<br><font size=2 face="sans-serif">If a diode is a new point of failure, what's a regulator?</font>
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<td><font size=1 face="sans-serif"><b>"Tomanek, Wojtek" <tomanekw@saic-abingdon.com></b></font>
<br><font size=1 face="sans-serif">Sent by: discussion-request@nsrca.org</font>
<p><font size=1 face="sans-serif">03/31/2003 08:53 AM</font>
<br><font size=1 face="sans-serif">Please respond to discussion</font>
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<br><font size=1 face="sans-serif"> To: "'discussion@nsrca.org'" <discussion@nsrca.org></font>
<br><font size=1 face="sans-serif"> cc: </font>
<br><font size=1 face="sans-serif"> Subject: Re two batteries, was Miracle switch failures</font></table>
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<br><font size=2 color=#000080 face="Arial">Just FYI</font>
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<p><font size=2 color=#000080 face="Arial">I did use a similar two-battery system; the problem is that you have to find a high capacity diode (I used at least 1.5 Amp or higher, which is better). The voltage drop is 0.7 for silicon diodes, this works well with 5C batteries. However, using diodes introduces an additional single point of failure but having two independent systems balances this to some degree. </font>
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<p><font size=2 color=#000080 face="Arial">Now I use two batteries each with a switch and charging jack and no isolation between the two. The primary battery is a 5C (NiCd or NiMH) or Li-Ion with a 5.6 Volt regulator (other will work too 5.2 – 6.0 volt). The backup battery is a small 4C NiCd 250 mAh. Both switch connections plugged straight to the receiver. If you have to plug it through a Y with a secondary type servo (throttle or gear). </font>
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<p><font size=2 color=#000080 face="Arial">What happens in this system is that the primary battery chargers (equivalent to trickle charge) the secondary battery and keeps it at ~ 5.3 (with the 5.6 Volt regulator). If the primary battery fails the secondary will be enough to land, if the secondary fails the primary will do the landing duty. This assumes only an open circuit failures on a switch, plug, or even battery etc. I generally charge both batteries, but if I do not, I notice a little larger drain after the first flight on the primary battery (equivalent to two flights). </font>
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<p><font size=2 color=#000080 face="Arial">I always check both batteries before and after each flight that way the is less chance of a surprise. </font>
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<p><font size=2 color=#000080 face="Arial">This is not any better than other proposed systems, just what I have used for some time. </font>
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<p><font size=2 color=#000080 face="Arial">Good luck</font>
<p><font size=2 color=#000080 face="Arial">Wojtek</font>
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