How derive the formula of distribution capacitance

none can put down the formula?

oh. I shall give it out next.

its regret

It has been awhile since I last designed a transformer. I suggest you purchase a transformer design book, there were several in years past. Capacitance gets to be complex because of the voltage distribution across the wires.

You will probable also want to understand how to calculate leakage inductance.

A good reference book on this topic is found in the old MIT Radar Handbook series developed during WWII. I think it is found in volume 5.

Is that it? Couldn't you spice it up a bit? You know what I'm sayin' ? Give it a little pizazz...know what I mean, wink, wink, nudge, nudge! Or should that be nudge, nudge, wink, wink? Who cares? Go for it!

you are quit right, next step I wish to get the derivation of leakage inductance as well. I know it more difficult than deriving capacitance. although some software can do it.

countless transformer design books in bookstore, but most of them havent deat with the problem, only jjust show you formula.( some of them are wrong)

Some of them can be derived from electromagnetics, another I cannt derive, that why I hope to get help here.

wwII has pasted more than half century. I still cannt calculate this basic formulas.

Sorry CNpower, in practice it would be very difficult to calculate but easy to measure...

Due to how the coils are wound and positioned together with the dielectric of the insulator used... I have thought about this over the weekend and don't recall ever having someone calculate this figure only to measure it, or reduce it to as little as possible by putting a ground/earth winding inbetween the two windings...

John.

John, I agree to the idea, measure is easy for getting its value.

Once you comprehend their meaning, you can improve tech. shield can reduce some distribution cap, but some of them cannt be reduce by the method.

the cap depend on the wound method. there are many wound method to make a good transformer( I mean special transformer). I know the method, but forget them for long not touching with it.

oh, the next question, I shal ask is

How do you measure industance of a transformer?

bridge? do you trust the measure value?

In a gauge meeting, I use several factories' industance bridge to meaue a tranformer, but get very different values( include import instrument). none manufactureer give me a satisfactory answer.

its very long time ago. I almost forget it.

how do you test it? by the way

Hi CNPOWER, BigBird here

I have two editions of "Electronic Transformers and Circuit" which have the derivation of the capacitance and inductance. The 1947 version by Reuben Lee and the 1988 third edition by Reuben Lee, Leo Wilson and Charles E Carter - ISBN 0-471-81976-X.

Publisher - John Wiley & Sons, Inc.

We are transformer manufacturers and use these two editions as a "Bible". Unfortunately a lot of what is in the first edition has been left out of the third edition, but see if you can find it at Amazon - where I got the 3rd edition.

I hope this helps.

Bigbird

Bigbird, thank you.

I dont know the book, it must be a valuable. as well as top #2 reference of radar handbook.

In fact, I have the derivation procedure, but I forget where I put it. its long time ago, It can be derivted by staticelectrics. I try when i m free.

because last year, I faced with making a small size transformer. worker made one by one. but it was s always broken down inside somewhere. its very diapear,

From waveform, I found it had large energy loss, and cannt calculate where the energy lost. the output efficient has only 0.6.

I refer to several wind method. cannt improve any more. I give up.my test condition is poor and enlarge it size at last.

I get it.

it hasnt derivation.

I work out it now.

I find its our certain authority reference book print a wrong formula, it lost a voltage symbol, this bother me for a long time.

My derivation is as same as above English reference book.

Regards !

I am astonished about how the Forums' Group is selected ?

The Ghoup is << Communications & Electronics >> & the subject is about Transformer's distributed capacitance?

I think most will agree that Transformers are dealt with in << Electrical Engineering >>.

In << Communications >> it is the <<distributed capacitance >> of transmission Lines [ & Feeders ]

I request 'Moderator' to see into it. Electronic Forums are being discussed in < Electrical Engineering >

Some examples:

1. Electronics Group

Oscillator from a differential output amp <http://globalspec.ip09.com/rd/9z1zrn15sbj2u45saf0snf1805nndnlq855mfnknti0>

Electrical Engineering

2. Communication Group

<http://globalspec.ip09.com/rd/9z1zelbvk4vggsqtabg2pl2c0joojdbg8nhoqbcheb8>

http://cr4.globalspec.com/thread/18470/Cell-Phone-Battery-Terminals?frmtrk=CR4digest

| Electrical Engineering | Cell Phone Battery Terminals

etc etc

I came across a discussion topic named " xxxxxnnxx ' i where actually 'mm' was mis-spelt by the 'poster'

Thanks.

You are really wrong. indeed.

What I select the column to post the thead is right. no problem

Do remember, transformer is not only belong electric but belong to electronic. In fact, in electronic circuit, you hardly can not find its figure. they are everywhere in elctronic field. They are very important part in elelcgtronics.

Dont think that electronics is only composed of resistor, capacitor or inductor and semiconductors etc. If there is no transiftor there will be no communication.

We can discuss the transformer either at elelctric or at elelctronic, they have differnent usege.

we can divide transformer into electric power and elelctronic approximately.