I skimmed it. I'd agree pretty much with Dave. It looked pretty
superficial to me and getting 60V out of a 1/4 wave antennae at mW
power levels just doesn't seem right for an untuned system even using
a charge pump.

As for using a "monopole" antennae coiled around "because it doesn't
need a ground plane",  - it just doesn't look feasible.

I do wonder how much 60Hz or monitor radiation it was picking up in
addition to the 915MHz signal but even so he claims to have got 100V
out at one stage - without stating the input level. I wouldn't have
thought the diodes he was using would handle anything near that.

RP

On 15/06/07, microbrix@gmail.com <microbrix@gmail.com> wrote:
>  Anyone read the article?
>
>
> On 6/14/07, piclist@mmendes.com <piclist@mmendes.com> wrote:
> > >> Gentlemen..  If you're so disposed, and in need of some comic relief,
> > >> I'd appreciate your thoughts on the following article.  I couldn't get
> > >> a reasonable URL for it, but if you google the following, it's the
> > >> first hit.
> > >>
> > >> "Daniel Harrist - Wireless Battery Charging Systems using Radio
> > >> Frequency Energy Harvesting"
> > >>
> > >>
> > >> Am I nuts, or is this really as badly done as I think it is?
> > >>
> > >> I notice in his simulations that the RF source is not spelled out to
> > >> us, wether it is a mW or a MW will have some impact on the results.
> > >>
> > >> Also, I am somewhat (gag-cough-sputter) skeptical of how much power is
> > >> available within the volume of space captured by a 915 MHz whip
> > >> antenna.  He also seems to want to improve this by using a smaller
> > >> antenna!
> > >>
> > >> Finally, the load in sim is simply a capacitor, so his sim reflects NO
> > >> ability to deliver joules into a battery.
> > >>
> > >> Frankly, I don't see this working unless it's used INSIDE a microwave
> > oven.
> > >
> > > Well now that you mention it... I've sure you've all seen those little
> > > heat pack things that you put in the microwave to warm up.
> > >
> > > Why not a flashlight that you put in the microwave to charge?
> >
> > Because whenever I remember that I should've charged the flashlight
> > there is no
> > power to use the microwave?.... ;)
> >
> > -Mario
> >
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