Alternative step-up Transformer?

[enilsen]

Does anyone or has anyone done any research into the use of a High-Power Piezo electric Transformer to be used as an alternative to the traditional step-up transformer for electrostatic speakers?

I came a cross this article and thought there might be some uses for this in the audio world.

High-Power Piezoelectric Transformer

 

[v-bro]

Don't know much about this technology, but it says dc/dc, shouldn't it be ac/ac?

 

[MarkRehorst]

PTs are highly nonlinear so they aren't suitable for stepping up the audio voltage. You could use a small one to generate the HV bias...

I_F

 

[v-bro]

But than it would probably be nicer to use one of those:
http://www.emcohighvoltage.com/

(for hv supply)

 

[MarkRehorst]

But than it would probably be nicer to use one of those:
http://www.emcohighvoltage.com/
(for hv supply)

See my design here:
http://www.rehorst.com/esl/esl_bias.htm

I_F

 

[v-bro]

I_forgot, that's some really nice work!

Eventhough you're a goat, you diserve a hug!
😀 😉

I feel a photosynthesis coming up followed by some acid bathing....

 

[enilsen]

PTs are highly nonlinear so they aren't suitable for stepping up the audio voltage. You could use a small one to generate the HV bias...

Thanks for clarifying that they are nonlinear. I was intrigued with the ideal that maybe these Piezo Transformers could substitute traditional transformers. I know the layout displayed a DC to DC design, but the PT's are AC to AC and had an appeal to address problems with traditional transformers.

I know this is a long shot, but are there any other methods to create a linear AC hv voltage transformer with out using the traditional method?

 

[MarkRehorst]

I saw an article in an engineering magazine several years ago about using the photosensitivity of some high voltage rectifiers that were packaged in clear glass as a high voltage modulator. You would use the audio signal to drive an LED which would then couple to the diode(s) and modulate the voltage. I think the diodes were reverse biased and the light caused controlled leakage current, sufficient to swing a few thousand volts.

I guess it didn't work very well- I have yet to see a speaker on the market that uses that sort of circuit. Maybe the recent advances in LED output would make this sort of thing more workable...

I am in the process of updating my ESL web pages. The new stuff (and some of the old which I haven't gotten around to editing yet) is now located here: http://mark.rehorst.com/ESLs/index.htm
I will be updating everything over the next couple weeks including adding photos and drawings. When the work is done I'll be replacing the old page with a link to the new one because there are a lot of pages out there linked to mine and I'd hate to bust all those links...

I_F

 

[maudio]

Philips once constructed such an amp but it never made it out of the labs. I guess the same goes for design details

My own trials with optocouplers and DD got stuck on noise problems and instability due to capacitive coupling. Even through 0.5pf there's enough coupling to mess up the tiny photocurrents.

The optocoupled rectifier would overcome this but unfortunately such components are not available. Maybe it's possible to DIY them 😎