current limit help

Posted by: Anjana Salgaonkar on 03/11/2015

Hi.....

I have designed smps of 30Watt of input range 40 to 100Vdc using TOP-HX. I want to know how PI-Expert calculate current limit and power limit of particular design? Please explain using example.

Comments

Thanks for Posting your question into forum. The PI expert calculate current limit based on the size of the devices you are using. Please go through our TopSwitch Application note.
Regards,
PI-KSAN

thanks KSAN i will go through it throughly......:)

i m using LCR meter(max freq. 10KHz) to measure inductance of transformer which is operating at 132KHz......is this the basic reason for transformer suggested by PIexpert is not working for my circuit? please suggets any other inductance measurement procedure.

Thanks for Posting your question into forum. We are having tough time to understand your question, Is PI Expert Suggested Transformer not working on your design? You cannot measure inductance of the transformer with 10KHz LCR Meter. Could you please explain what are the issues that you are encountering?

Regards,

PI-KSAN

yeah.... transofrmer is not working as per requirement....i have wound transformer as suggested by PI expert, values of inductance and leakage inductance are same as suggested. i m measuring primary inductance on LCR meter (APLAB 4080D) of which maximum frequency is 10KHz. i m using 132KHz switching frequency for top switch 258YN. here is attching the PI design.

Attachment	Size
TOPSwitch-HX_PIDesign1.uds (347.5 KB)	347.5 KB

Thanks for Posting. We couldn't understand transformer is not working as per requirement?Could you explain what does it mean?Is your power supply not working?You cannot measure the transformer inductancr with 10KHz LCR Meter. Could you clearly explain what are your trying to do? What are the issues that you encountered?PI Expert says design passed.

Regards,

PI-KSAN