95 volts of 60 Hz AC riding on it.

If C1 or C2 were shorted, you'd get about 165 V DC across C3, with probably about 306 mV of 60 Hz ripple riding on it.

And if everything is OK, you should get a nominal 329 V DC across C3, with about 320 mV of 60 Hz ripple. (Values may be different, depending on load. I assumed you would be pulling about 70 mA from it.)

Cheers,

Tom

Last edited by gootee; 28th June 2010 at 02:48 AM.
  Reply With Quote
Old 28th June 2010, 02:41 AM   #9
diyAudio Member
 
Join Date: Feb 2010
Location: calgary alberta tundra canada
im looking at a java voltage doubler demonstration and i dont see a ground connection there. is this a problem?
  Reply With Quote
Old 28th June 2010, 02:52 AM   #10
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Do you have the ground connected as shown in your schematic?

P.S. You might want to do a CTRL-Refresh, in case you didn't get all of the edits I did on my last message.
  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
Power supply problem vidc Power Supplies 9 26th May 2010 05:29 PM
Help on power supply problem t2060079 Solid State 13 28th July 2008 02:23 AM
Power supply problem krzanik Tubes / Valves 19 1st May 2007 03:56 PM
Power supply problem argonrepublic Parts 0 23rd January 2006 05:35 AM
Power supply problem PassFan Tubes / Valves 6 24th October 2003 10:03 PM


New To Site? Need Help?

All times are GMT. The time now is 02:57 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