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    push pull ac-dc auxiliary winding.

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    what's the purpose of the (N2 + N3) center-tape winding in push pull Ac-Dc converter

    as shown in above schematic. is it a kick start auxiliary winding? if not

    how to start the smps oscillator without external power kit?

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    Re: push pull ac-dc auxiliary winding.

    Auxiliary power supply once the push pull starts - what powers the chip to provide the gate drive at cold start is not shown / not drawn / not provided in the schematic - likely an unfinished "design" ...



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    Re: push pull ac-dc auxiliary winding.

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    that's the complete schematic of the push pull AC to DC converter taken from

    powerEsim. i didn't understand the purpose of (N2 + N3) winding here in the schematic? is it the power to the

    gate driver pwm block?



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    Re: push pull ac-dc auxiliary winding.

    Using the winding only to power the feedback opto coupler doesn't make sense.

    But I presume you can read schematics good enough to see that the driver power supply is not shown in the drawing. That's more a functional block diagram than a real schematic.



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    Re: push pull ac-dc auxiliary winding.

    i see that the driver power supply is not shown here in schematic also the winding (N2 + N3) doesn't make sense.

    that's why i ask the question. but unfortunately i don't have another schematic of push pull ac dc.

    that's the complete schematic and know they only show a functional block rather instead of

    the gate driver pwm ic. but if to power the push pull gate driver without using external power

    can we use a kick start resistor with auxiliary winding?



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    Re: push pull ac-dc auxiliary winding.

    Yes, that's what Easy peasy suggested.


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    Re: push pull ac-dc auxiliary winding.

    also note if you are rectifying 230V mains the push pull fets will see > 650Volts - so 800V min required ...



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