[sdiy] Knobs/scales

[Neil Johnson]

Merv, Paul, and all,

> the datasheet gives 270 deg as the 'electrical' rotation, 300 for the
> physical. Works for me although I dunno what the difference is.

What I believe this means is that although the shaft physically rotates
through 300 degrees, only 270 degrees of it actually has any effect on the
electrical behaviour -- the last 15 degrees of rotation at each end does
not change the electrical behaviour as the wiper is just skiding across
metal and not carbon.

The upshot of this is regarding panels is that the scale should be
arranged to span 270 degrees, but such that there is a 15 degree gap at
each end of the scale to allow for the extra mechanical rotation.

Hope this helps,
Neil

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Neil Johnson :: Computer Laboratory :: University of Cambridge ::
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