what's the deal with solar calculators?

[megarat]

Hey all,

Since I was a kid (say, 20 years ago), I've always had a big warm heart for solar calculators. A piece of electronics with an integrated ability to run self-sustainably just seemed like a beautiful thing. And in a sense, I've always seen it as a shame that HP never created any (good) solar calculators.

(Please note that I'm an RPN nut and an evangelist of HP calcs ... I own several Voyagers plus an HP 48sx, and I think the 15c is the most remarkable calculating device ever created. It's just unfortunate that it's not solar-powered. You might argue, "With a US$10 set of batteries that runs for twenty years, why would you need solar?" and to that I'd respond, "That's not the point.")

So other companies are creating some super solar scientific calcs ... TI, Casio, Sharp (especially the Sharp EL-506WBBK ... that's a serious bang for the buck), but HP's only solar attempts that I've seen are very basic (and half-hearted) calculators. I suspect the HP-49/50-level calcs (like the TI89) need more juice than a tiny photovoltaic can offer, but why not the 33s? Or even the 9s/30s?

Does anyone know why HP has stayed away from solar? (And by solar, I include "dual-power" (with a battery), to maintain continuous memory.)

[Marcus von Cube, Germany]

Somehow, memory contents must be preserved for any no-nonsense scientific calculator. So you need batteries anyway.

Marcus

[Walter B]

Hi Marcus, that wasn't the point, see above. IMO the customer wants to feel ecologically correct while using a calculator. So anything looking like a solar cell on top of the calc would do it, be it connected to the electronics or not d;-)

[Bern]

He did state that batteries are also needed.

I just wonder how much a solar cell would help with a power hog like the 50g. Mine uses a set of batteries every three weeks.

There is also a space issue. Does the calculator then have to be larger of will the solar cell take away from the display area?

[Karl Schneider]

Quote:

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I own several Voyagers plus an HP 48sx, and I think the 15c is the most remarkable calculating device ever created. It's just unfortunate that it's not solar-powered.

...

I suspect the HP-49/50-level calcs (like the TI89) need more juice than a tiny photovoltaic can offer,...

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I have yet to see a powerful calculator (i.e., one that performs computationally-intensive functions such as integration, graphing, and calculations with large matrices) that is solar-powered. Their processors draw significant power to run these functions quickly. Every solar calc I have -- even the new ones -- are rather slow.

Also, a solar panel will lengthen the calculator. A larger HP-15C that ran its functions of solve, integrate, complex-number math, and matrix operations even slower than it already did, would be rather unappealing.

-- KS