Designing an output transformer using a power toroidal transformer

[Chace]

Mr. golfnut's ESL is an aluminum frame. It's sturdy, beautiful, and looks great.
10 years after completion Has there been any trouble?
Eight toroidals are stacked. Basically, is it better to stack and use?
What do you think of the idea of stacking toroidals in pairs to line up six?

I'm not sure if the recommended SET3 can connect and line up 12 toroids.
However, it is a good opportunity. I will try!

I am reading golfnut's post below.
https://www.diyaudio.com/community/threads/esl-transformer.55950/#post-5351746
I used the following calculator to consider problems 1 and 2.
[Capacitance calculation] https://www.omnicalculator.com/physics/capacitance
[RC low pass filter calculation] https://www.omnicalculator.com/physics/low-pass-filter
[LC resonant circuit calculation] https://www.omnicalculator.com/physics/resonant-frequency-lc

Consider the following topic.
1600mm(H) x 160mm(W), d/s = 3mm, step up ratio = 1:150
first problem 1
1600x160 = 256000mm^2
Capacitance = 0.755541nF
1x150x150 = 22500ohms
Cutoff frequency = 9362Hz
Cannot be used in non-segments.

Since the load capacity is about 1/20 when the resistance segment is used, the area is 1/20.
256000/20 = 12800mm^2
Capacitance = 0.0377771nF
Cutoff frequency = 187244Hz
It has become negligible.

Then problem 2
The amplifier and speaker cords are considered to be 5uH as they are.
5x150x150 = 112.5mH
Capacitance = 0.755541nF
17263Hz
There is a problem with non-segment.
Capacitance = 0.0377771nF
77202Hz
negligible range.
I think I understand the relationship between non-segment, resistive segment, step-up ratio and cut-off frequency.
I would like to know how to select a toroidal rated power. It may be useless if I myself do not study about transformers.
Is there a formula to find the diaphragm amplitude (mm) from the frequency (Hz)?

By the way, the original article says that the cutoff frequency is 5.5kHz at a step-up ratio of 1:200.
Isn't 1nF and 200mH 11254Hz?

 

[maudio]

If you are willing to study a bit more, there is an excellent document about esl theory and design written by Mr Verwaal that will answer most of your questions. First link on this page:

http://home.kpn.nl/verwa255/esl/esl_root.html

Also highly recommended are the original documents of Peter Walker on esl design, shouldn't be too hard to find them on the web.

Btw when calculating things, you must take into account the transformators. They will add a lot of inductance and capacitance to the equation. In fact the internal capacitance of the transformer is likely higher than that of a segmented panel.

 

[Chace]

Thank you for telling us about Mr.Verwaal homepage and sentences.
The Dutch version is substantial. I'll read it little by little, even if it's only as far as I can understand.
Certainly, if the capacitance inside the transformer is larger than the ESL panel, the main premise will collapse.

 

[bentoronto]

The custom-made Dayton-Wright transformers weigh 39 lbs*, are happy at over 10kV, and seem pretty useful down to maybe 50 Hz. My belief is that these and all transformers need some input shaping for EQ and impedance control (at both extremes of the frequency compass to keep amps smiling).

I'm using a pair for my 1977 DIY panels and have another pair sitting around aimlessly or waiting for a new home.

Nothing sounds as good as high-voltage direct amplifiers (like my old amp based on Sanders's concepts), but these come close.

Ben
*each

 

[Chace]

Hello Mr bentoronto,
I didn't know Dayton-Wright ESL.
Dayton-Wright step-up transformer was very large and heavy!
It may be a shortcut to take it out of the manufacturer's product and reuse it.
1977! ? It is a durable panel that can be used for a long time. wonderful!

Personally, my goal is an ESL that can be built from commonly available parts.

 

[bentoronto]

I know somebody who has 4 Dayton-Wright 39 lb full-range transformers for sale including a schematic of the "massaging" circuitry Mike Wright used.