|
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
|
Re: [PLUG] 12 volt DC was Re: CD ripping
|
On Wed, 2002-09-18 at 17:22, multiple seriousity wrote:
> For anybody who uses stuff like this... or just has, or knows of something
> that can take a direct 12vdc Input... can you post model numbers?
By the way, for our robot, we considered one of three options:
1) Find an ATX power supply that ran from a 12VDC input. After some
searching, we found them, but the price (~$200 to $400) made it
unreasonable in our case. Here's an example:
http://www.portable-computer.com/ps/dc-48-volt-ps/dc-48-volt-ps.htm
(despite the URL, it also lists 12VDC input power supplies)
2) Build a power supply unit to provide the specific voltage levels
needed for the motherboard: 12V, 5V, 3.3V, and possibly some negative
voltage levels. Looking back, this probably would have been a good
choice, but we didn't have the electronics knowledge to do it at that
time.
3) Run at low efficiency (wasting critical battery time), and use a
120VAC ATX supply after an inverter. We did this because it was the
cheapest and the simplest.
But just to clear things up, a lead-acid or gel-cell battery doesn't run
always at 12V. Typically, when charged, it runs slightly higher,
towards 13V or more. However, it's not unusual to see the battery
around 14V when the car is running and the alternator is turning. So
don't think that this is a clean 12VDC source. It's probably more like
14V, and only after you start the engine (and much lower temporarily
while starting because of the excessive current draw of the starter
motor). So a word of caution: don't be so quick to try these things
with electronics very sensitive to a clean 12V source.
Michael F. Robbins
mike@gamerack.com
_________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
Announcements - http://lists.netisland.net/mailman/listinfo/plug-announce
General Discussion -- http://lists.netisland.net/mailman/listinfo/plug
|
|