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I power my
ham shack equipment from a sealed deep cycle
marine battery. The picture above
is my
Battery Condition Monitor which I
build up using 3-1/2 LCD digital
panel meters.
It will cost you about $75.00 to
build this Battery monitor.
You may
order all the parts necessary from
two sources.
The meters and
enclosure from Circuit Specialists.
www.web-tronics.com
Two
model PM-128E digital meters $12.25
each. One model EM-02 case, $17.69.
All
other necessary parts from Bosque
Communications, Inc.
HAMPAL Battery Monitor Kit, $18.00
email
bci@w5ncd.com
* You
furnish your own Deep Cycle
Battery.
Hand
tools necessary to complete this
project include small soldering
iron, long nose pliers,
diagonals,
screwdrivers, file, Exacto knife, and
nibbling tool.
Click here to view and print
Circuit diagram.
Click here to view and print Front
and rear panel drilling guide.
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Nibbling Tool |
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Using a nibbling tool you can cut the two meter holes in about 30 minutes |
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Hampal Parts Kit |
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All the parts you need except the two meters and the housing. |
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Meter Shunt |
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I wound the 48" meter shunt on a 3/4" dowel rod. |
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Inside the Rear Panel |
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Notice layout of wiring and voltage regulator. |
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External View |
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of the front and rear panels. |
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Top View |
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with cover removed. |
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The PM-128E digital meter maybe
programmed to operate from a 5 volt
or 9 volt power source. Since we
are going to monitor a 12 volt
battery I use a LM7805 regulator to
obtain the 5 volts necessary to
operate the digital meters. The
meters are programmable with
jumpers to read AC or DC voltage
and to set the decimal point of the
readout. Jumpers are selected for
DC and 2 place decimal points on
both meters. The meter to monitor
the 12 volt battery is programmed
to read 20 volts. The meter to read
the current (AMPS) is programmed to
read 200mV. Reading the voltage
drop across a 0.01 ohm meter shunt
made from a 4 foot length of 14
gauge house wire, this meter is now
a 20 amp meter. The accuracy is +/-
0.8%. The digital meter comes with
a one page owners manual. Read and
study this information carefully
before installing jumpers. | 
