[RFI] Car laptop adaptors

[Jim Brown]

On Sun, 11 Nov 2007 10:50:07 -0600, Jim P wrote:

>Just looked at the service info for an:

>      IBM Thinkpad 380ED (updated w/Win98)

>Reviewing the service manual the expected voltage
>range out of the AC mains/DC power supply itself
>(not necessarily the laptop's requirement) shows to
>be in the range of +14.5 to +17 VDC with 'tip'
>positive.

>I'm going to try Vbatt straight straight into this laptop
>because the inverter I've got is just too noisy on ten
>Meters even!

My experience is that my IBM T-series laptops run on a direct 
connection to the car if it's running. I've tried running them from 
a 12V battery (not being charged), and the charge regulator inside 
the laptop cycles between charge and discharge, so not ideal. So I'd 
say for these laptops at least, 14VDC is enough. 

73,

Jim K9YC