Winding EE16 High Frequency Transformer

[mcmsat]

I have to admit my difficulties whenever high frequency transformers are involved in my project!

Please I want those who know their way with ferrite winding to assist me with this EE16 winding.

Though the power is not needed for high precision but core saturation will not be tolerated.

Below are the parameters for the SMPS

AC Input Min = 85V

AC Input Max = 265V

AC Input Frequency = 50Hz

PWM Controller IC = NCP1200

OScilation Fequency = 100KHz

Output Voltage = 14VDC

Output (I) continous = 800mA

Duty cycle Max = 87%

Core = EE16 See the Attached picture for the trafo parameters



The power does not need isolation. The optocoupler is easier for me to use but it is not used for isolation.
Below is the schematic diagram of the SMPS.

 

[Silvio]

I suggest you contact Starichok51 in the tread CALCULATION PROGRAMS FOR TRANSFORMERS AND INDUCTORS

Regards, Silvio

 

[Chris_C]

Hi.

I would think that multiple strands of small gauge wire, like Litz would work. Or what I do is twist 4 or 5 smaller gauge like 36 or 32 lightly, just to hold together to avoid skin effect at 100KHz. Parallel multiple strains of 'strains' for higher current.
This photo is of one of my first SMPS projects.....that worked. I am new to SMPS, and my next challenge awaits.:adoration: Here, I used the strain of strains method for the small toroid, Epcos N87, 115KHz, 3+3 || 8+8, 51.26mmSq

Would foil be an option for your transfo?

 

[Silvio]

Hi.

I would think that multiple strands of small gauge wire, like Litz would work. Or what I do is twist 4 or 5 smaller gauge like 36 or 32 lightly, just to hold together to avoid skin effect at 100KHz. Parallel multiple strains of 'strains' for higher current.
This photo is of one of my first SMPS projects.....that worked. I am new to SMPS, and my next challenge awaits.:adoration: Here, I used the strain of strains method for the small toroid, Epcos N87, 115KHz, 3+3 || 8+8, 51.26m mmSq

Would foil be an option for your transfo?

Please specify what currents are you talking of in the primary and secondary windings. Please also specify the duty cycle of the smps as there is a difference in a power supply delivering full current all the time then another having say 50% duty.

Knowing this we can work out what is the best wire or foil to use.

I suggest you read the blog post Making Litz wire at home so that you can understand more about the subject.

Regards Silvio

 

[mcmsat]

OK thanks Pals, I have use the Excel sheet Transformer Calculator and it solved my problems. I am using it for high frequency transformer winding and it's not dissappointed me. Thanks.

 

[mcmsat]

Hello Silvio, please can you send me a link where I can buy those foils used in high frequency transformer winding which are normally insulated with a yellow adhesive tape?

 

[Silvio]

@mcmsat

Hi I do not think you can buy readily made insulated copper foil tape, however you can purchase copper foil which is available in various thicknesses. The ones usually used is 0.1mm, 0.2mm and 0.3mm. These sheets of copper can be cut to size with a normal scissors.
Insulation mylar tape can be stuck on one or both sides. However the mylar tape being a bit thin it is advisable to put 2 layers of tape on each strip of copper.
Mylar tape is a special tape used for transformer winding. This tape can withstand high temperature up to around 150 degrees Celsius and not loosing its properties in any way. Mylar tape exist in various widths and can be purchased on E-Bay or Aliexpress. Copper foil sheet also can be purchased on E-Bay and here are a few links. You can look further for other thicknesses and sizes.

https://www.ebay.co.uk/itm/99-9-Pur...026258?hash=item1ec891f012:g:ZZoAAOSwy3NZYypu

https://www.ebay.co.uk/itm/30mm-Wid...310761&hash=item44100ff1ea:g:oYEAAOSwrhhaRGko

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20180203091253&SearchText=tawny+tape

https://www.aliexpress.com/item/1pc...d49d-4f22-a276-df13750bd3a4&priceBeautifyAB=0


Regards Silvio

 

[mcmsat]

Thanks Silvio, I now understand. It's because they are displayed without the myler tape that made me not to recognize them on Aliexpress. I buy all my components from Aliexpress.
Thanks Again.