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<DIV><FONT face=Arial>Pro-Line battery packs were built this way as a
standard.</FONT></DIV>
<DIV> </DIV>
<DIV>Tony Stillman<BR>Radio South, Inc.<BR>3702 N. Pace Blvd.<BR>Pensacola, Fl
32505<BR><A
href="http://www.radiosouthrc.com">www.radiosouthrc.com</A><BR>800-962-7802</DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ev3464@sccoast.net href="mailto:ev3464@sccoast.net">Earl Vincent</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, March 29, 2003 6:22
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Re two batteries, was
Miracle switch failures</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Keith, the RCA engineer that I mentioned that
built my radios back in the 70's and set the battery packs up with the
diodes, name </FONT></DIV>
<DIV><FONT face=Arial size=2>was Ray Aikins, he was a big scale modeler back
then, I have not talked to him in years but he lives in Toms River, NJ. You
may</FONT></DIV>
<DIV><FONT face=Arial size=2>be able to find him on the net. </FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=tkeithb@attbi.com href="mailto:tkeithb@attbi.com">Keith Black</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, March 29, 2003 2:56
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Re two batteries, was
Miracle switch failures</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Bob, that sounds like a good solution.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Since the diode consumes some energy what
voltage is seen by the receiver? </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Do you just purchase a diode from an
electronics store and solder it in yourself, or is there one marketed
specifically for use in our applications (proper connectors
etc.).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Can you share the specifics of the one you use
(maybe even a model number and where you purchased it)?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks, </FONT></DIV>
<DIV><FONT face=Arial size=2>Keith</FONT></DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=WHIP23@aol.com href="mailto:WHIP23@aol.com">WHIP23@aol.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, March 28, 2003 5:00
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re two batteries, was
Miracle switch failures</DIV>
<DIV><BR></DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2
FAMILY="SANSSERIF"><BR>Ok third try, I must be e-mail challenged!!<BR><BR>
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TYPE="CITE">
<BLOCKQUOTE
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TYPE="CITE"><BR>Hi Guys<BR><BR>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px"
TYPE="CITE">All the "battery backup systems" I have seen put
something of unknown reliability/untested in the critical
path. The best setup is two batteries diode orred (sp?)
together (diode in each path from switch to receiver) through two
switches (must be 5 cell to allow for the diode drop) fully
redundant, you would have to have a failure in both paths at the
same time to loose control due to battery. Assuming you check
things every flight the odds of a failure in both paths is too
remote to consider. There is little weight penalty, run two
batteries 1/2 the size you would normally run. Being a worrier
I also make a point of never running either pack down too far (if I
happen to be running on one pack I want enough charge in that one
pack to last a long flight). The diodes must be in the path
from the switch to the receiver (if you put them between the battery
and the switch, as once got printed incorrectly, with MY name
attached, you won't be able to charge in this configuration)
I've been doing this for about 10 years with no problems and it has
saved me an airplane, both batteries good on take off one was bad
(open) on landing, if only one battery, bye bye airplane.
Guess you could argue that the bad battery might have been in
someone else's airplane VBG. It is a little more complex, two
switches (one of the biggest failure items) two charge jacks, two
batteries. Assuming you have an unused channel you can plug
the battery into any unused channel (preferred) if not then I would
wye it to a non mission critical channel, last choice would be to
wye the two batteries together (the wye is then mission critical, I
told you I was a worrier) There is also good evidence that the
diodes are not necessary, that a 5 cell pack won't charge a 4 cell
pack (one shorted cell), sounds right and I've used this scheme, but
I have never tested it with a cell shorted so I have no first had
experience. I'm not sure I could sleep at night, anymore, with
only one battery pack and switch, just seems like unnecessary
risk.<BR><BR>Flame suit on,
Bye<BR><BR>Bob<BR></BLOCKQUOTE><BR></BLOCKQUOTE><BR><BR></BLOCKQUOTE><BR></FONT><FONT
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