On Friday, 22 September 2017 04:26:17 UTC+1, Foxs Mercantile wrote:
On 9/21/2017 6:35 PM, T i m wrote:
But still, ohms law applies and with just a series resistor to limit
the current for FSD, zero on the meter (re-marked to display 10V)
won't reflect the required 10V.

Now, ya see, I missed that.
you want a 10-15 volt meter, not a 0-15 volt meter.

The simplest is a 20K resistor in series with a 10v zener diode.
Use a low current Zener so the knee works right at low values.
Something like this:
http://www.mouser.com/ds/2/395/BZX55C2V0%20SERIES_D1610-1099630.pdf

Depending on how non-linear the low end is, you can print a custom
dial scale that has been corrected for "this voltage is this mark."
http://www.tonnesoftware.com/meter.html
Although this one looks to be linear down to 10 uA or better.
10 uA would be approximately 0.2 volts above the Zener voltage.
or 10.2 volts on a 10-15 volt scale.

simple but time consuming producing a new dial paper


NT