What is the material of flyback transformer's core?

[Clarkdale44]

Hello

Just as title says, i need to know what material is used for the core of a flyback transformer.

I have heard people say its made of ferrite if yes then can i use it for making transformer, i mean winding it with magnet wire for making cfl drivers? Many people used ferrite rod found in old AM/FM radios for this purpose, so just want to confirm whether the flyback transformer's core can be used for the same purpose.


Regards!!!

 

[Nigel Goodwin]

I've always heard they were ferrite as well - but seeing as the core is used for exactly the same purposes, it's obviously perfectly suitable for a CFL driver.

 

[Clarkdale44]

I've always heard they were ferrite as well - but seeing as the core is used for exactly the same purposes, it's obviously perfectly suitable for a CFL driver.

Thanks , i am gonna try winding it.

 

[Diver300]

Flyback transformers need to store energy each cycle. The cores often have a gap to increase the stored energy. In a conventional transformer, stored energy should be minimised, so they are made with no gap.

Your flyback cores will probably not be suitable.

 

[Nigel Goodwin]

Flyback transformers need to store energy each cycle. The cores often have a gap to increase the stored energy. In a conventional transformer, stored energy should be minimised, so they are made with no gap.

Your flyback cores will probably not be suitable.

Then take the insulators (if any) out of the gap.

 

[Diver300]

Then take the insulators (if any) out of the gap.

If there are any insulators, that's fine. Unfortunately, the gaps are often made by having the sides of the core slightly longer than the middle, so there are no insulators to take out.

 

[ronsimpson]

Flyback cores are often "UU" cores. I assumed we are talking about a TV flyback cores.
The "center leg gap" is used on "EE" or "EI" cores. (not generally used for high voltage like in TV sets)
I have never seen a "outer leg gap". They are center leg capped. (if they have 3 legs)
**broken link removed****broken link removed**

 

[Nigel Goodwin]

Historically LOPTX's used the cores on the right above.

 

[dr pepper]

I have used them before, they can take a fair amount of juice as there is a lot of mm2 area, seeing as telly lopty's run at nearly 16kc they are ferrite, if you find a telly with an iron core put it back in and put it on ebay it'll be a valuable vintage set.
I've found a couple of ferrite loptys with air gaps.
You can light a cfl or fluo with a loptys secondary, google royer flyback driver, you only need to wind 8 turns or so on the backside of the lopty, I htink you can even light a cfl from a 1.5v batt.

 

[Clarkdale44]

Flyback cores are often "UU" cores. I assumed we are talking about a TV flyback cores.
The "center leg gap" is used on "EE" or "EI" cores. (not generally used for high voltage like in TV sets)
I have never seen a "outer leg gap". They are center leg capped. (if they have 3 legs)
**broken link removed****broken link removed**

The one i have is the second one from the left in the second picture.

 

[dr pepper]

There are different types of core material, and each has its own properties, if you run them similar to the freq they are used in tellys (16kc) they should be good.
This lloks like its a tv lopty core, and as you can see it can handle a lot of juice: