21 Apr
1998
21 Apr
'98
9:33 p.m.
<> =============================================================guide rai
<> +
<> +
<> +
<> +
<> +++++++++++++++++++++++++++ <<<<<<<direction of motion (96
needed)
<> ^ +
<> | +
<> / +
<> | +
<> |=============================================================guide rai
<> ^optos to read the leading edge of the card for column clock, spacing
<> is such that each one is obscured as the column is over the column
<> leds making it self indexing. It's possible to go very fast.
<
<Now that I like!. I wonder where I can find some cheap photodiodes.
<
<What about one of the CCD (or similar) linear image sensor chips? They're
<quite cheap in surplus shops now, I think... A bit of optics to focus the
<image onto the sensor, and a bit of electronics to drive it (which is not
<that hard to design).
CCD needs a fair amount of electronics, photo transistors are cheaper and
simpler. Jade, JAMCO, JDR and BG micro list phototransistors pretty
cheap.
Allison