MP3Car.com - View Single Post - Powering tablet PC straight from cig lighter power?

GizmoQ · 01-12-2007, 11:49 PM

You know when I first skimmed this article in my RSS reader, I went right by it cause I figured you had an OEM auto adapter and plugged it into the cig lighter. On the second perusal I realized this was not the case.

Let me start by saying, "Did you know computers run on smoke? Yea, when the smoke escapes, the computer quits running."

The above is what you have to look forward to if you continue as you are. I learned this lesson firsthand over twenty years ago and have never forgotten it, nor let my customers forget it. In a home/apartment/condo, etc if the lights dim when the heat or A/C comes on, this is called a brown-out condition (the main draw, A/C, takes so much power that other appliances recieve not enough power). Brown-outs kill computers over time. My little Commodore 64 back then smoked cause it wasn't protected by an appropriate over and under voltage surge protector (not all surge protectors are equal).

O.K. back to your situation - laptops and tablets are resilient but not this resilient. Sure it may run on 12-14 volts versus 19 volts, but this stresses the millions of diodes and transistors expecting a clean, constant voltage. It actually may run this way for up to a year, but sooner or later one or more of them will burn out - best case computer starts acting erratic and eventally power supply burns out/worst case you get a cascading failure (imagine dominoes one sparks causing the next to spark and so on), see the smoke, and it stops working all together.

Bottom line get the car adapter cut the cig lighter off the end and power it from an appropriate amperage fused line. I split mine off the ACC coming into the fuse box, added an inline fuse. When ACC shuts off, my tablet initiates its "on battery" power scheme, i.e., screen blanks after 1 min, at 20 mins it goes to standby, then at one hour it fires back up and hibernates. I've considered a startup controller but the "ON" button of my tablet is more accessible than the one on my head unit so its not too much trouble to turn it on when I get in.

Good luck whatever you decide, you have been warned.

01-12-2007, 11:49 PM	#3
GizmoQ FLAC GizmoQ's CarPC Specs Join Date: Nov 2004 Location: St Louis Vehicle: Several Posts: 1,318 My Photos: ()	You know when I first skimmed this article in my RSS reader, I went right by it cause I figured you had an OEM auto adapter and plugged it into the cig lighter. On the second perusal I realized this was not the case. Let me start by saying, "Did you know computers run on smoke? Yea, when the smoke escapes, the computer quits running." The above is what you have to look forward to if you continue as you are. I learned this lesson firsthand over twenty years ago and have never forgotten it, nor let my customers forget it. In a home/apartment/condo, etc if the lights dim when the heat or A/C comes on, this is called a brown-out condition (the main draw, A/C, takes so much power that other appliances recieve not enough power). Brown-outs kill computers over time. My little Commodore 64 back then smoked cause it wasn't protected by an appropriate over and under voltage surge protector (not all surge protectors are equal). O.K. back to your situation - laptops and tablets are resilient but not this resilient. Sure it may run on 12-14 volts versus 19 volts, but this stresses the millions of diodes and transistors expecting a clean, constant voltage. It actually may run this way for up to a year, but sooner or later one or more of them will burn out - best case computer starts acting erratic and eventally power supply burns out/worst case you get a cascading failure (imagine dominoes one sparks causing the next to spark and so on), see the smoke, and it stops working all together. Bottom line get the car adapter cut the cig lighter off the end and power it from an appropriate amperage fused line. I split mine off the ACC coming into the fuse box, added an inline fuse. When ACC shuts off, my tablet initiates its "on battery" power scheme, i.e., screen blanks after 1 min, at 20 mins it goes to standby, then at one hour it fires back up and hibernates. I've considered a startup controller but the "ON" button of my tablet is more accessible than the one on my head unit so its not too much trouble to turn it on when I get in. Good luck whatever you decide, you have been warned. __________________ *HARDWARE*: Fujitsu Stylistic 4121w/ WiFi & mini dock, Sierra Wireless Aircard 550, EXP PCMCIA Portable DVD-RW, Silabs FM, WinTV USB w/-26dB diversity antenna, XM Commander w/Timetrax USB, Delorme GPS, Saitek X-52 USB joystick, BluSoleil USB Bluetooth