 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
sshook(at)cox.net
Guest
|
 Posted: Tue Nov 20, 2007 9:44 am Post subject: Question about Relays/Switches |
 |
|
Morning All,
I am working on some of the electronics of our -7A slider and have a couple of questions…
Here are some details of our installation:
· I am going with a modified Z19RB electrical system and I am using some suggestions from Gary at Eggenfellner for wiring our E-Bus.
· We are using Honeywell AML34 lighted rockers and all the information I see is that they handle 15A – I know we will need some relays.
· One of those switches will be an On-Off-On for switching between Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the Primary Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto Zone for electrical equipment. What type of relays would I get? Are Bosch (insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
jonathan.cook(at)symech.c
Guest
|
| Posted: Tue Nov 20, 2007 10:46 am Post subject: Question about Relays/Switches |
|
|
Hello Scott,
I am also planning on using the Honeywell AML switches.
The 34 series will handle 15A, but only comes in ON-OFF.
To have the On-Off-On switch you would use a AML 24 series. (like AML24 F B C 2 CA 04) The AML 24 series can switch 5A which should be able fine for switching a relay.
Jonathan Cook
RV7
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Scott R. Shook
Sent: Tuesday, November 20, 2007 12:39 PM
To: aeroelectric-list(at)matronics.com
Subject: AeroElectric-List: Question about Relays/Switches
Morning All,
I am working on some of the electronics of our -7A slider and have a couple of questions…
Here are some details of our installation:
· I am going with a modified Z19RB electrical system and I am using some suggestions from Gary at Eggenfellner for wiring our E-Bus.
· We are using Honeywell AML34 lighted rockers and all the information I see is that they handle 15A – I know we will need some relays.
· One of those switches will be an On-Off-On for switching between Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the Primary Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto Zone for electrical equipment. What type of relays would I get? Are Bosch (insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved) | Quote: | | http://www.matronics.com/contribution |
012345678901234
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Tue Nov 20, 2007 11:42 am Post subject: Question about Relays/Switches |
|
|
At 10:39 AM 11/20/2007 -0700, you wrote:
| Quote: | Morning All,
I am working on some of the electronics of our -7A slider and have a
couple of questions&
Here are some details of our installation:
· I am going with a modified Z19RB electrical system and I am using
some suggestions from Gary at Eggenfellner for wiring our E-Bus.
· We are using Honeywell AML34 lighted rockers and all the
information I see is that they handle 15A I know we will need some relays.
· One of those switches will be an On-Off-On for switching between
Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two
different power sources and outputting to a single power source?
|
Why solid state? Your AML switch is mechanical,
why not drive a mechanical relay too?
| Quote: | Would I have to use two separate relays for switching between the Primary
Bus and Essential Bus?
|
Probably . . .
| Quote: | While I am using an auto conversion, I am not shopping the local Auto Zone
for electrical equipment. What type of relays would I get? Are Bosch
(insert Amperage) Solid State Relays suitable for our uses?
|
Where have you found a solid state relay by Bosch.
I've seen some Hella products. See:
http://tinyurl.com/yuvyt9
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
jonathan.cook(at)symech.c
Guest
|
| Posted: Tue Nov 20, 2007 11:48 am Post subject: Question about Relays/Switches |
|
|
Hello Scott,
I also wanted to Add that I and other have/are using AMP automotive fuses. One of the benefits is that you can use 1/4 “ fast on connectors. I plan on using AMP type fuses that have a tap with a hole so I can bolt these fuses to some structure in the fuselage. Dan Checkoway shows this on his site.
Dan Describes McMaster-carr relays 9672k12 http://www.rvproject.com/20030608.html http://www.mcmaster.com/
Dan Shows the relays http://www.rvproject.com/20030610.html
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jonathan B. Cook
Sent: Tuesday, November 20, 2007 1:46 PM
To: aeroelectric-list(at)matronics.com
Subject: RE: AeroElectric-List: Question about Relays/Switches
Hello Scott,
I am also planning on using the Honeywell AML switches.
The 34 series will handle 15A, but only comes in ON-OFF.
To have the On-Off-On switch you would use a AML 24 series. (like AML24 F B C 2 CA 04) The AML 24 series can switch 5A which should be able fine for switching a relay.
Jonathan Cook
RV7
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Scott R. Shook
Sent: Tuesday, November 20, 2007 12:39 PM
To: aeroelectric-list(at)matronics.com
Subject: AeroElectric-List: Question about Relays/Switches
Morning All,
I am working on some of the electronics of our -7A slider and have a couple of questions…
Here are some details of our installation:
· I am going with a modified Z19RB electrical system and I am using some suggestions from Gary at Eggenfellner for wiring our E-Bus.
· We are using Honeywell AML34 lighted rockers and all the information I see is that they handle 15A – I know we will need some relays.
· One of those switches will be an On-Off-On for switching between Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the Primary Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto Zone for electrical equipment. What type of relays would I get? Are Bosch (insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved) | Quote: | | http://www.matronics.com/contribution |
| Quote: | | http://www.matronics.com/Navigator?AeroElectric-List |
| Quote: | | http://forums.matronics.com |
01234567890123456
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Tue Nov 20, 2007 1:13 pm Post subject: Question about Relays/Switches |
|
|
At 02:44 PM 11/20/2007 -0500, you wrote:
| Quote: | Hello Scott,
I also wanted to Add that I and other have/are using AMP automotive fuses.
|
AMP automotive fuses? Did you mean Relays?
| Quote: | One of the benefits is that you can use 1/4 fast on connectors. I plan
on using AMP type fuses that have a tap with a hole so I can bolt these
fuses to some structure in the fuselage. Dan Checkoway shows this on his site.
Dan Describes McMaster-carr relays 9672k12
<http://www.rvproject.com/20030608.html>http://www.rvproject.com/20030608.html
http://www.mcmaster.com/
Dan Shows the relays
<http://www.rvproject.com/20030610.html>http://www.rvproject.com/20030610.html
|
These are plain vanilla electro-mechanical relays,
not solid state.
The part number Dan cites (9672K12)
is no longer available. McMaster
suggests a 9672K32 (or weatherproof
9672K44) which you can see at:
http://www.aeroelectric.com/Mfgr_Data/Misc/McMaster_p865.pdf
It takes two pass transistors in a solid
state relay to effect double pole, double
throw functionality. If there's much interest
in such a device, we could look into supplying
it . . . probably in the same package as
http://aeroelectric.com/Catalog/AEC/9030/9030.jpg
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
sshook(at)cox.net
Guest
|
| Posted: Tue Nov 20, 2007 3:02 pm Post subject: Question about Relays/Switches |
|
|
Bob,
Thank you much for the information. Those look like the regular vanilla
automotive relays that I have used for years in cars.
Are those suitable for our applications? I am just not certain I want to
entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to
a $9 relay.
If that's the case, I could use a SPDT continuous duty relay (like a Marine
application) found here -
http://www.ebasicpower.com/pc/ARCR038/ALLRELAYS/Relay%2C+12V%2C+85+Amp%2C+S.
P.D.T. to power my E-Bus from my Main Battery.
I could even get radical and have the Main Battery power my E-Bus when the
coil is energized and have it switch to my Aux Battery when coil is not
energized. Since there is already a SPST Continuous Duty Relay upstream of
both my main battery and aux battery, powering down the plane shouldn't be a
problem.
Thoughts?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Wed Nov 21, 2007 4:02 pm Post subject: Question about Relays/Switches |
|
|
At 03:58 PM 11/20/2007 -0700, you wrote:
| Quote: |
Bob,
Thank you much for the information. Those look like the regular vanilla
automotive relays that I have used for years in cars.
Are those suitable for our applications? I am just not certain I want to
entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to
a $9 relay.
|
Sure, why not? What can a relay DO that puts the
equipment at risk? In this case, it's used in but
on of two power paths which should share no common
hardware. So if one path is down it is (1) preflight
detectable, (2) does not cause an immediate hazard
to flight for in flight failure.
How big are the loads on your e-bus?
| Quote: | I could even get radical and have the Main Battery power my E-Bus when the
coil is energized and have it switch to my Aux Battery when coil is not
energized. Since there is already a SPST Continuous Duty Relay upstream of
both my main battery and aux battery, powering down the plane shouldn't be a
problem.
|
Methinks thou worriest too much. First, assume
that ANY piece of hardware you incorporate into
your system can and at some time will fail in
flight. The proceed to architecture your system
with the following in mind:
Nuckolls' first law of airplane systems design sez: "Things
break"
The second: "Systems shall be designed so that when things
break, no immediate hazard is created."
The third: "Things needed for comfortable termination of
flight require backup or special consideration to insure
operation and availability"
The forth: "Upgrading the quality, reliability, longevity, or
capability of a part shall be because you're tired of replacing
it or want some new feature, not because it damned near got
you killed."
If you've done your homework, then no single
failure of a component will put the flight
at risk for unhappy termination. The thought
process goes toward designing for failure
tolerance as opposed to seeking components
that will never fail.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
echristley(at)nc.rr.com
Guest
|
| Posted: Thu Nov 22, 2007 7:52 am Post subject: Question about Relays/Switches |
|
|
Scott R. Shook wrote:
| Quote: | Are those suitable for our applications? I am just not certain I want to
entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to
a $9 relay.
I'm trusting many thousands of dollars and six years of building time to
|
several pieces of 3/8" steel tube that cost only a few dollars each.
Your electronics stack if full of components that will go belly up if it
looses a $.03 resister or diode. What happens if a $2 valve stem breaks?
Step back a moment and think about it. Eliminating a component from
consideration because it isn't expensive enough is just silly. Is the
thing engineered properly to handle the intended job or not. If the
relay works flawlessly in an automobile, it will work just as well in
reasonably similar conditions (ie, an airplane).
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)cox.net
Guest
|
| Posted: Thu Nov 22, 2007 6:38 pm Post subject: Question about Relays/Switches |
|
|
At 10:49 AM 11/22/2007 -0500, you wrote:
| Quote: |
<echristley(at)nc.rr.com>
Scott R. Shook wrote:
>Are those suitable for our applications? I am just not certain I want to
>entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to
>a $9 relay.
>
I'm trusting many thousands of dollars and six years of building time to
several pieces of 3/8" steel tube that cost only a few dollars each.
Your electronics stack if full of components that will go belly up if it
looses a $.03 resister or diode. What happens if a $2 valve stem breaks?
Step back a moment and think about it. Eliminating a component from
consideration because it isn't expensive enough is just silly. Is the
thing engineered properly to handle the intended job or not. If the relay
works flawlessly in an automobile, it will work just as well in reasonably
similar conditions (ie, an airplane).
|
I've spent most of a career associated with and often
directly with a process called failure mode effects analysis
or FMEA for short. The process calls for studying a
system schematic and going through it part by part deducing
the effects of any expected failure. For example, resistors
may go open (usually because of bad connection or physical
damage) but they don't go shorted. They also don't change
value in profound ways. They may drift out of precise calibration
but a 47K resistor doesn't suddenly become a 33K resistor.
This is the process that must be conducted to determine
how any circuit (discrete components or integrated circuits)
to decide what the ramifications are for any probable
failure mode.
Once those modes are deduced, then depending on hazard
levels for those failures, a statistical study for
failures/flight hour may be conducted to see what
measures should be put into place to (1) reduce
risk to airframe and occupants and/or (2) reduce
risk cost of ownership.
In the case of a relay used to handle the e-bus
alternate feed, yes . . . relays are among the
LEAST reliable devices you can put into a system.
This is why I expressed a good bit of concern for
this electrically dependent engine installation
and the numbers of relays incorporated. See:
http://www.aeroelectric.com/Pictures/Misc/Too_Many_Relays.jpg
This installation was in serious need of
some re-design for simplification.
Having said that, modern automotive relays
are exceedingly robust and seldom troublesome
in our cars. So . . .
The question to be asked and answered in this
conversation is, "Does failure of a plain-
vanilla automotive relay pose risk of hazard
for any given flight?" Given that we're
talking about a failure tolerant design, the
answer should be "no". Indeed, the e-bus is
fitted with two, independent power sources and
routes. Further, the e-bus should drive only
those devices needed for minimum energy sustenance
of devices needed for en-route operations. If
one of those systems is necessary for comfortable
termination of flight, then a backup for that
system should be installed . . . and wired to
the main bus.
The point here is that architecture and parts
selection should be driven more by the big picture
for failure modes and propose missions for the
aircraft. The perceived or real "quality" of
a device should be more of a cost of ownership issue
than a safety issue.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
