ESL electronics 101 for the electronics challenged - Page 2 - 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 28th April 2011, 08:36 AM   #11
oshifis is offline oshifis  Hungary
diyAudio Member
 
Join Date: Mar 2004
Location: Budapest, Hungary
Check also Quad ESL Dummy Load
  Reply With Quote
Old 29th April 2011, 12:23 AM   #12
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by markusA View Post
Very cool spreadsheet.
The model for a transformer driven ESL sounds interesting.
Ok. I'll see if I can dig it up tonight, or tomorrow.
  Reply With Quote
Old 29th April 2011, 05:19 PM   #13
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by markusA View Post
Very cool spreadsheet.
The model for a transformer driven ESL sounds interesting.
Attached is a *.zip file containing an Excel 2004 compatible and Excel 2007+ compatible spreadsheet for modeling impedance and response of an ESL connected to a step-up transformer. Also attached is the specification sheet for the Plitron 4314 transformer which I will post a couple sample calculations for.

Lower left plot shows impedance magnitude and phase.
Lower right plot shows normalized output response of voltage applied to ESL stators.
Upper right plot shows the impedance vector diagram for marker frequency.

Note that Rc(core losses) and Lp(primary inductance) are in reality a function of input voltage magnitude and frequency. In this spreadsheet they are constants. So not perfect modeling, but pretty good. Rc is not specified in the Plitron data. I estimated it at 500 ohm. This sets the peak magnitude of the impedance peak for the parallel resonance between Lp and (Cw + Cesl)*N^2.

Pic #1: Plitron 4314 with 1000pF ESL and recommended Rdamp = 0.8 ohm
You can see that the impedance and response match well with page 2 of the Plitron data sheet.

Pic #2: Plitron 4314 with 1000pF ESL and Rdamp = 0.2 ohm
The recommend value of 0.8 ohm gives you a maximally flat HF electrical response(stator voltages). If a lower value is chosen for Rdamp, the under-damped series resonance between LL and (Cw + Cesl)*N^2 causes a peak in the HF response. Also note that HF impedance drops and the phase angle gets even more negative (ie capacitive) in the top two octaves.

Pic #3: Plitron 4314 with 1000pF ESL and Rdamp = 1.5 ohm
If a higher value is chosen (Rdamp = 1.5 ohm) the HF electrical response droops a bit. But, since the native response of an ESL is a rising response (+3dB/oct for line source, +6dB/oct for point source) this is actually closer to the value needed for a flat acoustic response. Not that the minimum impedance has risen and the phase angle is reduced.

Pic #4: Plitron 4314 with 1000pF ESL and Rdamp = 1.5 ohm, Rshunt = 16 ohm
Adding a shunt resistance before Rdamp does not change the response. But, it does make the impedance load the amplifier sees more resistive. If used, this resistor would need to be able to dissipate considerable power/heat.

Like before, the spreadsheet does use complex variable functions, so you will need to load the Analysis Toolpak Addin before it will work properly.
Attached Images
File Type: jpg ESL_4314_pic_01.jpg (465.5 KB, 113 views)
File Type: jpg ESL_4314_pic_02.jpg (470.0 KB, 113 views)
File Type: jpg ESL_4314_pic_03.jpg (467.8 KB, 112 views)
File Type: jpg ESL_4314_pic_04.jpg (465.8 KB, 110 views)
Attached Files
File Type: zip ESL_Z_dB_model.zip (204.7 KB, 38 views)
File Type: zip plitron_pat4134-ES.zip (410.2 KB, 31 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
esl electronics kit? taichiguy Planars & Exotics 6 26th March 2006 08:27 PM
I know [almost] nothing about electronics MetalDemonics30 Parts 2 6th May 2004 10:29 AM
Applied Audio Electronics 101-201 rick57 Solid State 5 16th May 2003 05:01 AM
B.K. Electronics ogp Solid State 2 19th November 2001 08:00 PM


New To Site? Need Help?

All times are GMT. The time now is 01:43 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