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Tugdual · 02-10-2014, 04:20 PM

(02-10-2014 11:52 AM)robert rozee Wrote:
(02-10-2014 07:55 AM)Thomas Radtke Wrote: According to their initial webpages, a fullsize clone was their original idea until the plans for a 15C LE were unveiled. It was a very unlucky coincidence.
and yet the 15C LE is a rather poor product as a 'collectable'. the software issues are quite minor when compared to mechanical and materials considerations. it is very unlikely that even a fraction of the 15C LE calculators made will still be functional in 10 years time due to failure of the flexible conductive plastic cable between PCB and LCD, and also because of the use of lead-free solder in the construction. there will be no one who buys a 15C LE at the beginning of their career and still has the same calculator operating at the end.

the materials in the cable decompose over time, leading to the ends detaching. while lead-free solder grows dendrils (long tin crystals), which eventually produce shorts between adjacent pads. these are both well known issues in the electronics industry.

a swiss-micro effort could, on the other hand, produce a 15C clone that would have a lifespan approaching that of the original 15C, however it would require careful selection of materials and components. a good design would allow for replacement of parts that failed.

rob :-)

I kept (and still own) my original HP 15C for more than 20 years. I must have changed the batteries 2 or 3 times... and apart from a missing rubber pad it still looks good. But there is an issue with it: it looks like the rubber pad below the keys hardened to the point that I really have to heavily press the keys and sometime miss some strokes. This is the reason why I purchased the LE, this plus the amazing speed which brings comfort as you enter calculations: the screen doesn't blink or respond slowly like if the crystal was cold this makes a huge difference.
I’m a bit sad to read that you predict a soon failure of my LE. I just hope I’ll be able to repair it if this was to happen. A good calculator is a tool you have in your pocket (reasonably small and light), with keys (not a smartphone) by nature quick easy to use. I don’t think the Swiss design can compete with the LE keyboard reason why I would still prefer the first.