On Tue, 12 Feb 2002 09:32:54 +0000 David Kirkby <drkirkby@ntlworld.com>
writes:
Hi everyone,
Sorry for the tardy comment but, this reply got stuck in e-mail limbo.
> Kenneth D. Grimm, K4XL wrote:
>
> >>I have the 43P kit, and it does indeed work about as you indicate.
> > Use an external power supply for it, though, the thing goes through
9v
> > batteries
> >>(two at a time!) like water through a sieve.
> That sounds like very poor design. The meter is only 30 uA, so even
> to keep the meter at FSD, cells should last almost forever. The
electronics to keep
> the peak must use very little power - a precision rectifier and storage
capacitor
> would probably do it. Something seems amis.
> --
> Dr. David Kirkby PhD,
Methinks the trouble is that the peak conversions I've seen use
standard op-amps with a couple MA of power supply current.
I built one of those myself, in the last millennium, using a National
LMC6462, micropower CMOS dual op-amp. It runs on 3V (single supply) and
consumes only 12uA in standby. It will run a long time (2000 hrs.?) on
a Lithium coin cell or years on a pair of AA cells.
73 & Good afternoon,
Marv WC6W
*
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.
|