... 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 filtered.
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 http://www.clintbradford.com 909-241-7666
This is definitely one of the areas I need to investigate further in light of multiple requests to expand my original post and submit it to the Journal for possible publication.
There are a couple of other areas I need to do more work on, too. -------------- Original message from Clint Bradford clintbrad4d@earthlink.net: --------------
... 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 filtered.
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 http://www.clintbradford.com 909-241-7666 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I did some research into this many moons ago and compiled a good amount of information.
Clint Bradford wrote:
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.
I know for a fact that Dell, HP, and Acer all make car chargers. I consider them fairly reputable. :)
What kills laptops are adapters that don't "insulate" (for lack of a better word) the initial spike when you start your car. That can be fairly crazy on voltages and if the adapter passes that through, it can be fatal to computer equipment.
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.
While, yes, these will work, this is the most inefficient way of charging your laptop. Essentially you're getting AC from the alternator, converting it to DC for the car, converting it back to AC via the inverter, only to convert it back to DC to charge your laptop. Not good..
Ben,
You will find many military power supplies that do the inverse, convert DC to AC back to DC...my 50 KVA UPS units at work convert AC to DC to AC....
If your engine is already running and already producing DC, I think the lack of efficiency is of very little consequence....especially if you're looking at the 90 watts or less that is required to run a fairly powerful laptop.
Many people drive with their lights on during the day, I'd say that is less efficient than charging/running your laptop from an AC inverter.
73 de Tim, K4SHF
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Ben Jackson Sent: Thursday, April 30, 2009 10:28 AM To: Clint Bradford Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: Mobile Computer / Radio Installations
I did some research into this many moons ago and compiled a good amount of information.
Clint Bradford wrote:
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.
I know for a fact that Dell, HP, and Acer all make car chargers. I consider them fairly reputable. :)
What kills laptops are adapters that don't "insulate" (for lack of a better word) the initial spike when you start your car. That can be fairly crazy on voltages and if the adapter passes that through, it can be fatal to computer equipment.
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.
While, yes, these will work, this is the most inefficient way of charging your laptop. Essentially you're getting AC from the alternator, converting it to DC for the car, converting it back to AC via the inverter, only to convert it back to DC to charge your laptop. Not good..
-- Ben Jackson - N1WBV - New Bedford, MA bbj <at> innismir.net - http://www.innismir.net/ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Especially as many vehicles have the inverter built in by the manufacturer.
Tim Tapio wrote:
Ben,
You will find many military power supplies that do the inverse, convert DC to AC back to DC...my 50 KVA UPS units at work convert AC to DC to AC....
If your engine is already running and already producing DC, I think the lack of efficiency is of very little consequence....especially if you're looking at the 90 watts or less that is required to run a fairly powerful laptop.
Many people drive with their lights on during the day, I'd say that is less efficient than charging/running your laptop from an AC inverter.
73 de Tim, K4SHF
Lenovo also makes Laptop power supplies that are designed to be powered from a nominal 12 volt power source as well as AC wall outlets. (I have one for my work provided laptop.)
----- Original Message ---- From: Clint Bradford clintbrad4d@earthlink.net To: Ben Jackson bbj@innismir.net Cc: amsat-bb@amsat.org Sent: Thursday, April 30, 2009 9:10:15 AM Subject: [amsat-bb] Re: Mobile Computer / Radio Installations
... I know for a fact that Dell, HP, and Acer all make car
chargers ...
Sorry - semantics coming into play. It's a little different "charging" versus "operating" ...
Clint Bradford _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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>> ... I know for a fact that Dell, HP, and Acer all make car chargers ...
Sorry - semantics coming into play. It's a little different "charging" versus "operating" ...
Only if the "car charger" supplies less power than the normal AC power supply. Otherwise, if the "car charger" supplies at least the same power level as the AC supply, then there is no issue of semantics. Look for DC-DC units that supply the same voltage and wattage as your AC power supply, and you should be in good shape. The laptop manufacturers sometimes have these DC-DC units, and there are after-market suppliers that can fill in if the laptop manufacturer doesn't have anything that works for your laptop.
The Acer Aspire One that N3TL and I (and a few others) have only uses a 30W AC supply that puts out 19 VDC. This is easy to address in a car charger. My old Dell Inspiron 8200 (mobile Pentium-4 CPU) laptop has a 110W AC power supply that puts out 16 VDC (I think - it is at home, and I'm not there). A laptop like this is a tough one to get a car charger/adapter for, due to the higher power requirement. I think I have seen one that would supply 90W or maybe 100W, but force the CPU to run at a slower clock rate - something supported in the mobile Pentium-4 CPU - to compensate for the high power consumption in that chip and dealing with smaller power supplies people might have to use with these laptops. With the netbooks, I don't have to lug that old Inspiron to hamfests or places unless I know there is AC power available and I need a second laptop with a larger screen.
N3TL mentioned having a 6-cell lithium-ion battery for his Acer netbook. This is now the standard pack supplied in later versions, where a 3-cell pack was originally supplied when I bought mine late last year. There are after-market lithium-ion packs that have 9 cells, which can run the Acer netbook for 6 to 8 hours depending on how many peripherals you have connected to USB ports and power requirements for those peripherals. I have one of these 9-cell packs, which makes this netbook very nice for hamfests and field operating. I had to order the pack from a Hong Kong-based online shop, since I could not find it anywhere stateside. It's worked perfectly since I received it in December.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
participants (7)
-
Ben Jackson -
Clint Bradford -
Mark Spencer -
n3tl＠bellsouth.net -
Nigel Gunn G8IFF/W8IFF -
Patrick STODDARD (WD9EWK/VA7EWK) -
Tim Tapio