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Type: Posts; User: yoosefheidar

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  1. Replies
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    it seems at first step i should replace secondary...

    it seems at first step i should replace secondary winding with copper sheet to see what happend.hope that solves snubber problem!
    in case of increase freq you right switching losses goes up but...
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    thank you again i going to use copper sheet...

    thank you again
    i going to use copper sheet instead of round wire for test
    i think about another way:increase freqquency to 100 KHz and reduce primary turn to 12 and then reduce secondary turns to...
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    thank you very much Silvio wire is made of one...

    thank you very much Silvio
    wire is made of one bundle of 22 strands.but they are not parallel and they wrapped together so for example in one strand current sometimes is in center of bundle and...
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    Problem with half bridge

    HI
    I use this schematic for a 700 watt power supply.output voltage is 36v and current is 20amps.the core is etd44/freq is 50KHZ/primary is 30 turns litz(6*0.55)/secondary is 9 turns litz(22*0.55)...
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    400w current-mode boost UC3845

    hi
    i design this circuit and build it.under no load condition input is 15 and output is 36 without problem.but when i connetct a 6 ohm load out put voltage drop to about 14.5v and output current...
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    i will try this to see what is result. why...

    i will try this to see what is result.
    why without feedback trafo don't have that sound at all?
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    i have two 5K resistor in output.it is about 0/5...

    i have two 5K resistor in output.it is about 0/5 watt.i didn't try smps with a load to check trafo sound.
    unfortunately i dont't have a scope and just use MATLAB for seeing wave forms.
    now duty...
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    hi Silvio i use that feedback in my smps, but...

    hi Silvio
    i use that feedback in my smps, but transformer sound become worse!(voltage changes become better and vary beetwen 92 to 94)
    listen to transformer sound in this link:...
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    best working temp for a pc40 core is about 90 deg...

    best working temp for a pc40 core is about 90 deg because at this temp core losses is minimum
    so 60-80 deg is normal for ferrite core.
    in my smps with 19 turns in transformer primary core temp is...
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    designing a good feedback is very complicated....

    designing a good feedback is very complicated.
    for a good feedback we need to calculate poles/zeros/bode plots/phase margin/gain margin/transient response and other parameters.
    so i should use this...
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    i have a question can you explain how exactly...

    i have a question
    can you explain how exactly this feed back work when output voltage is under or over target voltage?i need part by part(feedback) explanation at opto diode side and transistor side
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    thank you very much Silvio this pdf helps me...

    thank you very much Silvio
    this pdf helps me very much and now i should calculate feedback resistors and capacitors and compensation parts based my circuit parts

    about R14 i think that is correct...
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    1-there is no problem with core saturation or...

    1-there is no problem with core saturation or primary winding.the core works at 2000 guass and even can work at 5000 guass without saturation(pc40 material)core didn't get warm and transfer power...
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    hi 1-I calculate primary by "V=4NFBA" formula...

    hi
    1-I calculate primary by "V=4NFBA" formula
    2-my input voltage is 220VAC
    3-my smps works fine without feedback and i connect a 300 watt load and voltage droped about 20 volt which is normal....
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    sg3525/ir2110 half bridge

    hi everyone
    i use this schematic to build a half bridge power supply.
    but i have some problems and need some helps.
    first problem is feedback.i think this feedback is not good beacause whit this...
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