Newbe Question: ESL bias 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 5th June 2011, 04:26 PM   #1
diyAudio Member
 
Join Date: Sep 2010
Default Newbe Question: ESL bias power supply

I am gearing up to building a set of ESL loosely based on Jazzman’s construction techniques, utilizing the D/S of 1/16’ spacing of the C 6 um film under high tesnion. I will ultimately have the stators powder coated.

My question is: how much power is optimum to run these panels at nominal to higher volumes (and I know this is subjective). The second question is in regards to the bias power supply. I would like to have the flexibility of a variable power supply described by Mark Rehorst http://mark.rehorst.com/ESLs/esl_bias_supply.html however, the question: Is it possible to use the variable low voltage section of the circuit (ran in parallel with C-3) to feed another EMCO G-40 module ultimately to supply bias power to the other panel. My thoughts are that this would supply equal and variable bias power to both panels simultaneously? Can one module supply bias power to both panels, or do I really need to build two power supplies?

Thanks In advance,
Jerry
  Reply With Quote
Old 5th June 2011, 06:13 PM   #2
diyAudio Member
 
Join Date: Sep 2010
I forgot to mention that the proposed sizes of the panel will be 18x48".
  Reply With Quote
Old 5th June 2011, 07:06 PM   #3
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
Yes, you can use one bias supply.
But you must use a atleast a 10meg ohm or greater in series with the diagrham lead and also feeding the stepup transformer center tap other wise you will get crosstalk between the two panels and this will hurt your stereo imaging.

Once you get your panels up and running try it and you will see what I mean.
The resistors values can be found experimently.

But it is best to have seperate supply's so that the transformers can be kept close to the panels so that you don't have any wires with high tension on them lying on the floor as the voltage can creep into other pieces of equipment.

I have had this happen luckily I didn't lose any thing but I did lose one of my little woofers once when a hightension feed line got too close the wire feeding the woofer and pop the voice coil.

jer
  Reply With Quote
Old 5th June 2011, 07:15 PM   #4
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
Besides the crosstalk I once wired up three of my panels together on one chanel using my variable supply and by Just varing the voltage caused a shift in volume from one panel to another.
By adding the isolation resistor All 3 panels worked in unison at the same volume level when the bias voltage was varied.


jer
  Reply With Quote
Old 5th June 2011, 09:13 PM   #5
diyAudio Member
 
Join Date: Sep 2010
Thanks for that advice Jer,

Can I ask what size/area panel, and D/S distance spacing are you using for the bias voltage?

Thanks,
Jerry
  Reply With Quote
Old 5th June 2011, 10:21 PM   #6
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
right now I am using my little panels of 3.25" X 9.75" diagphram size with a d/s of around .070" to .075" (i think it was .072").

this is the exploded view and a close up of the stator.


jer
Attached Images
File Type: jpg ready%20to%20be%20bolted%20back%20together.jpg (43.7 KB, 156 views)
File Type: jpg P1120327.JPG (79.0 KB, 151 views)

Last edited by geraldfryjr; 5th June 2011 at 10:27 PM.
  Reply With Quote
Old 5th June 2011, 10:51 PM   #7
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
here is some more pics and the setup I was referring to.


Material for ESL

There are a bunch more.
I guess I need to take the time and recompile my list of links and put it in the permenent thread.

How to construct a cube louver (Acoustat)

ESL Diaphragm coating
jer

Last edited by geraldfryjr; 5th June 2011 at 10:59 PM.
  Reply With Quote
Old 6th June 2011, 04:33 AM   #8
diyAudio Member
 
chinsettawong's Avatar
 
Join Date: Jun 2006
Hi Dochungwell,

To make a pair of hybrid ESL, following what Jazzman's construction technics can't go wrong. About the spacer thickness, I think 1 to 1.5 millimeters is good enough. The bias voltage can be around 2-2.5KV for each 1 mm.

Good luck.

Wachara C.
  Reply With Quote
Old 6th June 2011, 05:33 AM   #9
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
I also have a newbee question :

How do you test the output voltage ?
I tried even with a 10M high voltage probe.
It still overloads the circuit too much, that I get nowhere near the 2kV i expected.


Thx,
Patrick
  Reply With Quote
Old 6th June 2011, 05:51 AM   #10
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

10Meg is the typical impedance of a multimeter and way too low to measure HV of a Bias supply. The currents are too large and the load forces the voltage down. For measuring HV think of impedance values in the Giga-range. Simplest is to solder a chain of 100 pcs of 10Meg resistors and measure the voltage over one or a couple of the ´lowest´ resistors and calculate the voltage after the resistor-divider-formula Vmes=Vbias*Rmes/Rcomplete (with Rmes beeing the parallel from the resistor measured over and the multimeters internal impedance).
This method doesn´t give exact values, but You are close enough.

jauu
Calvin
  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
ESL bias supply the GE way jfitz57 Planars & Exotics 22 30th May 2011 11:00 PM
Cheap ESL bias supply parts I_Forgot Planars & Exotics 8 16th January 2011 01:28 AM
ESL Bias Supply Polarity bolserst Planars & Exotics 30 23rd June 2010 01:38 AM
Newbe question about power chips Musiclear Solid State 2 17th November 2006 07:51 PM
Could someone explain the ESL High Voltage DC bias supply to me? jzh797s Planars & Exotics 4 25th August 2006 04:19 AM


New To Site? Need Help?

All times are GMT. The time now is 11:15 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