Today's Message Index:
----------------------
1. 11:41 AM - Re: Contactors (jan)
2. 02:27 PM - Re: Contactors (Bill Allen)
3. 04:16 PM - Re: Contactors (Matt Prather)
4. 05:32 PM - Aviation intercom (Roger & Jean)
5. 10:12 PM - Re: Contactors (Sacha)
6. 10:21 PM - Re: Contactors (Bob Verwey)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Hi Bob,
It will be very interesting to hear what you find out about EMC if you get
the chance to do it ...
I will be very interesting to hear more about your contactor cooler circuit
/ module when you have it available ... will be ideal for a generic
contactor
All the best
Jan
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: 30 October 2013 00:30
Subject: RE: AeroElectric-List: Contactors
At 04:44 PM 10/29/2013, you wrote:
What about using a Kilovac EV200 with a circuit saver ? Any experience with
them ?? They pull in under high A.. then the circuit saver lowers the
current to hold the relay closed... (but I am told the circuit saver is
'noisy' ... i.e. lots of EMC ...)
Anyone have any comments ??
A fine contactor with a price to match . . .
and yes . . . pwm management of holding
current is not noise free. Most users
have not found the noise to be a problem.
I think I've got an EV200 in the skunk-werks
box of goodies somewhere . . . if I can put
my hands on it, I'll see if I can get the
EMC lab gurus to do a quick conducted survey
on it.
We'll have a contactor-cooler product available
pretty soon. The 9024 4-function module will
include that capability. I'll it checked for
conducted emissions too. The goal would be
to offer a low cost alternative to lowering
operating current (and temperature rise) on
the generic contactors. Reduced operating
temp should improve on what has already been
a good service life.
But aside from weight and cost, the EV200 is
a fine opportunity for increased service life
assuming you find $value$ in the exchange.
Bob . . .
<http://www.matronics.com/Navigator?AeroElectric-List>
<http://www.matronics.com/contribution>
<html xmlns:v="urn:schemas-microsoft-com:vml"
xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:w="urn:schemas-microsoft-com:office:word"
xmlns:st1="urn:schemas-microsoft-com:office:smarttags"
xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html;
charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]--><o:SmartTagType
namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PersonName"/>
<!--[if !mso]>
<style>
st1\:*{behavior:url(#default#ieooui) }
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:blue;
text-decoration:underline;}
p
{mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman";}
pre
{margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=EN-US link=blue vlink=blue>
<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span
style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi <st1:PersonName
w:st="on">Bob</st1:PersonName>,<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'>It will be very interesting to
hear what
you find out about EMC if you get the chance to do it
…<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'>I will be very interesting to hear
more
about your contactor cooler circuit / module when you have it available
…
will be ideal for a generic contactor <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'>All the
best<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'>Jan<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>
<div>
<div class=MsoNormal align=center style='text-align:center'><font
size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<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'>
owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Robert L. Nuckolls,
III<br>
<b><span style='font-weight:bold'>Sent:</span></b> 30 October 2013
00:30<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName
w:st="on">aeroelectric-list@matronics.com</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE:
AeroElectric-List:
Contactors</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:
12.0pt'>At 04:44 PM 10/29/2013, you wrote:<br>
<br>
<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'>What about using a Kilovac EV200
with a
circuit saver ? Any experience with them ?? They pull in under
high A..
then the circuit saver lowers the current to hold the relay
closed… (but
I am told the circuit saver is ‘noisy’ … i.e. lots of
EMC
…)<br>
<br>
Anyone have any comments ??</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:
12.0pt'><br>
A fine contactor with a price to match . . .<br>
and yes . . . pwm management of holding<br>
current is not noise free. Most users<br>
have not found the noise to be a problem.<br>
I think I've got an EV200 in the skunk-werks<br>
box of goodies somewhere . . . if I can put<br>
my hands on it, I'll see if I can get the<br>
EMC lab gurus to do a quick conducted survey<br>
on it.<br>
<br>
We'll have a contactor-cooler product available<br>
pretty soon. The 9024 4-function module will<br>
include that capability. I'll it checked for<br>
conducted emissions too. The goal would be<br>
to offer a low cost alternative to lowering<br>
operating current (and temperature rise) on<br>
the generic contactors. Reduced operating<br>
temp should improve on what has already been<br>
a good service life.<br>
<br>
But aside from weight and cost, the EV200 is<br>
a fine opportunity for increased service life<br>
assuming you find $value$ in the exchange.<br>
<br>
<br>
<o:p></o:p></span></font></p>
<x-sigsep>
<p></x-sigsep><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>
<st1:PersonName w:st="on">Bob</st1:PersonName> . . .
<o:p></o:p></span></font></p>
<pre><b><font size=2 face="Courier New"><span
style='font-size:10.0pt;
font-weight:bold'><o:p> </o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
style='font-size:10.0pt;font-weight:bold'><o:p> </o:p></span></fo
nt></b></pre><pre><b><font
size=2 face="Courier New"><span
========================
========================
===<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
; - The AeroElectric-List Email Forum
-<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
List Features Navigator to
browse<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
utilities such as List
Un/Subscription,<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
Download, 7-Day Browse, Chat,
FAQ,<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
much more:<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
t></b></pre><pre><b><font
size=2 face="Courier New"><span
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www
.matronics.com/Navigator?AeroElectric-List</a><o:p></o:p></span></font>
</b></pre><pre><b><font
size=2 face="Courier New"><span
t></b></pre><pre><b><font
size=2 face="Courier New"><span
========================
========================
===<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
; -
MATRONICS WEB FORUMS -<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
also available via the Web
Forums!<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
t></b></pre><pre><b><font
size=2 face="Courier New"><span
href="http://forums.matronics.com">http://forums.matronics.com</a><o:p
></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
t></b></pre><pre><b><font
size=2 face="Courier New"><span
========================
========================
===<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
; - List Contribution
Web Site -<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
your generous support!<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
;  
;  
; -Matt Dralle, List
Admin.<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
href="http://www.matronics.com/contribution">http://www.matronics.com/
contribution</a><o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
========================
========================
===<o:p></o:p></span></font></b></pre><pre><b><font
size=2 face="Courier New"><span
style='font-size:10.0pt;font-weight:bold'><o:p> </o:p></span></fo
nt></b></pre></div>
<pre><b><font size=2 color="#000000" face="courier new,courier">
</b></font></pre></body></html>
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Hi Bob,
You wrote;
<<Okay, you've got a 15a current budget . . . 5A of
rated output should be 'walled off' for battery
recharging in flight . . . and remember, the SD-20
doesn't give you any useful output until you're airborne.>>
Noted.
<< So do all the math. Get this form http://tinyurl.com/7jqypwj and do an
inventory of every electrical load . . . including the battery contactor.Don't
fuss with bus-decisions yet, just get a read on total loads under
various flight
conditions.>>
Got the form. Willdo.
<<Surely your anticipated system can function with the battery
contactoropen . . . whether
it opens from failure or the fact that you shut it off, getting to an
airport of intended destination shouldn't be a foreboding task.>>
Presumably that's what the e-bus is there for in your designs, if not the
architecture of Mr.Piper in 1966, when my PA30 was built.
<< Do you have a flight-bag back-up? http://tinyurl.com/lg3n4gh >> Yes I
do.
<< I'd also give pretty good odds that the contactor you replaced had been
in service for a considerable period of time >>
I have no reason to doubt it was new with the aircraft, in 1966.
What I've learnt from this is to actually measure the current used by
each of the consumers one plans to use.
<<That's never wrong. When you get all the numbers, give
us a list of your findings. Add 'em all up and see if you've busted your
15A
bubble. Running loads only, intermittent loads like
flap motors, trim motors, transmitters, etc are
not significant energy consumers.>>
Will do.
Thanks.
Bill Allen
**
**
On 30 October 2013 02:22, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 08:28 AM 10/29/2013, you wrote:
>
> Hi Bob,
>
> Thanks for the reply.
>
> 1. Yes, well caught, the B&C SD20 fits on the vacpad not the mag location.
> My mis-type. - trying to colour in one point (the draw of the master relay)
> and not paying attention to the details. I'm using a Pmag-E and an LSE
> as ignition systems.
>
>
> Okay, you've got a 15a current budget . . . 5A of
> rated output should be 'walled off' for battery
> recharging in flight . . . and remember, the SD-20
> doesn't give you any useful output until you're airborne.
>
> 2. Your tests showing the real draw on the master solenoid are very
> revealing, presuming that the master solenoid I have from Aircraft Spruce (http://www.aircraftspruce.com/catalog/elpages/masterrelay.php?clickkey=10293) is a Cole-Hersee - I'm unfamiliar with the term but gather from googling
> that they are to solenoids what Hoover is to vacuum cleaners.
>
> However, 0.8amps is still almost the equivalent of a Garmin 430 (0.2a
> stby), Funkwerk Com (0.1a stby),DynonXPDR-262 (0.15a stby) and AeroLED
> Navlights (0.4a). All are "brochure figures" unless I've misread them.
>
>
> So do all the math. Get this form
>
> http://tinyurl.com/7jqypwj
>
> and do an inventory of every electrical
> load . . . including the battery contactor.
> Don't fuss with bus-decisions yet, just
> get a read on total loads under various
> flight conditions.
>
>
> 3. The failure I experienced on my PA30 was on the ground. I found a
> totally dead system with a good battery, and traced it quickly to the
> master relay not activating. A new unit fixed it, and upon stripping the
> old one, I found moisture penetration of the internals to be the cause.
> Cleaning it up got it working again, but not to the point that I wanted to
> risk the disruption it could cause if it failed again.to
>
>
> Surely your anticipated system can function
> with the battery contactor open . . . whether
> it opens from failure or the fact that you
> shut it off, getting to an airport of intended
> destination shouldn't be a foreboding task.
>
>
> Had it failed in flight I would not have lost engine power, but would have
> lost all ships power, unless there is an e-bus on a 1966 PA30 that I'm not
> aware of, which is possible.
>
>
> No, they don't have that feature . . . but if
> it were my airplane . . . it would.
>
> Do you have a flight-bag back-up?
>
> http://tinyurl.com/lg3n4gh
>
>
> If you'd like me to mail it to you for dissection, I can do that.
>
>
> Not useful at this stage. The major point is that
> it failed on the ground. I won't say that failures
> in fight never happen . . . but they are exceedingly
> rare. If one has failed in flight, I'd give pretty
> good odds that the pilot was 'warned' . . . probably
> conducted more than one flight where the contactor
> had to be 'jiggered' in some way before the panel lit
> up . . . and he doesn't even know what an e-bus is.
>
> I'd also give pretty good odds that the contactor
> you replaced had been in service for a considerable
> period of time.
>
> I'm supposed to get a networked computer at Cessna
> on Monday. I'd should be able to search the archives
> for history on part numbers used for both production
> and spares on the single engine line going back a
> very long way.
>
>
> 4. What I've learnt from this (ie, point 2 above) is to actually measure
> the current used by each of the consumers one plans to use.
>
>
> That's never wrong. When you get all the numbers, give
> us a list of your findings.
>
>
> If the acceptance of 2amps for the master relay (but actually 0.8amps) is
> read across in this way for all other units, it's easily possible to end up
> with an alternator, wires, switches, fuses etc all way oversize and
> overweight.
>
>
> That's not typical. I've never seen a value greater
> than 1.0A assigned to battery contactors on single
> engine airplanes. Further, the numbers from installation
> manuals on items used in TC aircraft should be golden.
> Updating load analysis and weight and balance for
> any changes to an airplane is pretty much a given for
> which the manufacturer is obligated to support with
> good numbers.
>
> Add 'em all up and see if you've busted your 15A
> bubble. Running loads only, intermittent loads like
> flap motors, trim motors, transmitters, etc are
> not significant energy consumers.
>
> **
>
> ** Bob . . .
>
> *
>
> *
>
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Seems like the relay (contactor) that draws 0.8-2A (depending on how it's
measured) is one that is sized to be capable of carrying starter currents
(though not necessarily capable of switching them reliably). An
architecture that uses such a contactor for all devices is probably fine
when you have 40A+ to play with. But, in an application where you're on a
tight energy budget, maybe it would make sense to have parallel
contactors/relays. A smaller relay might be able to handle everything but
starting current, and only consume 100-200mA to do it. The heavy one would
only be energized when starting the engine. It may break the architecture
goal of running the B-lead current through the heavy starter wire, but that
may still be a good deal.
Regards,
Matt-
On Thu, Oct 31, 2013 at 3:26 PM, Bill Allen <billallensworld@gmail.com>wrote:
> Hi Bob,
>
> You wrote;
>
> <<Okay, you've got a 15a current budget . . . 5A of
> rated output should be 'walled off' for battery
> recharging in flight . . . and remember, the SD-20
> doesn't give you any useful output until you're airborne.>>
>
> Noted.
>
> << So do all the math. Get this form http://tinyurl.com/7jqypwj and do
> an inventory of every electrical load . . . including the battery
> contactor.Don't fuss with bus-decisions yet, just get a read on total
> loads under various flight conditions.>>
>
> Got the form. Willdo.
>
> <<Surely your anticipated system can function with the battery contactoropen
. . . whether
> it opens from failure or the fact that you shut it off, getting to an
> airport of intended destination shouldn't be a foreboding task.>>
>
> Presumably that's what the e-bus is there for in your designs, if not the
> architecture of Mr.Piper in 1966, when my PA30 was built.
>
>
> << Do you have a flight-bag back-up? http://tinyurl.com/lg3n4gh >> Yes
> I do.
>
>
> << I'd also give pretty good odds that the contactor you replaced had
> been in service for a considerable period of time >>
>
> I have no reason to doubt it was new with the aircraft, in 1966.
>
> What I've learnt from this is to actually measure the current used by
> each of the consumers one plans to use.
>
> <<That's never wrong. When you get all the numbers, give
> us a list of your findings. Add 'em all up and see if you've busted
> your 15A
> bubble. Running loads only, intermittent loads like
> flap motors, trim motors, transmitters, etc are
> not significant energy consumers.>>
>
>
> Will do.
>
> Thanks.
>
> Bill Allen
>
>
> **
>
> **
>
>
> On 30 October 2013 02:22, Robert L. Nuckolls, III <
> nuckolls.bob@aeroelectric.com> wrote:
>
>> At 08:28 AM 10/29/2013, you wrote:
>>
>> Hi Bob,
>>
>> Thanks for the reply.
>>
>> 1. Yes, well caught, the B&C SD20 fits on the vacpad not the mag
>> location. My mis-type. - trying to colour in one point (the draw of the
>> master relay) and not paying attention to the details. I'm using a
>> Pmag-E and an LSE as ignition systems.
>>
>>
>> Okay, you've got a 15a current budget . . . 5A of
>> rated output should be 'walled off' for battery
>> recharging in flight . . . and remember, the SD-20
>> doesn't give you any useful output until you're airborne.
>>
>> 2. Your tests showing the real draw on the master solenoid are very
>> revealing, presuming that the master solenoid I have from Aircraft Spruce (http://www.aircraftspruce.com/catalog/elpages/masterrelay.php?clickkey=10293) is a Cole-Hersee - I'm unfamiliar with the term but gather from googling
>> that they are to solenoids what Hoover is to vacuum cleaners.
>>
>> However, 0.8amps is still almost the equivalent of a Garmin 430 (0.2a
>> stby), Funkwerk Com (0.1a stby),DynonXPDR-262 (0.15a stby) and AeroLED
>> Navlights (0.4a). All are "brochure figures" unless I've misread them.
>>
>>
>> So do all the math. Get this form
>>
>> http://tinyurl.com/7jqypwj
>>
>> and do an inventory of every electrical
>> load . . . including the battery contactor.
>> Don't fuss with bus-decisions yet, just
>> get a read on total loads under various
>> flight conditions.
>>
>>
>>
>>
>> 3. The failure I experienced on my PA30 was on the ground. I found a
>> totally dead system with a good battery, and traced it quickly to the
>> master relay not activating. A new unit fixed it, and upon stripping the
>> old one, I found moisture penetration of the internals to be the cause.
>> Cleaning it up got it working again, but not to the point that I wanted to
>> risk the disruption it could cause if it failed again.to
>>
>>
>> Surely your anticipated system can function
>> with the battery contactor open . . . whether
>> it opens from failure or the fact that you
>> shut it off, getting to an airport of intended
>> destination shouldn't be a foreboding task.
>>
>>
>> Had it failed in flight I would not have lost engine power, but would
>> have lost all ships power, unless there is an e-bus on a 1966 PA30 that I'm
>> not aware of, which is possible.
>>
>>
>> No, they don't have that feature . . . but if
>> it were my airplane . . . it would.
>>
>> Do you have a flight-bag back-up?
>>
>> http://tinyurl.com/lg3n4gh
>>
>>
>>
>>
>> If you'd like me to mail it to you for dissection, I can do that.
>>
>>
>> Not useful at this stage. The major point is that
>> it failed on the ground. I won't say that failures
>> in fight never happen . . . but they are exceedingly
>> rare. If one has failed in flight, I'd give pretty
>> good odds that the pilot was 'warned' . . . probably
>> conducted more than one flight where the contactor
>> had to be 'jiggered' in some way before the panel lit
>> up . . . and he doesn't even know what an e-bus is.
>>
>> I'd also give pretty good odds that the contactor
>> you replaced had been in service for a considerable
>> period of time.
>>
>> I'm supposed to get a networked computer at Cessna
>> on Monday. I'd should be able to search the archives
>> for history on part numbers used for both production
>> and spares on the single engine line going back a
>> very long way.
>>
>>
>>
>> 4. What I've learnt from this (ie, point 2 above) is to actually measure
>> the current used by each of the consumers one plans to use.
>>
>>
>> That's never wrong. When you get all the numbers, give
>> us a list of your findings.
>>
>>
>>
>> If the acceptance of 2amps for the master relay (but actually 0.8amps)
>> is read across in this way for all other units, it's easily possible to end
>> up with an alternator, wires, switches, fuses etc all way oversize and
>> overweight.
>>
>>
>> That's not typical. I've never seen a value greater
>> than 1.0A assigned to battery contactors on single
>> engine airplanes. Further, the numbers from installation
>> manuals on items used in TC aircraft should be golden.
>> Updating load analysis and weight and balance for
>> any changes to an airplane is pretty much a given for
>> which the manufacturer is obligated to support with
>> good numbers.
>>
>> Add 'em all up and see if you've busted your 15A
>> bubble. Running loads only, intermittent loads like
>> flap motors, trim motors, transmitters, etc are
>> not significant energy consumers.
>>
>> **
>>
>> ** Bob . . .
>>
>> *
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>> *
>>
>>
> *
>
> *
>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Aviation intercom |
Does anyone have the schematic or Manual for the WGA Model AIR-1177
Aviation Intercom System? I am trying to figure out the input and
output jacks on the box. I intend to mount it in a panel along with an
isolation amp.
Roger
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I use automotive "cube" relays (one for the master relay, one for alternator) rated
at 70A. They are light and consume less than 300mA each. Is there a reason
not to use them? The only potential drawback I'm aware of is that they can
break the contact if subject to violent shocks. But loosing panel power for a
few milliseconds doesn't seem such a big issue (the autopilot does reset but then
in such violent turbulence you might be hand flying the thing in any case,
and the GNS430 doesn't even notice any absence of power that lasts that little).
Are there other risks I am not considering here? This is a VFR only machine and
I'm a low time PPL so not the most experienced in these matters.
Sacha
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Sacha,
I have used one of these Bosch 70amp relays for the master in my
experimental Bonanza for the past 8 years - rock solid! I still use the
caveman relay for the starter.
Bob Verwey
A35 ZU-DLW
On 1 November 2013 07:10, Sacha <uuccio@gmail.com> wrote:
>
> I use automotive "cube" relays (one for the master relay, one for
> alternator) rated at 70A. They are light and consume less than 300mA each.
> Is there a reason not to use them? The only potential drawback I'm aware
> of is that they can break the contact if subject to violent shocks. But
> loosing panel power for a few milliseconds doesn't seem such a big issue
> (the autopilot does reset but then in such violent turbulence you might be
> hand flying the thing in any case, and the GNS430 doesn't even notice any
> absence of power that lasts that little).
>
> Are there other risks I am not considering here? This is a VFR only
> machine and I'm a low time PPL so not the most experienced in these matters.
>
> Sacha
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|