A green and clean environment is a human right!

Projects by members => Projects by members => Sebosfato => Topic started by: sebosfato on July 30, 2014, 04:13:12 am

Title: Learning
Post by: Login to see usernames on July 30, 2014, 04:13:12 am

Today i learned more about power and switching transformers, how to design and understand its losses and capabilities...

http://ludens.cl/Electron/trafos/trafos.html

http://ludens.cl/Electron/Magnet.html

Title: Re: Learning
Post by: Login to see usernames on July 30, 2014, 04:32:09 am

I found that the aluminum case covering up the vic improves coupling and is a technic for doing that which consists of adding a shorted conductive foil around the core.. this contains the field inside... 

https://www.youtube.com/watch?v=3b8Wol-X4tE

look the common mode
https://www.youtube.com/watch?v=6681mgFNomc

Title: Re: Learning
Post by: Login to see usernames on July 30, 2014, 05:55:23 am

https://www.youtube.com/watch?v=-GgB03vlNzU

how to make your own transformer...

this video teaches strange formulas that seems to work well ... including the power handling of the transformer and section of the wires...

the area of the core according to this video should be equivalent to the square root maximum power at the primary at full load, that is the maximum power developed in the secondary divided the efficiency percentage in decimal numbers..

It ends up with what seems a well sized transformer...

here some lamination power http://www.construyasuvideorockola.com/transformador.php

 

Title: Re: Learning
Post by: Login to see usernames on July 30, 2014, 09:19:45 am

Thank you, Fabio.
Great stuff :-)

Title: Re: Learning
Post by: Login to see usernames on July 30, 2014, 12:41:51 pm

Your Welcome Bro!

check this... the case information i took out of one of this books in attachment

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 10:41:35 am

And do not forget the option of airgaps...

http://m.powerelectronics.com/content/why-have-air-gap
http://electronics.stackexchange.com/questions/77797/why-is-flyback-air-gap-needed-for-energy-storage

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 10:45:40 am

The term "Flyback Transformer" is a little misleading and its more useful to consider it as coupled inductors rather than a transformer because the action is quite different with a conventional transformer energy is going into the primary and out of the secondary at the same time it does not store energy. With a "Flyback" transformer energy is first stored then released.

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 10:47:11 am

The energy storage is therefore only possible in the air gap and is proportional to be air gap volume and the square of the flux density.

☺

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 10:50:29 am

Strictly speaking you can store some energy without the air gap but the permeability of magnetic materials such as ferrite is so much higher than free space that energy storage is negligible in the magnetic material. The gap does not have to be air just non-magnetic and it can be distributed into a number separate gaps, including microscopic ones.

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 11:02:03 am

http://info.ee.surrey.ac.uk/Workshop/advice/coils/gap/

nice info.....

Title: Re: Learning
Post by: Login to see usernames on July 31, 2014, 15:27:16 pm

Yes bro the gap is a way for tunning the transformer to the power you want it to have... since the flux gets unchanged while you gap it the gap can reduce the inductance without reducing the flux but extending the flux that can be handled by the core. 

this is just as you said you can control the energy of the flyback pulse.

good one! great links too! thanks Steve