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wave distortion in hiperlcs400w

Posted by: mehdi22@gmail.com on

Hi

I have builded a llc400w with lcs708.

my primary current waveform is pure sinosuid in full load in advance but after 10 seccond my waveform

confrom with distortion and because of zvs losses after 20 s my ic otp shuts down ic.

thanks for any reply.

 

Comments

Submitted by PI-Tucker on 05/11/2015

I need to see waveforms and schematic.

Submitted by mehdi22@gmail.com on 05/14/2015

Hi

Because of my low leakage transformer i had added a 20 uH self to my trans as Lleakage and i

found this distortion is because of overheating of my self core and decreasing permiability in hot temperature

and i added a fan and my problem of distortion is solved.my self is wounded based on pixls.

please guide me in selecting a core with low core loss.

Thanks for any reply. 

 

Submitted by PI-Tucker on 05/15/2015

What is your switching frequency?
What was your original peak flux density?
What wire did you use?

Submitted by mehdi22@gmail.com on 06/10/2015

Hi

in my privious circuit that i explained my switching frequency is 250khz,my bac is 144 mt

and my wire is litz but my circuit had problem of transformer heathening and thus incresing frequency,

my core was pq40/40 pc40 from chineese tydz.

i changed my core with 47mm mpp toroid with no problem of heating but frequency increased again

from 250 to 350 and suddenly my ic blowed.maybe reason of ic blowing is power train invertion,i cant

understand.

Thanks for any reply

 

 

Submitted by mehdi22@gmail.com on 06/10/2015

Hi

in my privious circuit that i explained my switching frequency is 250khz,my bac is 144 mt

and my wire is litz but my circuit had problem of transformer heathening and thus incresing frequency,

my core was pq40/40 pc40 from chineese tydz.

i changed my core with 47mm mpp toroid with no problem of heating but frequency increased again

from 250 to 350 and suddenly my ic blowed.maybe reason of ic blowing is power train invertion,i cant

understand.

Thanks for any reply

 

 

Submitted by mehdi22@gmail.com on 06/10/2015

and this is my ic image

Attachment Size
WP_20150610_001[1].jpg 2.68 MB

Hi

I attached image because maybe you understand reason of ic exploding.i said maybe this is because of

hb voltage slew rate.

may you help me?

Thanks

Submitted by PI-Tucker on 06/26/2015

Pls. post a photo and construction details of your transformer and 20 uH choke.