Voltmeter to monitor an Electrostatic speaker 10000 Volt power supply - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

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 1st March 2004, 12:10 PM   #1
diyAudio Member
 
Join Date: Mar 2004
Location: Pensnett House, Pensnett Trading Estate, Kingswinford, Dudley, West Midlands. DY6 7PP England
Default Voltmeter to monitor an Electrostatic speaker 10000 Volt power supply

Dear All,

Please can you help me find or specify a voltmeter suitable for monitoring a 10000V power supply for an Electrostatic speaker?

The voltmeter must have an extremely high resistance probably much greater than 10,000,000,000 ohms to avoid over loading the power supply. The power supply has very HIGH internal resiatance.

Electrostatic voltmeters I have seen are either low accuracy (field meters?) or expensive that is greater 1500?

Yours sincerely

George Kermeen
Electronic Engineer
Dudley Designs and Technical Services Ltd
email dudleydesigns@aol.com
  Reply With Quote
Old 1st March 2004, 01:29 PM   #2
Banned
 
Join Date: Apr 2002
Location: Germany, Clausthal
does it need to be fast? else, why not a voltage divider 10000:1 with desired resistance, and a ADC over the resitor with about 1V across it? As the ADCs input would be a capacitor that is charged, the slower the ADC is, the larger the resistors could be.
  Reply With Quote
Old 1st March 2004, 01:33 PM   #3
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
What you want to do is build a high voltage probe. That's most easily done by stringing a bunch of high value resistors in series, and setting up the voltage divider that till suggested. Using a bunch of resistors in series helps get past max voltage ratings. Make sure your substrate has VERY good insulation properties- plain epoxy may not do.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 1st March 2004, 01:39 PM   #4
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Default Not what you asked, but.....

If you know the capacitance of the ES panel, you could add a series cap of suitable value, and measure with a low voltage electrostatic meter across that.
Alternatively, by knowing the source impedance of the power supply, you could use the method mentioned here:
http://www.quadesl.org/FAQs/body_faqs.html
  Reply With Quote
Old 1st March 2004, 01:58 PM   #5
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
safety first:

i don't think that a HV probe is something that easily built from scratch -- firstly with common plastics the conductivity can be much higher than those seen published due to the fillers etc. used to enhance strength. you want a plastic which is not hydrophilic in any case, you want to make sure that the there is no way your hand or fingers can slip and come into close proximity to the HV circuit.

secondly, common resistors are non-linear above a few hundred volts -- there are special high voltage resistors for this purpose

my 2 cents -- you can buy a good B&K, Heath, Fluke or Eico HV probe on the bay -- anywhere from $20 to $60. it doesn't take more than a few hundred uA to stop your heart.
  Reply With Quote
Old 1st March 2004, 02:00 PM   #6
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
All good points, Jack. Thanks.

The plastic I had in mind was Teflon or UHMW.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 1st March 2004, 02:09 PM   #7
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Reminder:
He's asking for 10G ohm.
The available probes I've seen are 100M to 1G.
  Reply With Quote
Old 1st March 2004, 02:09 PM   #8
diyAudio Member
 
ashok's Avatar
 
Join Date: Jun 2002
Location: 3RS
Default Shocking the heart

Quote:
doesn't take more than a few hundred uA to stop your heart
Yeah, and it gives you about 3 more minutes ( depending on temp ) till your brain shuts down and it gives you time to scream (silently) and curse yourself for not having been more careful. It must be awful -- shutting down almost consciously --.......... it happened to someone I knew very well ! Awful for everyone else too.
So BE CAREFUL ! People care more about you than you imagine !

Be safe and have fun.
Cheers.
__________________
AM
  Reply With Quote
Old 1st March 2004, 02:13 PM   #9
Tobbe_L is offline Tobbe_L  Sweden
diyAudio Member
 
Join Date: Dec 2003
Location: Gbg
You can easily find high-voltage probes that can measure up to 40 kV, so that is not a problem.
But finding something with an input impedance of more than 10 GOhm will be a problem, to be honest I am not even sure such a thing exist. You also need a decent multimeter (with an input impedance >10 MOhm) in order to use such a probe.

Are you sure 1 GOhm would not be enough? Then for example a Fluke 80k-15 would probably work.

I should also point out that I think it would be VERY difficult to make a DIY probe with a imput impedance anywhere near what you can find in commercial probes.
  Reply With Quote
Old 1st March 2004, 03:07 PM   #10
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally posted by Tobbe_L
You can easily find high-voltage probes that can measure up to 40 kV, so that is not a problem.
But finding something with an input impedance of more than 10 GOhm will be a problem, to be honest I am not even sure such a thing exist. You also need a decent multimeter (with an input impedance >10 MOhm) in order to use such a probe.

Are you sure 1 GOhm would not be enough? Then for example a Fluke 80k-15 would probably work.

I should also point out that I think it would be VERY difficult to make a DIY probe with a imput impedance anywhere near what you can find in commercial probes.
maybe with the TEK R7704 I am desparately trying to give away I should include a HV probe.
  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
12 volt power supply for tube amps caraudionut Tubes / Valves 9 27th April 2007 03:04 PM
how to build a 12 volt dc power supply? michelevit Class D 5 22nd December 2006 07:53 AM
How to use a 220 Volt power supply at 12 Volts in the car? Mr. Old School Car Audio 3 10th March 2006 12:11 AM
Can you adapt a computer power supply for the 5v and 6.3 volt needs? Original Burnedfingers Tubes / Valves 10 27th November 2002 11:22 AM


New To Site? Need Help?

All times are GMT. The time now is 05:09 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