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  1. #1
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    Core losses in the inductor

    Hello everyone

    We use steinmetz equation to find the corelosses. I have four coils from different suppliers and I want to know core losses in each coil. Problem is that there is no information in the data sheet about the core materials and no flux density, frequency and power graphs are given as the suppliers do not want to share this information and keeps this as secret secret. Without this information I cannot use steinmetz equation. The dimensions of the inductor, inductor and temperature rise vs current graphs are given.

    How can I find the corelosses in this situation, Is there any other alternative way?

    Regards
    Ghufran

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  2. #2
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    Re: Core losses in the inductor

    Generally, you need to measure the losses versus frequency and flux empirically. That's also what manufacturers do. Steinmetzt equation isn't but a simplified estimation of actual behavior.



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  3. #3
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    Re: Core losses in the inductor

    I presume you mean ferrite inductors....some maunfacturers like vishay, coilcraft, Wuerth, give software to allow you to calculate core loss in whichever inductor.
    But otherwise, you just have to make do with thermal measurements with thermocouples glued to the ferrite.



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    Re: Core losses in the inductor

    Quote Originally Posted by treez View Post
    I presume you mean ferrite inductors....some maunfacturers like vishay, coilcraft, Wuerth, give software to allow you to calculate core loss in whichever inductor.
    But otherwise, you just have to make do with thermal measurements with thermocouples glued to the ferrite.
    That will give you temp rise, but then you'd also need
    to measure the heat-throw vs temp somehow. Maybe
    just baseline a DC power vs temp-rise cal-curve? What's
    the done thing, there?


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    Re: Core losses in the inductor

    really you are interested in the overall losses - make a buck ckt at the design frequency and with the design current, with a fixed Vin and load - then put in the differing chokes - one at a time - and measure the Trise with time - this will show the lossiest snd the least lossy ...



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    Re: Core losses in the inductor

    forgive my ignorance, but in the Physics class, we did draw the B-H curve and we had a box connected to a CRO that can display the hysteresis graph. It should not be difficult to set up a similar experiment.



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  7. #7
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    Re: Core losses in the inductor

    we had a box
    The box contains a current sense amplifier and an analog integrator to convert voltage to flux. Modern digital oscilloscopes can often do the signal integration without additional hardware.



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