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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Been there, done this already. I did
this exercise with Mike Powell a few years ago. Here’s the little
schematic he came up with. I tested it and works perfectly.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><img width=800 height=486 id="_x0000_i1027"
src="cid:image002.jpg@01C88DAA.04AB21A0"><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Alternatively, if you are doing several
lamps, then I would suggest the ULN2803A IC. It’s got 8 <st1:place
w:st="on">Darlington</st1:place> transistors each capable of sinking 500mA
each. The 20mA input line is the one coming from the MM5451, just replace
that with your input line. The Lamp Test part you can leave out as well,
but you do need the 2.2K pull up resistor if the output voltage is that to
drive an LED, otherwise you won’t trigger the transistor.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks to Mike Powell for the design.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Jay<o:p></o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
simpits-tech-bounces@simpits.org [mailto:simpits-tech-bounces@simpits.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Justin Messenger<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, March 24, 2008 10:22
AM<br>
<b><span style='font-weight:bold'>To:</span></b> simpits-tech@simpits.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [simpits-tech] controling
a 28v circuit with a 5v</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I thought about that and would be happy to go that route, but as Gene
said Im not sure if using only 20mA for the 5V would work well.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>As far as changing lamps goes, I want to control my landing gear
indicators, they are 28v but are not lamps. However, If I get them to work then
the same system would also work to control the 28v lamp that I also want
to function (gear transition light). This is a real sim and all the lamps are
28v and I have power going to them. I dont really want to modify them if I dont
have to due to common grounding.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><tt><font size=2 face="Courier New"><span style='font-size:
10.0pt'>yes you could run a realy?!</span></font></tt><font size=2
face="Courier New"><span style='font-size:10.0pt;font-family:"Courier New"'><br>
<tt><font face="Courier New">DU if the bulbs are re-lampable then just change
the stupid lamps!</font></tt><br>
<tt><font face="Courier New">Cris<o:p></o:p></font></tt></span></font></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<div id=RTEContent>
<p class=MsoNormal><font size=4 face="Arial Black"><span style='font-size:13.5pt;
font-family:"Arial Black";background:#00BF60'> Aviation Videos </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <a
href="http://HeritageAviationVideos.fly.to/">http://HeritageAviationVideos.fly.to/</a><o:p></o:p></span></font></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><strong><b><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>DC-8 Simulator</span></font></b></strong><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><a href="http://www.dc8cockpit.catisp.com">www.dc8cockpit.catisp.com</a><o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><strong><b><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>F-4 Simulators</span></font></b></strong><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
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</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
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target="_blank"></a><o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=1 width="100%" align=center>
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