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Mini-ITX
http://solar-guppy.com/forum/viewtopic.php?f=10&t=163
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Author:  Solar Guppy [ Sat Feb 14, 2004 2:49 pm GMT EthGMT ]
Post subject:  Mini-ITX

I found the via document that has the power information on the mini-itx line. The via.tw site takes forever , so I have copied it to this server for anyone who would like to take a look at it

VIA Mini-itx power document

Author:  mattl [ Wed Jun 09, 2004 12:17 pm GMT EthGMT ]
Post subject: 

thought i may add a bit to the mini-itx subject for those interested in low power pc's.

i run the latest m10000 i bought a few months ago and performance is great but power is a good bit more than solar guppy's 11 watts.

i run suse linux, and just found a GREAT ability in linux's acpi functions to throttle the CPU down to 1/2 speed. Ive yet to measure power usage.
this is great as its a 24/7 website like mr guppy and 90% of the 24 hours a day its just a webserver, where the speed at 1/2speed is sufficient.
(http://lamplight.no-ip.org)
unfortunately im running my pc from a small xantrex 300w interter and then through an ac/dc adapter, as the pc's dc power supply cant handle the voltage fluctuations of the lead acid batteries. i estimate the pc's using a varying 30-about 40 average watts in this unoptimized configuration. (dc/ac/dc). I did just order a PW60 which is supposedly rated for up to 14.8v (i only go to 14.6v). once i get that i intend to directly measure voltages of the pc, with and without cpu throttling.. ill be sure to report back. im continuously looking into lowering power usage on linux.. nmot as easy as windows i must admit. but you cant beat the price and feature set

Author:  Solar Guppy [ Wed Jun 09, 2004 1:00 pm GMT EthGMT ]
Post subject: 

Your "guestimating" your power usage and you have way to many things in the loop to know for sure what is causing your usage and exactly what is being consumed

My 600mHz unit , using a laptop drive running disk tests peaks at 13 watts , this is with a Fluke 41 power analyzer. This seems to match Via's doc (on this site) of about 5-6 watts the cpu burns


get a watts-up type power plug meter , that should give you a true idea of the power your using

Author:  mattl [ Wed Jun 09, 2004 2:17 pm GMT EthGMT ]
Post subject: 

my guesstimates are based on what gets put back into my batteries each day as its often the only thing running off my pv. also in conjunction with watching my mx60 after float gives me a pretty good idea.

it runs approximately 3amps @12v. i want to measure it inline with my dmm once i get switched over to straight dc, that oughta be fun.

thanks though, not interested in getting overly detailed about it. but i will post what i get if anyones interested like i said

Author:  Solar Guppy [ Wed Jun 09, 2004 5:02 pm GMT EthGMT ]
Post subject: 

The MX60 display is not very accurate ... And you have charge/float losses as well

The DVM inline is a good cheap way to know for sure ...

I'm only doggin you since your making claims about somthing without data ... At these power levels .. the battery losses are probably 1/2 to 2/3rd of your draw , not the mini-itx

Also , the MX60 is powered 24/7 off the battery ... thats some watts there as well !

Author:  bob [ Thu Jun 10, 2004 10:10 pm GMT EthGMT ]
Post subject: 

>>The MX60 display is not very accurate

The MX60s input (PV) current display is for reference only and is a calculated number based on the output current (which will be more
accurate). Watts displayed on the main screen are also based on Output (battery) current. Measurements can be worse at very low wattages.

>>Also , the MX60 is powered 24/7 off the battery ... thats some watts there as well !

This is true. At night, the power is about a watt. Select "auto" for the backlight if you're trying for the lowest night loss. When the MX is operating, the power draw will go up with increasing PV voltage. Minimum power when in operation (relays on, etc.) is about 4.5 Watts.

boB

Author:  Solar Guppy [ Thu Jun 10, 2004 10:21 pm GMT EthGMT ]
Post subject: 

Hi boB,

Matt was using the MX display as the "Gauge" to the Mini-itx power draw.

My intent wasn't to knock the MX60 , more to the point , its not a low-power watt meter and matt over looked the fact the MX60 is a 24/7 load


Matt can use a Watts-Up or cheap DC current meter ... but it should show power is the sub-20 watt range with a laptop drive

Henry

Author:  glenn.burt [ Mon Jun 14, 2004 3:37 pm GMT EthGMT ]
Post subject:  Mini-ITX Update

Just a brief update on the system I built:

It is runing MS SBS 2003 with no problems - a little slow when operating from the server, but acceptable.

I did connect it in parallel with my Linksys router, and with my laptop in parallel as well (to run a packet sniffer). all 3 devices received IP addresses from the RR servers with no trouble, and I have not gotten a bill for any other charges. BTW, the cable modem does not have an IP address, so it has no bearing on the DHCP question.

I have not yet measured the power - still using the OEM brick - I have it plugged into my UPS, and it is not easily accessable to get a Kill-a-Watt back there.

More as I develop it!
Glenn

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