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Thread: Flyback SMPS transformer calculations

  1. #11
    diysmps Senior Member
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    Hi mr.silvio ,, this is a universal pwm that is sold in the market in my country ,,, and is booming among lovers of audio.mereka build it for cheap smp ... but i always fail to build it ... they can not afford up to 1000watt even ... yes if you want to give a lesson about this topology, it sounds very good. is uc3842 is same as uc3843


    And here's an example of a standard pwm and scheme among beginners
    downloadfile.jpg FB_IMG_1526400726852.jpgFB_IMG_1522899393448.jpg
    Last edited by Upik; 05-15-2018 at 04:32 PM.

  2. #12
    .... Silvio's Avatar
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    Hi Upik, All I can see is here is a way to utilize the driver and enhancing more current in the main transformer for higher current. This is achieved by adding more transistors in parallel with the output of the main pcb.
    The topology is flyback and here you only use the first quadrant of the transformer flux. This means that for a given core size you will only get say 1/2 the power compared to a half bridge.
    As you can observe it oscillates only on one direction and not changing flux in opposing directions like in push pull or half or full bridge.

    I am bit septic about the output power that can be absorbed this way, maybe 500w or so. I believe using half bridge will give more power especially if you are hoping for 1000w or so.

    Regards

    Silvio

  3. #13
    diysmps Senior Member
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    Quote Originally Posted by Silvio View Post
    Hi Upik, All I can see is here is a way to utilize the driver and enhancing more current in the main transformer for higher current. This is achieved by adding more transistors in parallel with the output of the main pcb.
    The topology is flyback and here you only use the first quadrant of the transformer flux. This means that for a given core size you will only get say 1/2 the power compared to a half bridge.
    As you can observe it oscillates only on one direction and not changing flux in opposing directions like in push pull or half or full bridge.

    I am bit septic about the output power that can be absorbed this way, maybe 500w or so. I believe using half bridge will give more power especially if you are hoping for 1000w or so.

    Regards

    Silvio

    Yes it's true mr.silvio ,,, many people in my country build it, for the reason of cheap cost. But it is rather complicated. Not many of them fail, with burning fet. The voltage voltage goes into the main transformer 300 vdc.beda with hb topology . that only takes half of the main voltage. maybe their seniors add gdt to the mosfet driver, use 2 pwm module and 2 transformer in one smp. they assume that hb topology need expensive. .silvio do you have any suggestion to utilize this pwm, (gacun) it's module name in my country.

  4. #14
    .... Silvio's Avatar
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    Quote Originally Posted by Upik View Post
    Yes it's true mr.silvio ,,, many people in my country build it, for the reason of cheap cost. But it is rather complicated. Not many of them fail, with burning fet. The voltage voltage goes into the main transformer 300 vdc.beda with hb topology . that only takes half of the main voltage. maybe their seniors add gdt to the mosfet driver, use 2 pwm module and 2 transformer in one smp. they assume that hb topology need expensive. .silvio do you have any suggestion to utilize this pwm, (gacun) it's module name in my country.
    I will design a smps in the future with a module like that using the IR2153 which incorporate a soft start and SCP for audio for around 1000w. But now I am busy working on air conditioners. In winter when the work calm down I will have more time and I do it and share it here. It will be a pin header that you can fit to the main pcb. It will have a current amplifier for switching IGBT or heavy duty fets, It can use ETD 39 for 500 to 700w and ETD 49 for 1000w or more. It is all being designed in my head for the moment but i will do it for real.

    Regards Silvio

  5. #15
    diysmps Senior Member
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    Quote Originally Posted by Silvio View Post
    I will design a smps in the future with a module like that using the IR2153 which incorporate a soft start and SCP for audio for around 1000w. But now I am busy working on air conditioners. In winter when the work calm down I will have more time and I do it and share it here. It will be a pin header that you can fit to the main pcb. It will have a current amplifier for switching IGBT or heavy duty fets, It can use ETD 39 for 500 to 700w and ETD 49 for 1000w or more. It is all being designed in my head for the moment but i will do it for real.

    Regards Silvio
    Waw ,, it sounds very nice ,, yes i will wait about that project ,, can it give power like an electric welding machine, ???

  6. #16
    .... Silvio's Avatar
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    Quote Originally Posted by Upik View Post
    Waw ,, it sounds very nice ,, yes i will wait about that project ,, can it give power like an electric welding machine, ???
    No it will not but it will give 1000w

  7. #17
    diysmps Senior Member
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    Quote Originally Posted by Silvio View Post
    Here is some software so that you can calculate your number of turns for the flyback

    PS if you really wanted to clone the smps then you should have dismantled the transformer and counted the number of turns. There also may be a gap in the center leg of the core.

    Regards Silvio
    Hi mr.silvio ,,, I am less so understand using this software..can you help me, ?? !!! that you post on page # 2
    Last edited by Upik; 05-22-2018 at 12:12 PM.

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