Volts D.C. panel meter for B+ - 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 19th December 2009, 04:19 PM   #1
btran is offline btran  United States
diyAudio Member
 
btran's Avatar
 
Join Date: Jul 2009
Location: Sugar land, Texas
Default Volts D.C. panel meter for B+

I have builted the tubelab SE and I just wonder how to put in the Volts D.C. panel meter to monitor the B+ voltage. Advices are greatly appreciated!

Regards,

Binh
  Reply With Quote
Old 19th December 2009, 05:07 PM   #2
Glowbug is offline Glowbug  United States
diyAudio Member
 
Glowbug's Avatar
 
Join Date: Feb 2006
Location: Hillsborough, NC/McLean, VA
Wire it in parallel...just like you'd test it with a DMM

Good meters are available from places like Surplus Sales of Nebraska or Mouser...
__________________
Jim J.
  Reply With Quote
Old 19th December 2009, 08:51 PM   #3
btran is offline btran  United States
diyAudio Member
 
btran's Avatar
 
Join Date: Jul 2009
Location: Sugar land, Texas
I did a test which hook it up the Simpson (ohms per volt 600 DCV) with a power supply 9 DCV at 0-25 mA and the needle went all the way. I think it needs a circuitry to do a job.
  Reply With Quote
Old 19th December 2009, 09:02 PM   #4
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Probably the meter is just an ammeter and it expects a series resistor.
Look for a marking that gives the FSD (Full Scale Deflection) current. You can use this with the meter resistance to calculate the value of resistor required.
This link: RADIO AMATEUR EXAM
explains far better than I can.
  Reply With Quote
Old 19th December 2009, 10:42 PM   #5
diyAudio Member
 
Steerpike's Avatar
 
Join Date: Jan 2006
Location: Johannesburg, South Africa
Something I'd do: put a Zener diode of around 100V to 200V inseries with the meter and its resistor. That way you shift the meter zero by 100V or 200V or whatever you want. Then your meter scale runs from 100V up to 250V ( or 200V-350V) or whatever you want, instead of 0v up to 250V. This give a more acurate expanded scale, since measuring below 100V is not really useful.
__________________
Steerpike's Toybox
  Reply With Quote
Old 20th December 2009, 08:58 PM   #6
btran is offline btran  United States
diyAudio Member
 
btran's Avatar
 
Join Date: Jul 2009
Location: Sugar land, Texas
The volt panel meter Simpson I have is not directed hook up and it needs the 6 meg-ohms resistor in series to be function right. I just wonder would it change the B+ if I have it in parallel with R30 and what are the effects? Schematic
  Reply With Quote
Old 20th December 2009, 09:22 PM   #7
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
6Meg is very high, you must have a sensitive meter. What is the FSD current rating?

In any event, connecting the whole network (meter + series resistor) in parallel with R30 is correct. It will not affect the voltage in any measurable way.
  Reply With Quote
Old 20th December 2009, 09:32 PM   #8
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Quote:
Originally Posted by btran View Post
The volt panel meter Simpson I have is not directed hook up and it needs the 6 meg-ohms resistor in series to be function right. I just wonder would it change the B+ if I have it in parallel with R30 and what are the effects? Schematic
If this is the same meter you connected across the supply previously without the required series resistor it is highly likely that the meter has been damaged by the experience. I would test the meter with an appropriate series resistor before making any plans to install it permanently. (Most likely it is a sensitive micro-ammeter and it has been exposed to a current many orders of magnitude greater than it was designed for.) Hopefully you have another meter you can install.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 20th December 2009, 09:46 PM   #9
btran is offline btran  United States
diyAudio Member
 
btran's Avatar
 
Join Date: Jul 2009
Location: Sugar land, Texas
I try to find the data for my meter but couldn't find it. On the meter I found these info.


1000 ohms per volt
Simpson Electric Co. Elgin , Ill 60120 U.S.A.

Model 324 NO.

The Volt scale is : 0 200 400 600
0 100 200 300

I want to use it with 600 volt scale and by my calculation that I have to use 600,000 ohms or 600K, but it couldn't handle when I tried to measure 9V battery.
I just used the 2.2meg then it seem work and finally I use 6meg and tried with the power supply at 600 volts to test it. If you see some thing wrong please correct me.
  Reply With Quote
Old 20th December 2009, 10:06 PM   #10
btran is offline btran  United States
diyAudio Member
 
btran's Avatar
 
Join Date: Jul 2009
Location: Sugar land, Texas
Here is the picture of my meter
Attached Images
File Type: jpg DSC00139.JPG (392.0 KB, 136 views)
  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
Help! How to measure 2450 volts with 1000 volt max meter. ichiban Parts 8 6th June 2009 03:10 AM
power transformers 220 volts to 110 volts garydmd Chip Amps 3 7th April 2007 02:52 PM
how to make this esr meter work with 250uA Panel meter dytln_02 Everything Else 2 27th January 2007 10:13 PM
Gainclone is on 120 volts will it be fine at 220 volts? Jimmy154 Chip Amps 7 29th June 2005 12:10 AM
panel meter KCC Solid State 3 16th March 2004 05:03 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