Wireless at Osh

Probably true, but this is a week long camping trip, with
the battery being used as the power source for an inverter
to use the 110 VAC to charge the laptop. It would be best
to get a cigarette lighter adapter for the cellphone and
skip the step of the inverter.

If you fly-in, just go to a nearby store and buy a cheap car
battery and after the event, donate it to the shop for the
airport beater or tractor.



"Vaughn Simon" wrote in
message
...
|
| "Jim Macklin" wrote
in message
| news:JTxng.49575$ZW3.40014@dukeread04...
| Most small solar panels have low amperage and will not
over
| charge a wet cell battery. If they were used to
directly
| charge a dry cell battery, such as a C or D cell they
might
| over charge, but a wet cell battery with an AHr rating
of 25
| amps can be charged indefinitely at a rate of 2-3 amps
and
| you will be using the battery to run an inverter to
power
| various other loads.
|
| This may be true for a few days of operation at a
campsite, but overcharging
| is overcharging, and it will eventually trash your
battery. Take it from a guy
| who ruined far too many batteries with cheap one-amp
trickle chargers before he
| learned. In general, solar panels need charge controllers
for long-term
| successful operation.
|
| Vaughn
|
|

There are constant voltage chargers and there are also
constant current chargers. The solar panel is a constant
voltage charger and is thus self-limiting. It is rated at
750 milliamps at 14 volts, so it will not over charge a
lead-acid battery that is also being used on a daily basis
to charge laptops, cellphones and other small devices,
perhaps with the use of a solid state inverter.
A generator is the nicest thing, but unless they are flying
a Cessna Caravan or a King Air, the weight of the generator
might be better used for extra shoes, socks and sun
protection. A cheap lead-acid battery can be purchased when
they arrive at OSH and given away when they leave.

Carriage of a lead-acid battery in the aircraft is
considered hazardous material, it can easily damage the
aircraft structure by concentrate weight or acid spills.
Carrying a generator is also a problem once it has had fuel
in the tank.

Let's take a vote, is Matt an a-hole or am I an idiot?


Matt, I don't think you actually read what I wrote, I
mentioned both lead-acid (wet cell) and dry cell batteries.
The OP was talking about a dynamic system that would be in
nearly full time use keeping their portable electronic world
alive. I actually think that the 3/4 amp solar cell would
be hard pressed to keep the charge up in a lead-acid
battery. In any case they would need to charge the battery
during the day and use the charged battery over-night to
charge their devices.


--
James H. Macklin
ATP,CFI,A&P

"Matt Whiting" wrote in message
...
| Jim Macklin wrote:
|
| Most small solar panels have low amperage and will not
over
| charge a wet cell battery. If they were used to
directly
| charge a dry cell battery, such as a C or D cell they
might
| over charge, but a wet cell battery with an AHr rating
of 25
| amps can be charged indefinitely at a rate of 2-3 amps
and
| you will be using the battery to run an inverter to
power
| various other loads.
|
| Your understanding of electricity is only exceeded by your
understanding
| of stall dynamics. It would take in increasing voltage to
maintain 2
| amps into a wet cell battery as it becomes charged. If
you maintain
| that rate for more than 12-13 hours, you will soon ruin
the battery.
| The good news is that most chargers (and certainly a PV
cell) maintain a
| roughly constant voltage so that the amperage tapers off
as the battery
| approaches full charge.
|
|
| Matt

BTW, Matt, I did not say that the solar panel would charge 2
amps, what I said was that a lead-acid battery can take a
constant 2 amps (10%) of the amp/hour rate as a limitation
of the battery.



"Matt Whiting" wrote in message
...
| Jim Macklin wrote:
|
| Most small solar panels have low amperage and will not
over
| charge a wet cell battery. If they were used to
directly
| charge a dry cell battery, such as a C or D cell they
might
| over charge, but a wet cell battery with an AHr rating
of 25
| amps can be charged indefinitely at a rate of 2-3 amps
and
| you will be using the battery to run an inverter to
power
| various other loads.
|
| Your understanding of electricity is only exceeded by your
understanding
| of stall dynamics. It would take in increasing voltage to
maintain 2
| amps into a wet cell battery as it becomes charged. If
you maintain
| that rate for more than 12-13 hours, you will soon ruin
the battery.
| The good news is that most chargers (and certainly a PV
cell) maintain a
| roughly constant voltage so that the amperage tapers off
as the battery
| approaches full charge.
|
|
| Matt

meant to say 750 milliamps (3/4 of an amp).


"Jim Macklin" wrote
in message news:h9Cng.49592$ZW3.38038@dukeread04...
|I looked up the item after I sent it out, the specs say 750
| milliwatt and 14 volts. It is a good trickle charger, as
| long as you don't put too much load on the battery. It
| should do fine for charging cellphones, cameras, and even
| the laptop. But if they are all on the inverter at one
time,
| the battery will be discharged.
|
|
|
| "Larry Dighera" wrote in message
| ...
|| On Sun, 25 Jun 2006 09:51:51 -0500, "Jim Macklin"
|| wrote in
|| JTxng.49575$ZW3.40014@dukeread04::
||
|| Most small solar panels have low amperage and will not
| over
|| charge a wet cell battery.
||
|| The solar panel mentioned has a 13 watt rating. That's a
| little over
|| 1 amp at 12 volts (in full sun).
||
|
|

"David Dyer-Bennet" wrote in message
...
john smith writes:

In article ,
"Brian O" wrote:

"john smith" wrote in message

...
In article , John T
wrote:

This has been a recurring topic with no clear answers.

I say, hoof it over to the hilton. They have wireless for their
guests.
There is no sign on page, but I have no idea what their range is.

And someone will be sitting there with their laptop watching
everything
streaming by in the ether. Google "ethereal" for more information.
:-))
Beware of ARP cache poisoning, also.
Never use any program which transmits any of your passwords over an
open
wireless network.

Why would you not want to use any programs that transmits any
passwords?
They are just as encrypted as they would be over a landline or dsl
connection.

Unless you are logging into a private VPN service through the open wifi
connection they are not. Beware of the man-in-the-middle!

Well, https is encrypted, for web stuff. Mostly, though, I connect
back to important places via SSH, which is very carefully encrypted.
If you've connected from that laptop to that destination before, SSH
also remembers the host key info, and can then detect
man-in-the-middle attacks, as can https.
--
David Dyer-Bennet, , http://www.dd-b.net/dd-b/
RKBA: http://www.dd-b.net/carry/
Pics: http://dd-b.lighthunters.net/
http://www.dd-b.net/dd-b/SnapshotAlbum/
Dragaera/Steven Brust: http://dragaera.info/

What is SSH? I guess Im right about the https being encrypted. I doubt you
would have any problems as long as you are using web stuff.
B

Tom McQuinn wrote:

Newps wrote:

Try this. I bought one last year from this guy. Works great.


http://cgi.ebay.com/Brand-New-12V-Br...QQcmdZViewItem




Can you just hook this up directly to maybe a sealed lead acid battery
or a gel cell and charge it?

Yes, it comes with male and female cig lighter plugs as well as
alligator clips to hook right to the battery.

"Brian O" wrote in message
...
What is SSH?

A simplistic description would be that it's telnet with security.

I guess Im right about the https being encrypted.

By definition, https is encrypted. But then, I didn't see you make any
statement like "https is encrypted". How are you right?

I doubt you
would have any problems as long as you are using web stuff.

It just depends. Many users don't have a clue whether they are using an
encrypted link or not (http vs https). Any web site dealing in sensitive
information *should* be using https, but the user should confirm that and
I'll bet the majority don't even know *how* to confirm it, never mind do
they do so.

Also, not all POP, SMTP, or NNTP servers require encrypted passwords and
many users may not be using encrypted passwords. Heck, as far as I can
recall, the DUAT web sites don't use https.

As far as your original statement that "They are just as encrypted as they
would be over a landline or dsl connection", I suppose that's true depending
on your definition of "encrypted". Technically, with respect to the actual
data being transmitted over the Internet, you're right. But the very nature
of a wireless network makes it less secure. It is relatively safer to
transmit unencrypted data over a hard-wired network connection than it is to
do so over a wireless connection, because it's more difficult to extract the
data being sent over a hard-wired network connection than it is to do so
over a wireless connection (especially a public one that is likely not using
any encryption such as WEP or WPA).

Of course, that said, I think it's a good idea for anyone to treat *any*
public or quasi-public network connection as unsecured and equivalent to
wireless whether wireless or not. Not that one's home DSL connection is
guaranteed to be secure either, but the likelihood of someone intercepting a
private line like that is fairly remote, especially compared to the
likelihood of a public service provided by a third party being compromised.

And of course, *that* said, there's probably not much reason for a user to
not be avoiding plain-text passwords and sensitive data regardless of their
network connection. So the advice to not use such things on a wireless
network is perfectly valid, but probably ought to be applied across the
board and not just while at OSH.

Pete

In a previous article, "Peter Duniho" said:
And of course, *that* said, there's probably not much reason for a user to
not be avoiding plain-text passwords and sensitive data regardless of their
network connection. So the advice to not use such things on a wireless
network is perfectly valid, but probably ought to be applied across the
board and not just while at OSH.

If you are on a public wireless network with your own laptop, you should
make damn sure that any site you care about your passwords for (email,
banking, etc) are using ssl to connect (https is http over ssl).

You should also assume that any public access computer, wired or wireless,
is infested with keyboard sniffer programs and hardware and any password
you use on those systems will be immediately captured and sent to people
who will use them for neferious deeds. Never read your email or visit a
banking site at a public access computer (especially not in "internet
cafes"). Even if they wipe the software and reinstall it after every user
(and most places dont), a person could install one of these:
http://www.thinkgeek.com/gadgets/electronic/5a05/ or
http://www.thinkgeek.com/gadgets/security/7af2/
and capture every keystroke on the computer without anybody knowing.

--
Paul Tomblin http://xcski.com/blogs/pt/
Died. Woke up in Hell. Punched in PIN, logged on. Just another day.
-- David Gerard

"Jim Macklin" wrote in message news:lZdng.49541$ZW3.43705@dukeread04...
You can get a solar panel to keep the aircraft battery
charged and a solid state inverter should work fine to run
your cellphone and laptop chargers.


Any recommendations for solar panels?

My popup campers battery lasts most of the nearly week and half I'm at
osh. Mostly charging the cell phone, my implant batteries, and lights at
night for reading. I have a yamaha 1000watt generator for charging the
battery (I use a regular charger, not the wimpy "built in" charger in
the generator).

I don't use the battery for anything else. I don't bring a computer
cause of no network, and there isn't much to watch on a 9" TV unless its
really good and on VHS tape.

John