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A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

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Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#31

Post by a1369209993 »

hetman wrote: post #29
a1369209993 wrote: post #26

Earlier quoted context omitted.

I assume the obvious solution of just running power conversion at GHz frequencies would waste too much power as EM radiation, correct?

At those frequencies you're going to be losing a lot of power in the switching losses of the transistors. Power MOSFETS have very low leakage when fully on or off, the largest loss tends to be during the transition when voltage and current are non zero. Because the speed of that transition is limited, the higher the frequency the more percentage of total time is spent in those transition phases and the higher the los…

Yeah, that makes more sense than radio emissions, thanks.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#32

Post by mrfusion »

jmwilson wrote: post #27
tgflynn wrote: post #21

Earlier quoted context omitted.

> If you want to miniaturize electronics you need to miniaturize the inductors used in power conversion Hasn't that problem mostly been solved already with switch mode power supplies that are pretty small. With most personal electronics being battery powered these days I'm curious where you see a real need for further reduction in the size of power converters. In other words what technologies or devices are currently…

> Hasn't that problem mostly been solved already with switch mode power supplies that are pretty small. Perhaps you are thinking of "wall wart" power supplies that used line-frequency transformers in their rectifier design. These have been replaced and miniaturized by using offline switched-mode power supplies and point-of-load converters, but the magnetic components remain the largest components in these designs. >…

So wall warts are obsolete? What breakthroughs replaced them?

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#33

Post by mlyle »

tgflynn wrote: post #30
as-j wrote: post #25

Earlier quoted context omitted.

> Hasn't that problem mostly been solved already with switch mode power supplies that are pretty small. I waste a ton of board space with power supplies. Not everything is personal electronics with custom ICs* in the volume of an iPhone. So this means on my current design there's power supplies for 1v, 1v8, 2v5, 3v3, ~4v, 5v. Each of these the biggest component is the inductor. I've sometimes joked, I make power supp…

Are all of those drawing significant current though ? If you just have some small component with an odd voltage requirement that doesn't need much current couldn't you supply it with something a lot simpler than a dc-dc converter, like maybe a voltage divider or linear regulator ?

Almost certainly not a voltage divider. Maybe a linear, if efficiency doesn't matter.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#34

Post by coryrc »

mrfusion wrote: post #32
jmwilson wrote: post #27

Earlier quoted context omitted.

> Hasn't that problem mostly been solved already with switch mode power supplies that are pretty small. Perhaps you are thinking of "wall wart" power supplies that used line-frequency transformers in their rectifier design. These have been replaced and miniaturized by using offline switched-mode power supplies and point-of-load converters, but the magnetic components remain the largest components in these designs. >…

So wall warts are obsolete? What breakthroughs replaced them?

The cost of switching power supplies. (your USB charger the size of a plug puts out more power than a transformer wall wart 6x8x8 cm)

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#35

Post by topspin »

andrewjrhill wrote: post #5
tyingq wrote: post #4

It mentions 50 percent greater inductance than a a regular coil. Which is great, but would only reduce the size by a third. I imagine this has some use cases that would merit the higher cost (graphene is expensive, right?). But probably not many.

To be fair - a 33% reduction in size is massive for something that has remained largely unchanged for the better part of 2 centuries.

20-30 years really. The introduction of chip inductors, the last really significant reduction in size for commodity discrete inductors, happened in the 90s.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#36

Post by coryrc »

rini17 wrote: post #13
wbraun wrote: post #9

Earlier quoted context omitted.

Its a material that basically gives electrons "inertia" which acts like an inductance derived from magnetic fields. There is a time constant to it, which determines at what frequency range it starts contributing to the inductance value. To make it useful for power electronics they would have to push out this time constant by at least 4 orders of magnitude, I don't believe the theoretical material properties support t…

Perhaps power electronics will move to higher frequencies, too.

Will have to drive gate and source capacitance down a few orders a magnitude to make that a reasonable trade-off.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#37

Post by ncmncm »

This will be a bigger deal when they get better effective carrier mass. It reads like intercalating more boron, or maybe a better choice or mix of elements, will yield increasingly better results. 50% is a big enough initial effect to be very encouraging. It is not clear from the article if there is any theoretical upper limit.

In the meantime, making the biggest part of a circuit 33% smaller might make the whole circuit almost that much smaller.

The value of these things is greatest manipulating signals at very high frequencies, far out of reach of digital signal processing. It is probably not notably useful for power conversion, where the exchange of energy via actual magnetic fields is what does the useful work.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#38

Post by topspin »

im3w1l wrote: post #16
myself248 wrote: post #14

Earlier quoted context omitted.

At the frequencies relevant to the present invention, mostly RF front-ends. Wireless cards, cellphones, radars, etc.

And it will make the devices smaller? Cheaper? Higher performance?

Some of all. Inductors are particularly difficult to accommodate in contemporary circuits, so a general reduction in size could have an outsized impact.

Re: A 189 Year Old Limitation on Inductor Size Has Been Broken (2018)

#40

Post by dogber1 »

So many hyperbolic claims that boil down to a moderate 33% area benefit with very little data about mundane things like long-term reliability, or process variation.

Every time an article mentions some buzzword like 'graphene', it turns out to be just a load of baloney. Graphene can do everything but leave the lab.

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