[mythtv-users] Power bill vs SchedulesDirect bill

Robin Hill myth at robinhill.me.uk
Tue Sep 18 23:04:46 UTC 2007

On Tue Sep 18, 2007 at 04:42:31PM -0600, Bearcat M. Sandor wrote:

> So forgive this ignorant question, but if i have a 500 watt power supply
> does that mean that i'm using 500 watts all the time or that i have 500
> watts of power available?
The 500W is the maximum power output (I think it's output anyway - could
be input though) of the PSU.  You'll only use whatever's needed.

> If i use a 300 watt power supply am i consuming less power then i
> would if i had a 500 watt power supply?
Yes - the efficiency of a power supply drops off as the load falls
(they're designed to operate at nearly full loading).  Some of the newer
(and more expensive) PSUs hold up better at lower loads, but older PSUs
will usually drop off pretty rapidly below 80-90% loading.  You should
be able to get graphs of this from the manufacturers.

You will, of course, need to make sure the power supply is big enough
for your needs.  Remember to check on each power rail, not the total -
it's no good needing 100W at 5V when it only supplies 60.

    ( ' }     |       Robin Hill        <myth at robinhill.me.uk>  |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
Url : http://mythtv.org/pipermail/mythtv-users/attachments/20070919/678a951b/attachment.pgp 

More information about the mythtv-users mailing list