Transformer wrapping

[roughshawd]

I have read alot of articles on transformer wrapping, and I am really worried about attempting to make one for a specific purpose.
That is to say that most of them talk about the linear value of the wire and that if you need more signal use more wraps, if you want more power use bigger wire(or something like that). What's bugging me most about this is that it all seems like a hit and miss kind of a thing...
It feels like you just grab an insulated wire of the right guage, spin it up on a bobbin and drop it on the E-frame, then test it, to see if you got it or not !!!!
That bothers me when I am using lightning bolts and studs for source, but not as much with the mains on my recepticals...
Is there a good experiment I can do to help get me started in this auspicious 'wrap and go' part of primary and induction?

 

[Bluejets]

I can assure you, the theory behind the details of transformer construction is not hit and miss.
Unless of course you rely on instructables etc. to source the theory.

Over 1,000 books in the link below, take your pick.
https://www.amazon.com/Electrical-Transformers-Books/s?k=Electrical+Transformers&rh=n:283155

 

[Minder]

I have read alot of articles on transformer wrapping, and I am really worried about attempting to make one for a specific purpose.

You will be better off to calculate the (K)va you need, (IxR) , obtain a transformer of the closest suitable size, then add or subtract turns as required.
If you are just wanting a low voltage custom secondary voltage of a certain value, by far the easiest to modify is the toroidal type.
To find out the turns/volt, place a small 10 turn temporary winding on and measure the voltage.

 

[bertus]

Hello,

The EDUCYPEDIA has also a couple of pages with links:
Transformers
Transformer types

Bertus

 

[roughshawd]

Here you go!
Assuming there.are no ideal circuits, and the saturation point of a coil is instant, common sense dictates that all equipment be metered. I have yet to see a built in transformer with a meter on it!

 

[roughshawd]

In replacing a melted transformer, even when I know the wire gauges, it seems kind of fundemental to count wraps! I have bundled wire on sticks up to 50 wraps on an air core with no change in voltage! So I am also assuming the primary as an exciter, and the draw on the secondary also will play a role in the current.

 

[Bluejets]

What you are saying makes no sense.

 

[roughshawd]

...when wrapping the coil, I get this image of a hammer mill with a guy cussing about the line that broke as he was spinning it on the bobbin....
I know there is electronics formulas in there somewhere...!!

 

[roughshawd]

I keep getting my finger and thumb "knummed" by the spinning coil hammer...!!
So back to the drawing board...
Is there some kind of meter experiment that can help me understand the theory behind the device?

 

[Minder]

What are you trying to describe?
On an EI style transformer ,The wire is wound on a the transformer core using a bobbin and some kind of rotary, electrical, mechanical or hand, means of winding the coil, usually with a turns counter to keep track.

 

[Martaine2005]

All the information and formulas are here.

Martin

 

[roughshawd]

Thanks Martin !! ... cant read the 10(to the ?th power) in the first formula of the write- !

But after I copy and past it here it is obviously 10-4

Calculating the Core Area (CA) of the Transformer
The Core Area is calculated through the formula given below:
CA = 1.152 ×√ (Output Voltage × Output Current)
Calculating Turns per Volt (TPV)
It is done with the following formula:
TPV = 1 / (4.44 × 10-4 × CA × Flux Density × AC frequency)
And of course, where you are, and what kind of stampings in Webers/sqr meter you are using!