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    12V to 220V with no isolation

    hello every one

    if my 12v to 220v converter using Boost topology and have no isolation .

    Click image for larger version. 

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    Whether this is contrary to standard?
    Not isolated, what problems may be the cause In a boost converter ?


    Thank you

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    Re: 12V to 220V with no isolation

    Non-isolated boost converters are quite common.

    If you don't need isolation you don't need isolation.

    But the problem is you have a high boost factor of about 20. This demands extreme duty cycle (~95%). Sometimes you turn to a transformer topology so the transformer can do the step-up for you (flyback for example).


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  3. #3
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    Re: 12V to 220V with no isolation

    For low current outputs, this is quite common.

    There are many "Nixie" power supplies which increase a low voltage source (usually 12 volts), to the Nixie's anode voltage, which is anywhere from 170 to 250 volts.
    And they use the exact same topology shown. Of course, current consumption is about a dozen milliamps or so.
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    Re: 12V to 220V with no isolation

    you need a "double" booster at least to go from 12V to 220VDC same gate drive to each cascaded stage ...


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    Re: 12V to 220V with no isolation

    Hi SS1_Raptor,

    Quote Originally Posted by SS1_Raptor View Post
    hello every one

    if my 12v to 220v converter using Boost topology and have no isolation .

    Click image for larger version. 

Name:	Boost-Converter-Topology.png 
Views:	1 
Size:	13.0 KB 
ID:	153858

    Whether this is contrary to standard?
    Not isolated, what problems may be the cause In a boost converter ?


    Thank you
    I would advise that dc-dc converters with output voltages in excess of 60Vdc should incorporate transformer for the sake of safety and regulatory obligations. Battery-operated appliances should have a voltage rating not exceeding 75Vdc which is the maximum.
    Last edited by Akanimo; 21st June 2019 at 06:37.
    -------------
    --Akanimo.


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    Re: 12V to 220V with no isolation

    I would advise that dc-dc converters with output voltages in excess of 60Vdc should incorporate transformer for the sake of safety and regulatory obligations. Battery-operated appliances should have a voltage rating not exceeding 75Vdc which is the maximum.
    This can't be a serious safety assessment without knowing any application details. Is the high voltage exposed to the outside, are there current limiting means? Isolation may or may not increase safety, depending on the connected circuit.


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    Re: 12V to 220V with no isolation

    Quote Originally Posted by FvM View Post
    This can't be a serious safety assessment without knowing any application details. Is the high voltage exposed to the outside, are there current limiting means? Isolation may or may not increase safety, depending on the connected circuit.
    Yes, it wasn't meant to be a complete safety recommendation. It was just based on the information provided by the OP.

    He can implement current limiting like you rightly said or even a limited power source by any known means if he wants.

    He would also give more information if he needs more help.
    Last edited by Akanimo; 22nd June 2019 at 12:39.
    -------------
    --Akanimo.


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  8. #8
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    Re: 12V to 220V with no isolation

    here is some stuff on the double boost as mentioned by EasyPeasy above


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