Transformer for TNY275PN
Hello,
For a project I need to design a extremely small power supply.
I made use of PI expert online but I am unsure if the transformer I intend to use will work.
I intend to use 7491181012 from Wurth because of its size. The schematic can be foud in the attachement
It has universal AC mains input and 12V, 0.1A output.
Also there will probably not be enough copper area to act as a heatsink. Is it ok if I instead glue a heatsink with thermal glue on the IC itself?
From the schematic I am unsure where the GND on the output side is. Maybe RTN?
Thank you in advance for help.
Comments
So this is the datasheet of the transformer:
http://katalog.we-online.com/pbs/datasheet/7491181012.pdf
And in the PI Expert I get 1333uH nominal primary inductance with +-12% tolerance and 53.34uH max primary leakage.
Will this work or not?
I also have the possibility to use this transformer which is a bit larger, if the smaller one doesn't work: http://katalog.we-online.com/pbs/datas/7491182012.pdf
Which one would be better suited? I need 0.2-0,25A output current.
As for the heatsink. The isolation is not needed since all of the device will be enclosed and the only interaction will be possible through capacitive sensors.
Hello,
how much is your output current, the value you provide between the two message is different. the schematic you showed cannot deliver 0.25A current
Best Regards
As for the transformer concer, our PI experts has more design information about the design you generate. it is on the left side of your schematic. it includes the inductance you need, the wire size you need to deliver power. you can check those requirments to see if the Wurth transformer matches or not.
the GND on the out side is the RTN.
For the heatsink, does your design need isolation between parimar and secondary? if so, the heatsink will decrease the creepage from the parimary to secondary and make the isolation weaker
Best regards