[Mobile-Portable] Re: Laptops Near Mobile Rigs

[doc]

 > Hsu, Aaron (NBC Universal) wrote:
> One option is to run the laptop directly off a battery or the cig
> lighter / accessory socket.  Make sure the supply leads to the laptop is
> well filtered to prevent the trash from the car's electrical system from
> damaging the laptop!  You'll be limited to the 13-14 volts the car
> provides - this is generally enough to run the laptop, but it probably
> won't allow the laptop to charge the laptop's battery unless your laptop
> only requires 12v to start with.  If you have one of the "high-current"
> 12v cig lighter adapters, check to make sure it isn't a switching
> adapter as this will also cause noise.  Just "wire your own" using a
> fuse and some choke circuitry.  Also, don't use an DC-AC inverter as
> these are switchers and will also generate quite a bit of hash.

I have observed that laptops designed for 19VDC
will not operate some accessories, e.g. network
cards, if the voltage is too low.

I am guessing that the system "sees" low voltage
as a sign of the battery discharging and lowers
demand accordingly.

There has also been a concern expressed that
low voltage = higher current and
higher current = more heat on tiny traces and
in sensitive tiny components thus raising the
probability of early failure.

Also, I am told that some of the laptop batteries
are not even 12vdc so a high enough charging voltage
should not be an issue but that tells me that there
could be a dc-dc converter in the laptop that is
engaged when the battery is used for power.

To keep things simple I am looking for a 12vdc
(12-15vdc) native laptop.

I will sell my three IBM Thinkpad 600-series
laptops once I find a 12vdc native replacement.


-- 
Thanks! & 73, doc kd4e  http://bibleseven.com
Ham Links: http://bibleseven.com/hl.html