[hpsdr] LPU Capacity

[n3evl]

A couple of months ago I decided to retire LPU in favor of the 
picoPSU-120-WI-25.  This appears to fulfill the current requirements of 
the usual suspects + Metis at 1 Gigabit. The picoPSU spec quotes two 
figures for 5V:

5V 6A
5VSB 1.5A

I have no idea what 5VSB refers to - maybe somebody can shed some light 
on this designation?

The picoPSU unit is quite small and does not have the tall heatsinks 
used with LPU.   It supposedly runs quite a bit cooler but I left the 
fan in place figuring some air flow through Pandora can't hurt.

Pete, N3EVL

On 12/28/2011 10:03 AM, Chris Day wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
>
>
> Thanks, Erich. Replacing the soft fuses with wire has been enough so 
> far, but I haven't fired up the transmitter section of Pennylane yet. 
> Linear chain will be external, so there will be no extra load from 
> that. Meanwhile, playing with Mercury with delightful results.
>
> Chris Day
> AE6VK
>
>
> > Date: Wed, 28 Dec 2011 04:12:10 -0800
> > From: vk5hse at yahoo.com
> > To: hpsdr at lists.openhpsdr.org
> > Subject: Re: [hpsdr] LPU Capacity
> >
> > ***** High Performance Software Defined Radio Discussion List *****
> >
> > Have cobbled together various reflector postings for my own 
> reference as well as for others.
> >
> >
> > There was a summary posted to the reflector that is worth reviewing:
> >
> > 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2011-March/014678.html
> >
> > the meaty bits were:
> >
> > Magister = Ozy
> >
> >
> > power consumption summary:
> >
> >
> >                        12 V         5 v
> > OZY               .001  A        .1 A
> > PENY             .4 A           .2 A
> > MERC            .2  A          .5 A
> >
> > Metis 100                         .4A
> >
> > Metis 1000bT                   .75A
> >
> >
> > no-one seems to have stated excalibur power requirements, but it 
> doesn't appear to be huge
> >
> >
> > add the LPU errata document:
> >
> > http://www.tapr.org/pdf/LPU_Errata.pdf
> >
> > which mentions in errata #2:
> >
> > "Description of Error:
> > Fuses F2 and F3 are underrated for a full system. They are rated at 
> continuous 1.1A without
> > tripping, while an Ozy/Mercury/Penelope system draws typically 1.3A 
> from the +5V rail.
> >
> >
> > Symptoms:
> > An Ozy/Mercury/Penelope system will operate for a short period and 
> then unexpectedly shut
> > down. The time can vary, but is typically around 10 minutes. This is 
> due to F2 opening and shutting
> > down the +5V output. (Note that F2 doesn't actually "open"; it 
> becomes higher resistance to protect
> > the load.) After a power cycle, normal operation resumes.
> >
> >
> > Recommended Corrective Action:
> > Short across F2 and F3 with pieces of wire."
> >
> >
> >
> > There has also been talk of strapping the 12V feedtrhough for high 
> power things like a PA
> >
> > 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2010-July/012616.html
> >
> > and some suggestion of shorting the 5V fuse and relying on the 
> regulator to protect itself +/- modifying R6 the series resistor
> >
> > 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2010-July/012617.html
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