Have you tried replacing R2 with a diode 1N914 etc? This will cancel
the Vbe voltage of the transistor and should give you a bit more range
and temperature stability.

RP

On 18 July 2012 21:17, IVP <joecolquitt@clear.net.nz> wrote:
>> I have attached a slightly improved circuit with wider adjustment range
>
> Thanks, I've been playing around with R either side of pot, as well as
> varying both the 5V and the 10V. I'll also try it on a few PIC types to
> see if there's any great variation
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.