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  1. #1
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    How this SMPS works?

    I tried to get the schematic from this SMPS Board

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    and got this

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    But I didn't understand the working of this schematic, I don't want to go too much deep.. (But It is also welcome)
    1. How these NPN and PNP transistors are configured to drive the Mosfet?
    2. How can one increase the power output from this SMPS, say it is built for 2A supply, How to increase it to further more to 5A(say).

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  2. #2
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    barry's Avatar
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    Re: How this SMPS works?

    That's a pretty vague question. When the NPN turns on, it pulls the base of the PNP lower, turning it on. The collector of the PNP drives the voltage to the MOSFET gate.

    If you want more current out of this you're going to have to change the MOSFET and transformer.


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  3. #3
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    Re: How this SMPS works?

    And how the base of this NPN receives pulse and how the frequency or duty cycle of this MOSFET gets affected?



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  4. #4
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    Re: How this SMPS works?

    I suggest you may have drawn it out just a little bit mixed up ....



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