|
|
|
Author |
|
Message | |
|
happytechie
Joined: 24 Jan 2006 Posts: 408 Location: Surrey (at the mo.)
|
|
|
|
|
tahir
Joined: 28 Oct 2004 Posts: 45389 Location: Essex
|
|
|
|
|
Jonnyboy
Joined: 29 Oct 2004 Posts: 23956 Location: under some rain.
|
|
|
|
|
dougal
Joined: 15 Jan 2005 Posts: 7184 Location: South Kent
|
Posted: Wed Jun 28, 06 11:37 am Post subject: |
|
Thanks for posting that Paul, but there are a few considerations that folk should bear in mind.
In the UK, an Uninterruptable Power Supply (UPS), is less needed than in much of the USA and, I'd guess, Australia (source of the link), where the mains electricity might not be quite so reliable.
Although the author notes that computer psu's may not be too bothered about the waveform that comes off a UPS's inverter, I believe that screens are much more fussy.
Rather than go from 12v DC up to 240v AC with an expensive inverter and then use the computer psu to produce 5v and 12v DC, etc, its a very much better idea to start in a different place entirely, and bypass much of this expensive and inefficient conversion.
Use a laptop. (Sorts out any screen bothers).
Using a laptop that gives many hours of runtime from a normal size laptop battery means using a laptop that uses relatively little electrical power.
And its usually very easy (and cheap) to get a car charger (working from a cigarette lighter socket - or direct {fused} from a battery charged by renewables) to moderate between the car's 12v and whatever the laptop requires.
And then there's the normal reminder that car batteries, though cheap are designed, optimised, for a very different application. Their job is to deliver a massive current for a brief period, for engine starting. They are easily damaged by being drained (discharged, flattened) too far. Different, (less mass produced, and more heavily built and so more expensive) batteries called "deep discharge" lead/acid batteries are purpose built for usable charge/discharge capacity. They are as different as weightlifters and marathon runners.
Old car batteries are useful, but they aren't by any means first choice for their performance in this sort of application. |
|
|
|
|
|
Archive
Powered by php-BB © 2001, 2005 php-BB Group Style by marsjupiter.com, released under GNU (GNU/GPL) license.
|