inverted ESL

[WrineX]

ok ,after reading the stuff from final i thought i give it a go.

First of all i dont want to start a discussion abouit the distortion being more or less then a classic design, just want to try this more efficient way. means less stepup count.


well here first picture is the concept of the final inverter tech.

second picture is what i thought it should look like in practice. am i correct ? or do i not only change the polarity of the diodes but also switch the wires from the power so the sinus 230 looks like picture number 3. because then i have 2 opposite powers against eachother at all time. one stator is positiv and other negative?

i tried this once with my step up trafo and HS units but did not succeed, maybe my coating had to high resistance. looked like it worked only with one stator on the Hs unit.



well every comment or input is welcome, more or less destortion we might be able to still make a cheap high efficient tweeter that has less distortion then a dynamic driver.

[MJ Dijkstra]

Yes, it doesn't work at all with conventional high resistance coatings.

[geraldfryjr]

I am very interested in this technique and curious if it will work well.
I'm also wondering if Martin Logan uses the same or a similar configuration,as the schematics I have seen also use a single secondary winding.
Also a very high diagphram resistance maybe an issue with this type of configuration.
It would be very intresting to find out if any one has had any experience with this type of setup.


If you swapped the polarity on the input of hs unit 1 and flipped all of the diodes so that they are going the other direction, this would give you +hv and it would work in conjuction with hs unit 2 (a -hv) as a high voltage bipolar supply.
With the ground referenced to the input of the capacitors as the schematic shows but with the changes I had already mentioned.

[geraldfryjr]

I had bought some aluminiumized mylar once to try this technique.
Only I never got around to tryin it,but I still might as I still have the material. jer

[WrineX]

yeah so , swap the input power and the diodes?? so not like the schematic from final where only the diodes are swapped?


and yeah im gone try it with some mylar with damped aluminium on it as well, if i can get it somewhere in the netherlands.

with my high res coating the sound whas nothing !! only when i used one of the HS units there whas a little bit of sound, and with both turned on i only heared a 50 hertz buzz.


would a coating with graphite also work ? , i know the restistance could form a low pass filter. but maybe it will create a strip for high freuqency's near the copper strip to allow high frequencys only. so you dont need to sigment. other thing i whas looking for is using the alu mylar and then use S39 an accid used to solder metal,, to ereace some of the aluminium to segment the membrane.

[geraldfryjr]

I'm not sure what you mean with the graphite?
The aluminium has such a low resistance I don,t think it would make any difference.
To remove any aluminium from the surface just use a weak solution of sodium hydroxide (lye).
Just as would do too etch a pc board, as lye will clean but not etch copper just in case you were wondring. jer

[bolserst]

Originally Posted by WrineX

yeah so , swap the input power and the diodes?? so not like the schematic from final where only the diodes are swapped?
and yeah im gone try it with some mylar with damped aluminium on it as well, if i can get it somewhere in the netherlands.
with my high res coating the sound whas nothing !! only when i used one of the HS units there whas a little bit of sound, and with both turned on i only heared a 50 hertz buzz.

See Figure 4 from the Final Patent (US7054456) for correct way to orient the diodes in the two HV supplies to get + and - polarities on the stators.
Also notice they have a low pass filter on both of the supplies (10M resistor and 4nF capacitor) to reduce hum level.

[geraldfryjr]

Execellent,Steve!
Now I need to come up with a 10kv to 15kv filter cap for my supply. jer

[david yost]

What is the point of using 3 power transformers in series if the end result is essentially wall voltage into the HV board?

[WrineX]

in my image its two for the hs and one for audio. the 2 in the hs is because its a save current , you can leave those 2 away if you like but it aint as save as this ! first transforms from, 230 to 12 volt and the second 12 volt to 230, but because the transformers is limited in current its save.