[H-GEN] Inverters and Computers

[Everist, Geoff]

Straight square wave form should be OK for a computer only power supply.


<TECHNO_BABBLE>

Most computer power supplies are switch mode, which rectify the incoming
ac, chop up the resulting dc and feed this into a transformer at high
frequency. This means much smaller, lighter, cheaper and less 'lossy'
transformers can be used for the voltage step down. So as the incoming
ac is rectified (converted to dc) anyway, it doesn't really matter
whether it is a 'clean'
sine or square wave (actually, a square wave is probably preferable).

</TECHNO_BABBLE>

Yes, it is an expensive way to go from 12Vdc to 240Vac to 5Vdc and
+/-12Vdc again, but it would be even more expensive to go directly from
12Vdc to 5,+/-12Vdc as this type of supply is not mass produced to the
extent of internal PC supplies and 12Vdc to 240Vac inverters.
Unfortunately, dc voltage conversion is not as straight forward as ac
conversion.

HTH,

Geoff Everist


> -----Original Message-----
> From:	Frank Brand [SMTP:fbrand at uq.net.au]
> Sent:	Sunday, February 14, 1999 9:17 PM
> To:	Humbug General
> Subject:	[H-GEN] Inverters and Computers
> 
> Anyone have any opinions,
> 
> A friend of mine wants to use his desktop computer in a mobile
> situation. He wants to obtain 240 V AC from an inverter.
> 
> He has three option viz,
> 
> 1. Sine Wave form (expensivest solution).
> 
> 2. Simulated sine wave ie. cropped sqare wave form (mid-cost
> solution).
> 
> 3. Square wave form (cheapest solution).
> 
> My question is - Can he save some money and obtain the sqare or
> simulated wave form inverters. Taking into account that the power so
> generated then goes through a transformer will the voltage cleanliness
> (? what the fsck do you think I mean by this) and voltage stability be
> sufficient for the computer to run OK?
> 
> Any ideas?
> 
> Seems an expensive way of going from 12V DC to 240 V AC to 5 V DC
> again
> doesn't it?
> 
> TIA.
> 
> --
> Frank Brand
> E-mail: fbrand at uq.net.au
> Home Page: http://www.uq.net.au/~zzfbrand
> 
> 
> 

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