[App_rpt-users] Igologic i3386g Mini-ITX Power supply

[hwstar at rodgers.sdcoxmail.com]

> 
> From: "Mark Hergesheimer" <mark at hergesheimer.com>
> Date: 2009/04/21 Tue AM 10:23:50 PDT
> To: <sales at qrvc.com>
> CC: <app_rpt-users at qrvc.com>
> Subject: RE: [App_rpt-users] Igologic i3386g Mini-ITX Power supply
> 
> Mark Hergesheimer wrote:
> > Is there a packaged image for the Igologic i3386g Mini-ITX booting from
> the
> > CF card and using the URI that someone would be willing to share?
> > 
> > If so where would I find it? (I'm new to the list)
> > 
> >  
> > 
> > Steve had mentioned that the power supply for the IGoLogic i3386g Mini-ITX
> > should have an isolated ground and I found that the once the power supply
> > jack was unbolted from the case that the input ground was isolated from
> the
> > PC grounds. Would this be enough isolation to defeat the ground loop
> > problem?
> > 
> > Mark
> > 
> > _______________________________________________
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> 
> The image is located at http://limeylinux.org/downloads
> Look for the file: cfimg-i3386g-1.0.7-test.tar.gz
> 
> Regarding grounding, is there a problem or not as of right now?
> 
> ____________________________
> 
> Steve,
> 
> Thanks
> 
> The short answer is: No not yet.
> But I'm not at that point of testing yet. One of the things that attracted
> me to the IGoLogic pc was the ability to run directly from 13.8v. This helps
> with my diversity power system for the station. Per your email to me:
> 
> "Running an Embedded PC off of the same 13.8V source can be problematic due
> to ground loops. There needs to be galvanic isolation at the power supply or
> at the interconnect between the URI and the radio to reduce CPU noise
> currents being coupled into the audio lines from the shielding and signal
> return paths. The more powerful mini-ITX boards draw current in pulses which
> can cause the problem mentioned above.
> 
> Galvanically isolated means that there is no direct or indirect path to the
> ground (negative) terminal of the DC power source being used by the PC
> through the interconnect cable to the repeater for control and audio.
> Running the PC off of a 110VAC source eliminates this problem as AC power
> supplies are galvanically isolated for safety reasons."
> 
> I was trying to avoid a problem and so I discovered that the input to the
> IGoLogic power supply is actually isolated once the barrel connector was
> dismounted from the case and thus a possible cure for a problem that I
> really don't even have yet.

If this is one of the Andover units off of Ebay, just use a small 13.8VDC to 120VAC inverter coupled to the Travala "fat snake" PSU which came with it. This will provide the isolated ground you need. If you are running on battery power, then this setup is preferred due to the issue in the second paragraph below.

You can't hook 13.8V to directly to these Andover PC's as the power supply inside of them is only designed to accept 12V +/- 5%.

Steve
WA6ZFT






> 
> Mark
> 
> 
>