REFLECTOR:A (re)volting problem
Laurence Coen
reflector@tvbf.org
Sun, 5 Oct 2003 12:23:17 -0500
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Chuck,
John is correct. A simple way to reduce the current is to add a =
resistor in series with the pitot heater. a 1 ohm resistor would reduce =
the current to 8 amps. Sounds like that would work but not really. =
First, you have added a smoking hot resistor that you would have to =
mount somewhere that doesn't set your plane on fire. Not only that but =
it would generate 2/3 of the heat produced while only 1/3 heats the =
pitot. It's simple, cheap and doesn't work.
I have looked at taking it apart and did not see how to do that. It =
looked like the inner section with the "guts" was brazed into the outer =
shell. If I knew someone with a 24 volt unit that would swap me for my =
12 volter that would be the simplest solution. The best solution IMOH =
is a switching regulator with temp. feedback to prevent meltdown even on =
the ground. this would, of course, be the most complex and not available =
unless I design and build it. My current plan is to finish my plane =
first.
Larry Coen
SE/RG Franklin
----- Original Message -----=20
From: John Dibble=20
To: reflector@tvbf.org=20
Sent: Saturday, October 04, 2003 6:30 PM
Subject: Re: REFLECTOR:A (re)volting problem
Chuck,=20
Shortening the wire will increase the heat output and current draw. =
Also that might overheat the wire and burn it up. Adding more wire =
(more resistance) will reduce heat output and current draw.=20
John=20
Chuck Jensen wrote:=20
Larry,Have you ever looked at yours or know how it =
assembles/disassembles. I've probably done so much jacking around with =
mine that it may be broke now, but your insight is interesting and will =
be useful in sorting it all out. When I get inside (if ever), I'll =
survey it with the idea of shortening the heating element/wire to reduce =
the heat output and draw. Note: Shortening in this application means =
de-lengthening. It may have all the "shortening" it needs. So, if you =
have even a clue how to get into that thing, please be nice and share. =
Chuck Jensen, in East Tennessee and not smart enough to get a picture =
past the website troll.-----Original Message-----=20
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On =
Behalf Of Laurence Coen=20
Sent: Saturday, October 04, 2003 12:24 PM=20
To: reflector@tvbf.org=20
Subject: Re: REFLECTOR:A (re)volting problem=20
=20
Chuck, I have the same unit, sans plating. The reason that the =
breaker pops is that the normal current is about 25 amps. The normal =
internal resistance is about 0.5 ohms. You need #10 wire and a 30 amp =
breaker to run that sucker. Larry CoenSE/RG Franklin PS: It only takes =
about 5 seconds on the ground to get it too hot to touch. I'm thinking =
of a voltage converter that reduces 12 volts to 6 volts.=20
----- Original Message -----
From: Chuck Jensen
To: 'reflector@tvbf.org'
Sent: Saturday, October 04, 2003 10:18 AM
Subject: RE: REFLECTOR:A (re)volting problem
From some Reflector postings and off-line comments, it seemed =
highly unlikely that there wouldn't be any markings on the "impossibly =
put together pitot". Apparently, in the plating process, enough metal =
was displaced that the only way to see the manufacturer's imprint was to =
position a light just-so and hold your mouth just right. On the plane, =
it looked perfectly smooth on both sides where the imprint was. It took =
a few attempts but I was able to glean the following =
information:Kollsman Mfr No. 369D-011AN5816-1, 12-16vPatent Canada, =
1940Patent No. 2.204.367 In checking the web, this AN5816-1 number =
corresponds to pitots used in some old warbirds, though it wasn't =
possible to tell which ones. More currently, that number was used in =
Aerostars and Piper Aztecs. It's called a "sharkfin pitot" due to the, =
well, sharkfin looking sail on the top of the pitot. Equally =
surprising, it truly is a 12v pitot, not 24v as I was told. The heavy =
current draw was from an internal short that became apparent as I did =
more testing; apparently incurred during the plating process. =
Nonetheless, Dave Black's, et al, discourse on epower and ecurrent was =
interesting and informative. I'll post a couple photos when I get the =
USB working again. However, anyone that has any idea in how to break =
into this thing would be most welcome to pass along suggestions. I =
really want to repair/salvage it if I can. On a different note, Jim now =
has me skeptical and fearful about flying near a cloud in a plastic =
plane. I'm ever so thankful for the many times I must have already =
cheated death's grip. My personal minimums have now gone up to 20,000 =
overcast with 10 mile visibility and low humidity!! Chuck Jensen, in =
East Tennessee where gaming Jim is the sport of the day.
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<DIV><FONT face=3DArial size=3D2>Chuck,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>John is correct. A simple way to =
reduce the=20
current is to add a resistor in series with the pitot heater. a 1 ohm =
resistor=20
would reduce the current to 8 amps. Sounds like that would work =
but not=20
really. First, you have added a smoking hot resistor that you =
would have=20
to mount somewhere that doesn't set your plane on fire. Not only =
that but=20
it would generate 2/3 of the heat produced while only 1/3 heats the =
pitot. =20
It's simple, cheap and doesn't work.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I have looked at taking it apart and =
did not see=20
how to do that. It looked like the inner section with the "guts" =
was=20
brazed into the outer shell. If I knew someone with a 24 volt unit =
that=20
would swap me for my 12 volter that would be the simplest =
solution. The=20
best solution IMOH is a switching regulator with temp. feedback to =
prevent=20
meltdown even on the ground. this would, of course, be the most complex =
and not=20
available unless I design and build it. My current plan is to =
finish my=20
plane first.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Larry Coen</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>SE/RG Franklin</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Daminetech@dixie-net.com =
href=3D"mailto:aminetech@dixie-net.com">John=20
Dibble</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, October 04, =
2003 6:30=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: REFLECTOR:A =
(re)volting=20
problem</DIV>
<DIV><BR></DIV>Chuck, <BR>Shortening the wire will increase the heat =
output=20
and current draw. Also that might overheat the wire and burn it=20
up. Adding more wire (more resistance) will reduce heat output =
and=20
current draw.=20
<P>John=20
<P>Chuck Jensen wrote:=20
<BLOCKQUOTE TYPE=3D"CITE">
<STYLE></STYLE>
<SPAN class=3D000260221-04102003><FONT face=3DArial><FONT =
color=3D#0000ff><FONT=20
size=3D-1>Larry,</FONT></FONT></FONT></SPAN><SPAN=20
class=3D000260221-04102003></SPAN><SPAN =
class=3D000260221-04102003><FONT=20
face=3DArial><FONT color=3D#0000ff><FONT size=3D-1>Have you ever =
looked at yours=20
or know how it assembles/disassembles. I've probably done so =
much=20
jacking around with mine that it may be broke now, but your insight =
is=20
interesting and will be useful in sorting it all=20
out. </FONT></FONT></FONT></SPAN><SPAN=20
class=3D000260221-04102003></SPAN><SPAN =
class=3D000260221-04102003><FONT=20
face=3DArial><FONT color=3D#0000ff><FONT size=3D-1>When I get inside =
(if ever),=20
I'll survey it with the idea of shortening the heating element/wire =
to=20
reduce the heat output and draw. Note: Shortening in this =
application=20
means de-lengthening. It may have all the "shortening" it =
needs. =20
S</SPAN><SPAN class=3D000260221-04102003>o, if you have even a clue =
how to get=20
into that thing, please be nice and=20
share.</FONT></FONT></FONT></SPAN> <FONT face=3DArial><FONT =
size=3D-1>Chuck=20
Jensen, in East Tennessee and not smart enough to get a picture past =
the=20
website troll.</FONT></FONT><FONT face=3DTahoma><FONT =
size=3D-1>-----Original=20
Message-----</FONT></FONT> <BR><FONT face=3DTahoma><FONT =
size=3D-1><B>From:</B>=20
reflector-admin@tvbf.org [<A=20
=
href=3D"mailto:reflector-admin@tvbf.org">mailto:reflector-admin@tvbf.org<=
/A>]<B>On=20
Behalf Of </B>Laurence Coen</FONT></FONT> <BR><FONT =
face=3DTahoma><FONT=20
size=3D-1><B>Sent:</B> Saturday, October 04, 2003 12:24 =
PM</FONT></FONT>=20
<BR><FONT face=3DTahoma><FONT size=3D-1><B>To:</B>=20
reflector@tvbf.org</FONT></FONT> <BR><FONT face=3DTahoma><FONT=20
size=3D-1><B>Subject:</B> Re: REFLECTOR:A (re)volting =
problem</FONT></FONT>=20
<BR> =20
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px"><FONT =
face=3DArial><FONT=20
size=3D-1>Chuck,</FONT></FONT> <FONT face=3DArial><FONT =
size=3D-1>I have=20
the same unit, sans plating. The reason that the breaker =
pops is=20
that the normal current is about 25 amps. The normal =
internal=20
resistance is about 0.5 ohms. You need #10 wire and a 30 amp =
breaker=20
to run that sucker.</FONT></FONT> <FONT face=3DArial><FONT=20
size=3D-1>Larry Coen</FONT></FONT><FONT face=3DArial><FONT =
size=3D-1>SE/RG=20
Franklin</FONT></FONT> <FONT face=3DArial><FONT size=3D-1>PS: =
It only=20
takes about 5 seconds on the ground to get it too hot to =
touch. I'm=20
thinking of a voltage converter that reduces 12 volts to 6=20
volts.</FONT></FONT>=20
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message =
-----</DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dcjensen@dts9000.com =
href=3D"mailto:cjensen@dts9000.com">Chuck=20
Jensen</A></DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
=
href=3D"mailto:'reflector@tvbf.org'">'reflector@tvbf.org'</A></DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, October =
04, 2003=20
10:18 AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> RE: REFLECTOR:A=20
(re)volting problem</DIV> <FONT face=3DArial><FONT =
size=3D-1>From some=20
Reflector postings and off-line comments, it seemed highly =
unlikely that=20
there wouldn't be any markings on the "impossibly put together=20
pitot". Apparently, in the plating process, enough metal =
was=20
displaced that the only way to see the manufacturer's imprint =
was to=20
position a light just-so and hold your mouth just right. =
On the=20
plane, it looked perfectly smooth on both sides where the =
imprint=20
was. It took a few attempts but I was able to glean the =
following=20
information:</FONT></FONT><FONT face=3DArial><FONT =
size=3D-1>Kollsman Mfr=20
No. 369D-011</FONT></FONT><FONT face=3DArial><FONT =
size=3D-1>AN5816-1,=20
12-16v</FONT></FONT><FONT face=3DArial><FONT size=3D-1>Patent =
Canada,=20
1940</FONT></FONT><FONT face=3DArial><FONT size=3D-1>Patent No.=20
2.204.367</FONT></FONT> <FONT face=3DArial><FONT =
size=3D-1>In checking=20
the web, this AN5816-1 number corresponds to pitots used in some =
old=20
warbirds, though it wasn't possible to tell which ones. =
More=20
currently, that number was used in Aerostars and Piper =
Aztecs. =20
It's called a "sharkfin pitot" due to the, well, sharkfin =
looking sail=20
on the top of the pitot. Equally surprising, =
it truly=20
is a 12v pitot, not 24v as I was told. The heavy current =
draw was=20
from an internal short that became apparent as I did more =
testing;=20
apparently incurred during the plating process. =
Nonetheless, Dave=20
Black's, et al, discourse on epower and ecurrent was interesting =
and=20
informative. I'll post a couple photos when I get the USB =
working=20
again. However, anyone that has any idea in how to break =
into this=20
thing would be most welcome to pass along suggestions. I =
really=20
want to repair/salvage it if I can.</FONT></FONT> <FONT=20
face=3DArial><FONT size=3D-1>On a different note, Jim now has me =
skeptical=20
and fearful about flying near a cloud in a plastic plane. =
I'm ever=20
so thankful for the many times I must have already cheated =
death's=20
grip. My personal minimums have now gone up to 20,000 =
overcast=20
with 10 mile visibility and low =
humidity!!</FONT></FONT> <FONT=20
face=3DArial><FONT size=3D-1>Chuck Jensen, in East Tennessee =
where gaming=20
Jim is the sport of the=20
=
day.</FONT></FONT></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></B=
ODY></HTML>
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