But he needs Vout to go both above and below Vin.
an.2005.05.01.20.58.47.35645@example.net...On Sat, 30 Apr 2005 20:16:34 +0000, Colin Dawson wrote:
"Rich Grise" <richgrise@example.net> wrote in message
What exactly does "works best" mean? What does this telescope actually
do that cares whether the voltage is at the low or high end of the spec?
...perfectly, then as the night wears on, and the voltage on the battery
drops the tracking will get gradually less accurate.
Then, since you've asked in an electronics NG, the answer is to repair
your timing mechanism. Or redesign it. You _could_ use a "low-dropout"
regulator, but then you're still dependent on the accuracy of your
voltage regulator. I once saw a thing on teevee where they had an
actual, mechanical, clock movement to track their scopes. BIG scopes. I
saw the balance wheel going "tick tock, tick tock, etc." In other
words, you're asking the wrong question. There are folks here who could
design a scope tracker for you that would beat _anything_ that you could
come up with by just trying to regulate the input voltage.
Heck, use a clock! And a crystal-controlled reference. Practically
nothing to it, and it could run from, say, an eight to, say, eighteen volt
power supply, with probably better than 0.001 percent accuracy! Really!
Just ask Jim Thompson! ;-)
Oh, wait a minute - he's the analog guru here
much easier!
60?)
Good Luck!
Rich
(.001 percent is 100 ppm, right?)
Colin Dawson <newsgroups@cjdawson.com> wrote:
Juptier, easy, it's the brightest star in the sky[...]
...and I had always thought Jupiter was a planet.
Ah well, shows how little I know about astronomy.
--
~ Adrian Tuddenham ~
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