On Fri, 1 Mar 2002, ZN wrote:
> Why? A contact resistance of anything up to... <snip>
It's the physical characteristics I need to measure, not the layout.
> The bubbles are about 13mm in diameter and the spacing is, IIRC 0.27mm...
> those neurons are about to be reused so don't hold me accountable if I'm
> wrong. Several of the bubbles in a single row are connected together by
> virtue of narrow cutouts on the spacer - 5 or 6, usually. This reduces
> pressure buildup in the bubble, when it's pressed into.
> Samsung membranes were separable, had no connections between the 'bubbles',
> were made of clear material, and had thick silver lines you could even
> solder to with some attention, and the contact points had small graphite
> circles printed on them.
> Very erly sinclair membranes were very similar to the Samsung ones, just
> not separable and without the graphite pads.
> The largest majority of Sinclar membranes were glued together (with a glue
> that chemically interacted with the signal lines...), were made of milky
> white material that resembles drafting transparency, had very thin
> silver-on-thallium plating that would easily corrode (soldering is
> completely out of the question here), and would eventually go brittle with
> heat and crack. Essentially the same as with the Spectrum.
That's better :o)
Ok, now all I need is a draft sheet of the exact physical positioning, and
the location and dimensions of every slot, cutout, locating notch, etc ;)
Thanks for the construction info - it's useful, and will be used. Thanks
:o)
Dave
ql.spodmail.com
