[hpsdr] LPU Capacity

[Erich Heinzle]

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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