[amsat-bb] Mobile Computer / Radio Installations

Clint Bradford clintbrad4d at earthlink.net
Wed Apr 29 12:35:23 PDT 2009

 >> ... Most cigarette lighters circuits have a 15 to 20 amp fuse on   
them.  That ought to work fine for charging/using with your computer ...

That amount of current can/will destroy sensitive electronic devices.  
(20A??? That's more than what an Icom IC-706MKIIG uses at 100W TX  
power ... )

Personally, I would never run my laptop off a vehicle's charging  
system while the vehicle is running. You won't find many reputable  
laptop manufacturers recommending this.

And all power feeds to my radio gear are properly conditioned and  

If I needed to run my laptop for extended periods on a 12VDC system, I  
would use nothing less than a ...

Tripp Lite PVINT375
(although this model comes with a cigarette lighter plug, that  
connection has to be one of the electrically most UNreliable for what  
we are doing - so the plug gets whacked off and the unit is wired  
directly) ... or

Astron Pi-250W
12VDC-to-120VAC inverter made for such circumstances. Wire it in to  
your vehicle's 12VDC system, and simply use your existing AC power  
supply. Immediate benefit is the ability to power/ charge other  
electronic items you may have using regular AC chargers.

There's no need to know the voltage/current/connectors of the laptop.  
The laptop's manufacturer already did all that work for you when they  
supplied the AC adapter.

Another downfall of using the cig lighter circuit for comms: very  
rarely is that line filtered for noise and such. I mean, who needs  
that line filtered to heat up a cig lighter? More intelligent cars do  
have filtered/conditioned "power ports." But I do not leave anything  
to chance, and make sure my equipment is properly protected.

Then there are folks who run their 100W HF rigs through a cig lighter  
plug and swear that all's well with the world ...

And so it goes.

Clint Bradford, K6LCS

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