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Jeff Liebermann Jeff Liebermann is offline
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Default Analogue moving coil meter range extension?

On Fri, 22 Sep 2017 15:39:14 -0700 (PDT), wrote:

On Friday, 22 September 2017 05:22:46 UTC+1, Foxs Mercantile wrote:
On 9/21/2017 10:59 PM, tabbypurr wrote:
simple but time consuming producing a new dial paper


With the low current Zener, it doesn't look like that will be
necessary.


Oh, you've found a zener that's 10v +/- 1%?
NT


The meter isn't even that accurate. You're not going to be able to
read the meter to +/- 0.1V. Also, I coulnd't find where anyone
specified the accuracy required.

If you really want 1% accuracy, maybe a 10.0V precision reference,
such as the TI REF102:
http://www.ti.com/lit/ds/symlink/ref102.pdf
However, there's a problem. The IC requires a V+ of 11.4-36VDC which
will probably require a battery or other power supply.

Hmmm... I sorta blundered across this idea:
http://www.qsl.net/kh6grt/page4/expscale/expscale.htm
It doesn't expand the entire meter scale from 10-15VDC.
Instead, it compresses 0-10V into a small part of the meter scale, and
expands the 10-15V over the rest of the scale. However, it requires
+12v and -12v power.

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