On Sunday 08 February 2009 07:17:32 pm Ethan Dicks wrote:
On Sat, Feb 7, 2009 at 5:38 PM, Allison <ajp166 at
bellatlantic.net> wrote:
> On
Thu, 5 Feb 2009, Allison wrote:
> > The only reason batteries are needed to run the NLS is the charger is
> > way too small run run it directly.
For the NLS 'scopes the battery is between the charge source and the
scope power supply so if it's open (badly sulfated as the battery is
lead acid gell type) the PS has to carry the load. It's only a charger.
if you substitute a larger charger then you find the charge circuit
does not have the capacity to start the unit (initial surge current).
That all sounds consistent with observed behavior.
In this case (nls miniscopes) a 6V PS can
substitute for the battery at
less tha 1A (must be connected to the ground and +6V termianls of the
battery connection point internally). Only if the battery is removed
first. Note that is the battery has failed (usually sulfated from not
being kept charged) they tend to build corrosion around the terminal,
they are best removed and recycled as any gelled lead acid battery should
be.
OK. I may try that. I can probably use a bench-top supply, and now
that I know the batteries are not made from unobtanium, I'll probably
just remove them and drop them off at a Batteries Plus or wherever one
disposes of non-alkaline batteries these days.
I'd think that probably any place that handles lead-acid batteries should be
able to take them off your hands. I'll probably be doing something similar
with the gels I end up with in the UPSs I have to poke through here. I'd
also figure that any place doing a fair amount of business in car batteries
shouldn't object to adding some gels to the pile.
Since I use my
miniscopes intermittently I've long since removed the
battery and disconnected the internal charge circuit (pull the fuse).
The battery area has a small board inserted to allow it to accept any
voltage from 9 to 30V and run from that. Since I have a number of small
12V gell cells that fit nicely in the probe pocket of the carry case
this proves more useful and maintainable. The change is completely
reverseable and the ability to use a larger and longer lasting 12V
battery as source is very handy.
Interesting. I have the schematics somewhere (I found them on the
'net after not too much searching), so I may give that a try
How much do those amount to in terms of bulk? I might be interested in taking
a look if it's not too much.
The NLS is
somewhat unique as it uses a lead acid type rather than NiCd,
Nimh, lithium or even common dry cells. In an emergency I have run it
off 4 'D" sized alkaline cells in an external holder for many hours.
Also an interesting suggestion.
I will probably try some temporary method of powering this up first -
it came to me in an inert state, so I can't be sure the device doesn't
require repair first.
Thanks for the all the good tips, Allison,
-ethan
I'm pleasantly surprised on this list with fair regularity. :-) That having
been the case with these scopes, I'm beginning to wonder, how easy is it to
find one these days, and what might it take to get my hands on one?
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin