Hello Wachara,
Here is the method I made up for testing the conductive surface of my diaphragms :
"Mousse conductrice" is a piece of conductive foam (used to package CMOS chips)
"Luciole néon" is a miniature 60 to 80 volts neon light
"Alim H.T." is a high voltage source (my Fluke model 407, 550 VDC power supply)
+ 2 crocodiles clips and a high value resistor (10 M) for security
Connect the crocodile clip to the copper surface of the diaphragm frame and touch the diaphragm conductive surface with the piece of conductive foam. If the neon lights on with constant intensity at anyplace on the diaphragm surface, then the diaphragm is OK.
Philippe
Here is the method I made up for testing the conductive surface of my diaphragms :
An externally hosted image should be here but it was not working when we last tested it.
"Mousse conductrice" is a piece of conductive foam (used to package CMOS chips)
"Luciole néon" is a miniature 60 to 80 volts neon light
"Alim H.T." is a high voltage source (my Fluke model 407, 550 VDC power supply)
+ 2 crocodiles clips and a high value resistor (10 M) for security
Connect the crocodile clip to the copper surface of the diaphragm frame and touch the diaphragm conductive surface with the piece of conductive foam. If the neon lights on with constant intensity at anyplace on the diaphragm surface, then the diaphragm is OK.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Philippe
fwiw I found a supplier of Aquadag in the UK;
http://www.abbey-chemicals.co.uk/index.php?main_page=product_info&cPath=1_2&products_id=43
http://www.abbey-chemicals.co.uk/index.php?main_page=product_info&cPath=1_2&products_id=43
Hi Vaughn,
Do you mean where I get my 1.4 and 0.9 micron mylar from? The link is here: www.indoorspecialties.com . The 1.4 is called Ultrafilm and the 0.9 is SuperUltrafilm.
And thanks for your link.
Wachara C.
Do you mean where I get my 1.4 and 0.9 micron mylar from? The link is here: www.indoorspecialties.com . The 1.4 is called Ultrafilm and the 0.9 is SuperUltrafilm.
And thanks for your link.
Wachara C.
Thanks for the mylar link Wachara. I'm not sure of the company I linked to for the Aquadag will ship outside the U.K. or not, but it might be worth a try.
Did you use a second non-stretched diaphragm as Philippe did to protect the diaphragm from moisture? Also, did you use a common two part epoxy to attach the diaphragm?
Matt
Did you use a second non-stretched diaphragm as Philippe did to protect the diaphragm from moisture? Also, did you use a common two part epoxy to attach the diaphragm?
Matt
Hi Matt,
Yes, I did make two outer rings with 11 micron film on them to protect outer sides of the stators from moisture. Without them, my sweat would go through the stator holes and shot circuit with the diaphragm. Thailand is hot.
I use 11 micron film on the outside because I feel that I get too much bass out of the 6 micron mylar diaphragm in the middle. It helps reduce the bass a little. But I might change that in the future.
Wachara C.
Yes, I did make two outer rings with 11 micron film on them to protect outer sides of the stators from moisture. Without them, my sweat would go through the stator holes and shot circuit with the diaphragm. Thailand is hot.
I use 11 micron film on the outside because I feel that I get too much bass out of the 6 micron mylar diaphragm in the middle. It helps reduce the bass a little. But I might change that in the future.
Wachara C.
Hello Wachara,
I don't use graphite powder, I know graphite powder, Aquadag (graphite colloïdal), for me it's not reliable. The conductive coating may be sticked strongly to the surface of the diaphragm because the diaphragm vibrates and is submitted to a high electrostatic field.
I use a solution of water with water-soluble acrylic varnish and carbon obtained by pyrolysis of white sugar (like caramel). Carbon may also obtained from white sugar with sulfuric acid. The coating is very thin (< 0.1 µm) and transparent.
Philippe
I don't use graphite powder, I know graphite powder, Aquadag (graphite colloïdal), for me it's not reliable. The conductive coating may be sticked strongly to the surface of the diaphragm because the diaphragm vibrates and is submitted to a high electrostatic field.
I use a solution of water with water-soluble acrylic varnish and carbon obtained by pyrolysis of white sugar (like caramel). Carbon may also obtained from white sugar with sulfuric acid. The coating is very thin (< 0.1 µm) and transparent.
Philippe
Try to use my method : acrylic water-soluble varnish + antistatic liquid. The slightly conductive coating obtained is dry and have a high electrical efficiency.
My article in "L'Audiophile" february/march 1989, sorry it's in french ! but maybe it can be interesting : http://www.amfoat.org/download/audiophile/n3casque.pdf
My electrostatic headphones with copper rods electrodes. The rods have a diameter of 1.5 mm and are spaced with 1 mm.
Philippe
My article in "L'Audiophile" february/march 1989, sorry it's in french ! but maybe it can be interesting : http://www.amfoat.org/download/audiophile/n3casque.pdf
My electrostatic headphones with copper rods electrodes. The rods have a diameter of 1.5 mm and are spaced with 1 mm.
An externally hosted image should be here but it was not working when we last tested it.
Philippe
Hi Philippe,
I want to know just how many versions of ES headphone have you made? This one with copper rod looks very interesting. How do you like it compare to the other one?
I will try to find the water soluble acrylic vanish. Have you tried to measure how much resistance you can get out of this solution? I mean how many ohm does it measure?
I'm very interested in all your works. Please show us more.
Wachara C.
I want to know just how many versions of ES headphone have you made? This one with copper rod looks very interesting. How do you like it compare to the other one?
I will try to find the water soluble acrylic vanish. Have you tried to measure how much resistance you can get out of this solution? I mean how many ohm does it measure?
I'm very interested in all your works. Please show us more.
Wachara C.
Phil47 said:
Hello Philippe
Thats sounds nice.
Could you say something about the absolute resistance and its reproducibility, cause that's where problems of carbon based stuff usually are. At a thickness of less than 0,1 micron (which is 100 nanometer) you will be 'close' to the theoretical limits regarding particle size.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.