Today's Message Index:
----------------------
1. 01:59 AM - How to Toggle Speed Brakes with Momentary On Switch? (GLEN MATEJCEK)
2. 05:52 AM - Re: How to Toggle Speed Brakes with Momentary On Switch? (Eric M. Jones)
3. 07:20 AM - Change to Shottky? (Roger Evenson)
4. 08:15 AM - Re: How to Toggle Speed Brakes with Momentary On Switch? (Eric M. Jones)
5. 08:50 AM - Re: Change to Shottky? (Jeff Luckey)
6. 11:21 AM - Re: Change to Shottky? (Thomas Blejwas)
7. 07:05 PM - ELT Antenna (msmeredith)
8. 07:55 PM - Re: ELT Antenna (The Kuffels)
9. 08:30 PM - Re: ELT Antenna (Stuart Hutchison)
Message 1
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| Subject: | How to Toggle Speed Brakes with Momentary On Switch? |
****SNIP****
From: Eric Page <edpav8r@yahoo.com>
..... Airplanes have no momentary bi-stable switches.
>
> Eric M. Jones
The overhead panel of the airplane I fly at work is littered with both
momentary
contact and bi-stable latching switchlights. ...
****SNIP****
Same for me and several A/C types I've flown.
Message 2
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| Subject: | Re: How to Toggle Speed Brakes with Momentary On Switch? |
Bi-stable switches?
That isn't to say it's a good design. I suppose some allowances can be made, but
the basic principle applies:
Switch Design 101:
"Each switch is to be labled describing its function. The condition of the switch
must be apparent from its mechanical position, whether or not power is applied."
One could allow ignoring this principle for switches that:
a) Don't matter if the power is out and then present no surprises if the power
is turned on.
b) Don't affect safety.
c) Etc.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416889#416889
Message 3
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| Subject: | Change to Shottky? |
I wired Z11 with the earlier recommended endurance bus diode w/15 watt heatsink.
My loads are 11.5 amps intermittent maximum, 6.1a. typical, and if alternator
quits, I could shut things off to get to about 3.3 amps for comfortable endurance
use. I see 13.1-13.3 volts on this bus during flight. I have had no issues
in 350 hours.
Since completing my RV in 2010, I have been absent from the aeroelectric list.
I have noticed that the Shottky diode is now recommended.
Did a search to attempt to 'catch up' with the discussion and have tentatively
concluded that this change would be purely optional, and not 'highly recommended'
for some electrical reason.
I'm on a weight reduction kick, so my only objective to change to the Shottky would
only be to eliminate the 1/2 lb. of the heatsink.
Bob, et al: I'm looking for some assurance. Have I missed something pertinent to
this decision or am I on track?
Roger
"For I know the plans I have for you," declares the Lord, "plans to prosper you
and not to harm you, plans to give you hope and a future." Jeremiah 29:11
Message 4
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| Subject: | Re: How to Toggle Speed Brakes with Momentary On Switch? |
A good example of where you can use a bi-stable switch is on NAV COM frequency
flip-flops.
Logic: If power is out to the radio, then the switch doesn't matter. If power is
restored, then no hazard occurs.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416904#416904
Message 5
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| Subject: | Re: Change to Shottky? |
Roger,=0A=0AThe advantage of Schottky diodes is that they have less voltage
drop than silicon diodes. Silicon is approx 0.7 volts and Schottky about 0
.5 volts. The advantage being that Schottkys dissipate a little less energy
.=0A=0AUsing your numbers for typical load:=0AExisting diode:=0AP = IE=0A
6 * .7 = 4.2W=0A=0ASchottky diode:=0A6 * .5 = 3.0W=0A=0AI agree w/ your
conclusion, probably not worth changing anything for a delta of 1.2W.=0A
=0A-Jeff=0A=0A=0A=0A________________________________=0A From: Roger Evenson
<revenson@comcast.net>=0ATo: AeroElectric-List@matronics.com =0ASent: Tues
day, January 14, 2014 7:19 AM=0ASubject: AeroElectric-List: Change to Shott
ky?=0A =0A=0A=0AI wired Z11 with the earlier recommended endurance bus diod
e w/15 watt heatsink.- My loads are 11.5 amps intermittent maximum, 6.1a.
typical, and if alternator quits, I could shut things off to get to about
3.3 amps for comfortable endurance use.- I see 13.1-13.3 volts on this bu
s during flight.- I have had no issues in 350 hours.=0A=0ASince completin
g my RV in 2010, I have been absent from the aeroelectric list.- I have n
oticed that the Shottky diode is now recommended.=0ADid a search to attempt
to 'catch up' with the discussion and have tentatively concluded that this
change would be purely optional, and not 'highly recommended' for some ele
ctrical reason.=0A=0AI'm on a weight reduction kick, so my only objective t
o change to the Shottky would only be to eliminate the 1/2 lb. of the heats
ink.=0A=0ABob, et al:- I'm looking for some assurance.- Have I missed s
omething pertinent to this decision or am I on track?=0A=0A=0ARoger=0A=0A
=0A"For I know the plans I have for you," declares the Lord, "plans to pros
per you and not to harm you, plans to give you hope and a future."- Jerem
=========================0A
Message 6
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| Subject: | Re: Change to Shottky? |
-At Bob's suggestion, I've been looking at double anode --single cathod
e arrangements in a TO-247 case, wired so that current goes through both di
odes.-- My average amperage will be 6-7-amps (12 to-14 total)-and
I can find packages that will have voltage drops of 0.3 volts or less.-
The tradeoff is higher leakage, but I don't see how a few tens of-mA will
cause problems.- With only 4 watts or so, Bob suggested using the alumin
um already behind the panel.- Even if you don't have enough sheet aluminu
m, there are light-weight heat sinks for the TO-247 package that only cost
a couple of bucks and weigh-an ounce or so.- The TO-247-does have to
be solder connected and mounted with an electrically resistive-pad, which
adds-little to cost or weight.=0A=0ATom=0A=0A=0A=0A=0A>_________________
_______________=0A> From: Jeff Luckey <jluckey@pacbell.net>=0A>To: "aeroele
ctric-list@matronics.com" <aeroelectric-list@matronics.com> =0A>Sent: Tuesd
ay, January 14, 2014 9:49 AM=0A>Subject: Re: AeroElectric-List: Change to S
hottky?=0A> =0A>=0A>=0A>Roger,=0A>=0A>=0A>The advantage of Schottky diodes
is that they have less voltage drop than silicon diodes. Silicon is approx
0.7 volts and Schottky about 0.5 volts. The advantage being that Schottkys
dissipate a little less energy.=0A>=0A>=0A>Using your numbers for typical
load:=0A>Existing diode:=0A>P = IE=0A>6 * .7 = 4.2W=0A>=0A>=0A>Schottky
diode:=0A>6 * .5 = 3.0W=0A>=0A>=0A>I agree w/ your conclusion, probably
not worth changing anything for a delta of 1.2W.=0A>=0A>=0A>-Jeff=0A>=0A>
=0A> =0A>=0A>________________________________=0A> From: Roger Evenson <reve
nson@comcast.net>=0A>To: AeroElectric-List@matronics.com =0A>Sent: Tuesday,
January 14, 2014 7:19 AM=0A>Subject: AeroElectric-List: Change to Shottky?
=0A> =0A>=0A>=0A>I wired Z11 with the earlier recommended endurance bus di
ode w/15 watt heatsink.- My loads are 11.5 amps intermittent maximum, 6.1
a. typical, and if alternator quits, I could shut things off to get to abou
t 3.3 amps for comfortable endurance use.- I see 13.1-13.3 volts on this
bus during flight.- I have had no issues in 350 hours.=0A>=0A>Since compl
eting my RV in 2010, I have been absent from the aeroelectric list.- I ha
ve noticed that the Shottky diode is now recommended.=0A>Did a search to at
tempt to 'catch up' with the discussion and have tentatively concluded that
this change would be purely optional, and not 'highly recommended' for som
e electrical reason.=0A>=0A>I'm on a weight=0A reduction kick, so my only o
bjective to change to the Shottky would only be to eliminate the 1/2 lb. of
the heatsink.=0A>=0A>Bob, et al:- I'm looking for some assurance.- Hav
e I missed something pertinent to this decision or am I on track?=0A>=0A>
=0A>Roger=0A>=0A>=0A>"For I know the plans I have for you," declares the Lo
rd, "plans to prosper you and not to harm you, plans to give you hope and a
-========================
=========== =0A>=0A>
Message 7
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Hi - I'm installing a Kannad Integra 406AF ELT with built in GPS. The cheapest
antenna for this ELT is the whip, which is what I bought with it. The blade/vane
for this unit are hundreds/thousands more expensive. But now I'm trying
to figure out where to put the whip! It's a monstrosity.
Aircraft is a Super Chipmunk which I'm totally rebuilding. (Google "Super Chipmunk
Restoration".) I successfully completed a new electrical system using the
Z-11 architecture and knowledge gained from the Aeroelectric Connection and this
list. (Thanks!!) The ELT is the last thing on the to-do list before I secure
all the wire bundles.
This is an unusual Chippy - it's single seat open cockpit, and I installed an 8
foot long turtleback/headrest to conceal a rollover bar behind the rear seat.
It's .025 alum, about a foot high/wide at the cockpit then tapering to about
4 inches at the fin. I'd like to mount the antenna 2 feet back on the top of
the main fuselage structure, so the rubber part is inside the turtleback, then
poke the steel whip out the top through a small hole/grommet. That approach
would be unobtrusive, avoid an ugly 2 foot tall antenna with fat black base,
and avoid beefing up the turtleback top to support it. My question: would the
ELT still be heard with the bottom 8 inches or so of base hidden under .025
alum?
Thanks!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416915#416915
Message 8
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Mark,
<< would the ELT still be heard with the bottom 8 inches or so of base
hidden under .025 alum? >>
Yes.
You are much more likely to not be heard by having the external part of the
whip sheared off in the crash.
The longer answer involves not only the shielding effect caused by the
aluminum but also the feed mismatch, both of which will reduce signal
output. But the application is so direct there is no doubt you could be
heard by a satellite. If you wish to be sure, build a mock up with foil
over cardboard and scrap tubing. See how it works with and without the
foil. Don't forget the rules about when and how to test ELTs.
Tom Kuffel
Message 9
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The Kannad whip antenna is base-loaded, so the ugly first 6" black base is
part of the radiating element that needs to be exposed. I'll be making an
angled mount with fibreglass fairing like a COM antenna for the underside of
my Rocket, since I also have a manual 406 GPS PLB. I figure any automatic
activation of the ELT will be because of a sudden stop, so I'll probably be
upside down about then. My life may depend on the automatic system pointing
skywards from the underbelly.
Kind regards, Stu
F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
www.teamrocketaircraft.com
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
msmeredith
Sent: Wednesday, January 15, 2014 2:04 PM
Subject: AeroElectric-List: ELT Antenna
--> <msmeredith@comcast.net>
Hi - I'm installing a Kannad Integra 406AF ELT with built in GPS. The
cheapest antenna for this ELT is the whip, which is what I bought with it.
The blade/vane for this unit are hundreds/thousands more expensive. But now
I'm trying to figure out where to put the whip! It's a monstrosity.
Aircraft is a Super Chipmunk which I'm totally rebuilding. (Google "Super
Chipmunk Restoration".) I successfully completed a new electrical system
using the Z-11 architecture and knowledge gained from the Aeroelectric
Connection and this list. (Thanks!!) The ELT is the last thing on the
to-do list before I secure all the wire bundles.
This is an unusual Chippy - it's single seat open cockpit, and I installed
an 8 foot long turtleback/headrest to conceal a rollover bar behind the rear
seat. It's .025 alum, about a foot high/wide at the cockpit then tapering
to about 4 inches at the fin. I'd like to mount the antenna 2 feet back on
the top of the main fuselage structure, so the rubber part is inside the
turtleback, then poke the steel whip out the top through a small
hole/grommet. That approach would be unobtrusive, avoid an ugly 2 foot tall
antenna with fat black base, and avoid beefing up the turtleback top to
support it. My question: would the ELT still be heard with the bottom 8
inches or so of base hidden under .025 alum?
Thanks!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416915#416915
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