Today's Message Index:
----------------------
1. 05:52 AM - DO-160 issues . . . (Robert L. Nuckolls, III)
2. 06:10 AM - Re: Split master switch (Robert L. Nuckolls, III)
3. 08:01 AM - Re: ACS switch wiring with Rotax 912S (Robert L. Nuckolls, III)
4. 08:18 AM - Watsonville (Ron Patterson)
5. 08:26 AM - Roy's 40A alternator installation on the Rotax 912 (Robert L. Nuckolls, III)
6. 09:30 AM - Lighted, engraved rocker switches (Scott Diffenbaugh)
7. 09:30 AM - SD-8 low voltage warning light (Scott Diffenbaugh)
8. 09:30 AM - Autoswitching dual alternators (Scott Diffenbaugh)
9. 09:30 AM - GPSpecial (Fergus Kyle)
10. 09:58 AM - Re: Lighted, engraved rocker switches (Ralph E. Capen)
11. 10:22 AM - Re: Lighted, engraved rocker switches (Scot Stambaugh)
12. 11:36 AM - Re: Autoswitching dual alternators (Robert L. Nuckolls, III)
13. 11:41 AM - Re: Lighted, engraved rocker switches (Brett Ferrell)
14. 11:45 AM - Re: SD-8 low voltage warning light (Robert L. Nuckolls, III)
15. 11:57 AM - Re: Watsonville (Robert L. Nuckolls, III)
16. 12:06 PM - Re: SD-8 low voltage warning light (Matt Prather)
17. 12:24 PM - Re: Autoswitching dual alternators (Matt Prather)
18. 01:10 PM - SD-8 preflight check (Ross Mickey)
19. 05:38 PM - Picture of headset jacks (Jeffrey W. Skiba)
20. 06:40 PM - Re: Picture of headset jacks ()
21. 06:49 PM - Voltage drop on contactors? (Robert L. Nuckolls, III)
22. 09:05 PM - Re: Picture of headset jacks (Jeffrey W. Skiba)
23. 09:19 PM - Re: Re: fuses vs. CBs (Chad Robinson)
24. 10:31 PM - Re: Picture of headset jacks (Dan Checkoway)
25. 11:25 PM - Re: ACS switch wiring with Rotax 912S (Alfred Buess)
Message 1
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | DO-160 issues . . . |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:16 PM 11/10/2003 -0600, you wrote:
>I have an Ultra model from Stratomaster It is installed in a Sonex and
>there have been 2 failures of the system that we know of. It appears that
>the spikes may be causing the system to fail. The product is made in South
>Africa and the company is suggesting that a capacitor across the power
>terminals. The other potential failure mode might be the fact that the RPM
>is being picked up off one of the leads that comes from the alternator. Any
>suggestions or guidance would be greatly appreciated.
>
>Warmest Regards
>John Davis
>Crossville, TN
>Sonex 523
It's a sad fact that many companies produce products
that are not able "to live in the real world". Some of
these products are even blessed with government holy-water.
They're accurately touted as the "latest and greatest advancements for
some fraction of aviation while at the same time, they
step backwards years, even decades in the implementation
of simple ideas that are the foundation for success in
the products they're claiming to promote!
If the manufacturer of any product suggests that an airplane's
electrical system is inherently "tainted" and
offers any sort of Band-Aid to offset the shortfall, this
only means that they've properly identified a shortcoming
in their product. Their hope is to use the right weasel-
words to convince you that YOU need to fix YOUR electrical
system if you wish to enjoy the boundless benefits for
having chosen their product.
It's your choice as a consumer to decide to (1) go the
extra mile to accommodate their short-sighted design
or (2) choose an alternative product wherein the
designers did their homework. If the manufacturer
of the product you're struggling with suggests adding
a capacitor to your electrical system, you can
give it a try. Of course, they could add the capacitor
to their accessory and save you LOTS of trouble.
>PS. I have ordered from the company and I have used a great deal of your
>information. Thank you so much for a Great WEB site.
Thank you for the kind words sir. I'm pleased that you
find the work so useful.
Bob . . .
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 |
|
| Subject: | Re: Split master switch |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:45 AM 11/9/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Building an RV7A electrical system utilizing AEC's Z-13 design. The bible
>notes there is not a need for a Cessna split type master anymore, & Z-13
>shows a dual pole single throw switch in its place. In addition, one of
>B&C's schematics on their website contains the note: "IMPORTANT -BATTERY
>CONTACTOR AND ALTERNATOR SHOULD COME ON AND OFF TOGETHER".
The simple two-pole, on-off switch can be used to simultaneously
control battery master and alternator field such that the alternator
is NOT allowed to be ON when the battery is OFF.
> During a main
>alt failure, isn't there a need to be able to turn on the battery contactor
>(while leaving the failed alt field switch off) to activate the main bus for
>flaps, landing lights, etc?
Yes, if you use the simple 2-3 ON-OFF switch -AND- crowbar ov protection
there will be a breaker that can be pulled to disable the alternator
for rare instances where the alternator must be manually disabled in
flight and the more common instances where battery only ground
maintenance operations are less stressful on the battery if the breaker
is pulled.
> To further complicate the issue, the below
>thread is now running on the matronics RV list where a guy is blowing his
>alt field fuse unless he leaves the alt field switch off during start. Can
>anyone educate me in this area?
> > Just recently my alternator has been acting up.
> > Problem: I have vans 35 amp alternator and a cessna style master switch. I
>have been flying my RV with setup for 155 hours before the problem occurred.
> > With both switches of the master on, I engage the starter and the plane
>starts, the alt. field fuse blows. If I turn the alt. switch off and start
>the plane then turn the alt. switch of the master on, everything is ok.
> > What is causing my fuse to blow?
If he has a crowbar ov protection system, there should be no
fuses involved to be blown. He has neglected to follow the diagrams
where circuit protection upstream of a crowbar ov module is ALWAYS
depicted as a breaker.
> > Thanks
> > John Danielson
> > Hi John,
>I don't know what is causing the fuse to blow, but if you have the Cessna
>Split Master switch I read in Light Plane Maintenance that it is preferable
>to start the engine with the Alternator Field "OFF" then once the engine
>starts turn the Alternator Field "ON". The reason for this was that it takes
>2 amps off the battery power capacity to provide the field with a charge.
>This power is not used to start the engine and it does not contribute to
>charging the battery until the engine is turning faster.
This was conventional wisdom of 1950 but with the cranking
ability of the modern RG battery being what it is, the notion
that one's engine will start better by relieving the battery
of perhaps 2-3% of total cranking load doesn't make sense.
> In my -8 I have the
>split switch and I start it with the battery only and then switch on the
>Alternator Field. This also allows me to check the battery voltage and
>verify that the Alternator kicks in by watching the Volts gauge. So what I'm
>saying is that I believe it is perfectly acceptable to start with the Alt
>Field OFF then turn it on when the engines running.
Sure doesn't hurt and probably doesn't help either.
>Good Luck- I would definitely find the cause of the fuse tripping though.
>Ed Perry
I could go into a discussion of trouble analysis and mitigation
for you to relay to the RV-List . . . but I think it wiser to
suggest that the writer be urged to contact the manufacturer and/or
designer of a product that's giving him problems instead of throwing
the question out onto a group that specializes in other issues.
I'm presuming that he's having problems with an ov module he built
or purchased from me or B&C. The AeroElectric-List is just a
sign-up away on the same server as the RV-List. I used to
subscribe to a dozen list servers and have to sort through
200-300 pieces of e-mail a day looking for electrical/avionics
systems issues. It simply got to be too much effort and served
only the folks on lists I subscribed to. Please encourage folks
on the various airframe lists to ALSO participate on the
AeroElectric-List where their electrical systems issues are most
likely to be dealt with quickly and to the benefit of more
builders.
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 |
|
| Subject: | Re: ACS switch wiring with Rotax 912S |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:16 PM 11/11/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: Joa Harrison
><flyasuperseven@yahoo.com>
>
>Does anybody know if you need to jumper terminal 1 and/or use the LR & BO
>terminals with the Rotax 912S ignition system and the ACS A-510-2 switch?
>
>Thanks.
>
>Joa
Wire per Figure Z-17 of
http://www.aeroelectric.com/articles/Rev10/z10.pdf
Bob . . .
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 |
|
--> AeroElectric-List message posted by: Ron Patterson <scc_ron@yahoo.com>
Hi all,
I was an attendee of Bob's seminar last weekend on wiring your aircraft, and I
just wanted to let those on the list know that if you haven't taken this seminar...sign
up ASAP. Bob is hands down the aviation wiring Guru. He imparts his
knowledge with a passion that only comes from someone who does what he does because
he loves doing it!
The cost is more than fair and you will save 3-10 times the $150 you spend by not
buying things you don't need, or having to 'start over' after you realize you
haven't done your wiring job correctly (ie: simply/easlily).
Ron Patterson
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 |
|
| Subject: | Roy's 40A alternator installation on the Rotax 912 |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>The Rotax 912ULS in my plane has the standard 18A alternator and an
>optional 40A ND alternator driven by belt from the front of the engine.
>Each alternator has Bobs OV protections. Im using a single 18AH RG battery.
>
>Regards,
>
>Roy
Roy, I think I knew at one time but I've lost information on your
40A alternator installation on the Rotax. Do you have pictures
you could send me on this installation. Also, is attach hardware
something you had to build or is it offered by a manufacturer?
Bob . . .
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 |
|
| Subject: | Lighted, engraved rocker switches |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
Can anyone point me to a good source for high quality engraved lighted
rocker switches?
If I change my mind and end up going with toggle switches, what is the best
way to light them. (All of my instruments & avionics will be internally
lighted)
Scott Diffenbaugh
diff@foothill.net
Message 7
| 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: | SD-8 low voltage warning light |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
Just curious why Z-13 doesn't show a low voltage warning light for the SD-8,
but on B&C's website one of their SD-8 installation drawings shows it and
another does not. After reviewing 4 year's worth of web discussion on
battery/alternator monitoring, it seems that the low voltage light is the
most important warning of a problem for the main alternator. Wouldn't this
also be the case for the backup alternator? Thank you.
Scott Diffenbaugh
diff@foothill.net
Message 8
| 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: | Autoswitching dual alternators |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
I have just learned that it is not a good idea to have dual alternators
running at the same time for many reasons. How about using autoswitching
mentioned in the AEC as "...the easiest way to add a second engine driven
power source to an existing design." Since it doesn't appear to be used in
Z-12 or Z-13, can someone explain why not use it? Thank you.
Scott Diffenbaugh
diff@foothill.net
Message 9
| 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 |
|
<aeroelectric-list@matronics.com>
--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
There you go............
Jim Weir in the latest (must be DEC03) issue, tried out an AOL CD-ROM disc
as a groundplane for his GPS, on his hightech garbage-can antenna test
range, and found a barely measureable difference from carefully-fashioned
aluminum sheet.
I consider my model Europa to be high-tech since it will incorporate 3
AOL discs - one under the fuel selector handle, one under the GPS antenna
and one under the TXR stub - for now anyway.
Cheers, Ferg
Europa Mono #A064
Message 10
| 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: | Re: Lighted, engraved rocker switches |
--> AeroElectric-List message posted by: "Ralph E. Capen" <recapen@earthlink.net>
I got mine from Electronic Technologies... www.electronictechnologies.net
etech@ucnsb.net and had the engraving done up in New England.
Also you can contact them through
http://groups.yahoo.com/group/ExperimentalAvionics/
----- Original Message -----
From: "Scott Diffenbaugh" <diff@foothill.net>
Subject: AeroElectric-List: Lighted, engraved rocker switches
> --> AeroElectric-List message posted by: "Scott Diffenbaugh"
<diff@foothill.net>
>
> Can anyone point me to a good source for high quality engraved lighted
> rocker switches?
> If I change my mind and end up going with toggle switches, what is the
best
> way to light them. (All of my instruments & avionics will be internally
> lighted)
>
> Scott Diffenbaugh
> diff@foothill.net
>
>
Message 11
| 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: | Re: Lighted, engraved rocker switches |
--> AeroElectric-List message posted by: Scot Stambaugh <sstambaugh@qualcomm.com>
If you go with the toggles you might consider this stuff:
http://sptpanel.com/glow_strips.htm
I installed it in my Rocket and like it a lot because it is
dimmable. Attached is a picture of my cockpit with the lights out and the
panels lit using the glow strips.
scot
At 09:29 AM 11/12/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Can anyone point me to a good source for high quality engraved lighted
>rocker switches?
>If I change my mind and end up going with toggle switches, what is the best
>way to light them. (All of my instruments & avionics will be internally
>lighted)
>
>Scott Diffenbaugh
>diff@foothill.net
>
>
Message 12
| 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: | Re: Autoswitching dual alternators |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:29 AM 11/12/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>I have just learned that it is not a good idea to have dual alternators
>running at the same time for many reasons. How about using autoswitching
>mentioned in the AEC as "...the easiest way to add a second engine driven
>power source to an existing design." Since it doesn't appear to be used in
>Z-12 or Z-13, can someone explain why not use it? Thank you.
You lost me . . . Z-12 IS an autoswitched design. One simply
ties both main and aux alternators to the bus and sets
the aux alternator about a volt below the main alternator.
You run both alternators ON all the time. The aux alternator
regulator sees a "too high" bus and simply relaxes. If the
main alternator fails, bus voltage sags and the aux alternator
comes alive to pick up the load.
The SB-1 regulator was specifically designed for this service
in that what WAS a "low volts" warning light HAS BEEN MODIFIED
to measure aux alternator b-lead current with a hall-effect
current sensor. When the main alternator goes down, current draw
from the aux alternator jumps up. If the current exceeds 20A,
the light flashes. When you switch off enough things to bring
the current below 20A, the light switches to steady operation.
This is the system STC'ed on many certified aircraft by B&C
and is a reasonable alternative to the major changes necessary
to implement Z-14 in a certified ship. I don't recommend
it for new design but that doesn't mean it isn't a perfectly
acceptable alternative to traditional systems flying in
virtually all certified ships. If this architecture floats
your boat then drive on . . . it's still light-years ahead
of most hardware flying today.
Bob . . .
Message 13
| 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: | Re: Lighted, engraved rocker switches |
--> AeroElectric-List message posted by: Brett Ferrell <bferrell@123mail.net>
They can also do very nice custom lighted legend sheets. They did mine for my
Veloctiy XL's overhead switch panel:
http://www.velocityxl.com/Electrical.htm#Chapter 13.3.4 - Switches and Circuit Protection
Brett
Quoting Scot Stambaugh <sstambaugh@qualcomm.com>:
> --> AeroElectric-List message posted by: Scot
> Stambaugh <sstambaugh@qualcomm.com>
>
> If you go with the toggles you might consider this
> stuff:
> http://sptpanel.com/glow_strips.htm
> I installed it in my Rocket and like it a lot because
> it is
> dimmable. Attached is a picture of my cockpit with
> the lights out and the
> panels lit using the glow strips.
>
> scot
>
>
> At 09:29 AM 11/12/2003 -0800, you wrote:
> >--> AeroElectric-List message posted by: "Scott
> Diffenbaugh"
> ><diff@foothill.net>
> >
> >Can anyone point me to a good source for high quality
> engraved lighted
> >rocker switches?
> >If I change my mind and end up going with toggle
> switches, what is the best
> >way to light them. (All of my instruments & avionics
> will be internally
> >lighted)
> >
> >Scott Diffenbaugh
> >diff@foothill.net
> >
> >
>
>
> on the
> this
> generous
> Contributions
> any other
> Forums.
> http://www.matronics.com/subscription
> http://www.matronics.com/FAQ/AeroElectric-List.htm
> http://www.matronics.com/photoshare
> http://www.matronics.com/emaillists
>
>
>
>
--
Visit us at www.velocityxl.com
44VF Velocity XL/FG
I68 Cincinnati, OH
Message 14
| 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: | Re: SD-8 low voltage warning light |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:29 AM 11/12/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Just curious why Z-13 doesn't show a low voltage warning light for the SD-8,
>but on B&C's website one of their SD-8 installation drawings shows it and
>another does not. After reviewing 4 year's worth of web discussion on
>battery/alternator monitoring, it seems that the low voltage light is the
>most important warning of a problem for the main alternator. Wouldn't this
>also be the case for the backup alternator? Thank you.
Keep in mind that the power distribution diagrams illustrate
implementation of ideas for architecture . . . they are not
intended to put either upper or lower bounds on features one
might choose to include. Figure Z-13 shows low voltage warning
in that this feature is part of the LR-3 design. If the main
alternator is down, and assuming you've done a load analysis
for aux-alternator-only operations, it's reasonable to assume
that you're not going to be overloading the SD-8 and bus voltage
will be fine. If your design includes a voltmeter, I'd run it
from the endurance bus. If you don't plan a voltmeter and would
like to add low voltage monitoring, it's certainly easy to do
with the ACE9005 LV Warning at:
http://www.aeroelectric.com/Catalog/AEC/9005/9005.html
or can built it as shown at
http://www.aeroelectric.com/articles/lvwarn/9021-620.pdf
and
http://www.aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html
Just because a Z-figure does or does-not show a particular
feature doesn't mean it isn't something that should be considered
and added or deleted based on your personal understanding
and requirements for system functionality.
Bob . . .
Message 15
| 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 |
|
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:18 AM 11/12/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: Ron Patterson <scc_ron@yahoo.com>
>
>Hi all,
>
>I was an attendee of Bob's seminar last weekend on wiring your aircraft,
>and I just wanted to let those on the list know that if you haven't taken
>this seminar...sign up ASAP. Bob is hands down the aviation wiring Guru.
>He imparts his knowledge with a passion that only comes from someone who
>does what he does because he loves doing it!
>
>The cost is more than fair and you will save 3-10 times the $150 you spend
>by not buying things you don't need, or having to 'start over' after you
>realize you haven't done your wiring job correctly (ie: simply/easlily)
>
>Ron Patterson
Thank you for the kind words Ron. We appreciate your
participation and support both as a member of the
OBAM aircraft community and as the select group of
builders who are helping drive the art and technology
forward.
I had lunch with some suppliers to Raytheon who
had sad tales to tell about how regulatory and
systems approaches to management have multiplied the $time$
it takes to arrive at the elegant solution. This assumes that
the elegant solutions can be found . . . when you're out
of budget, you go to production irrespective of the
warts that may still exist with the design.
If there is any bright star on the horizon for general
aviation, it's glowing in the basements and garages of
builders everywhere.
Bob . . .
Message 16
| 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: | Re: SD-8 low voltage warning light |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Hi Scott,
I have a few thoughts regarding this topic, a couple of which bring up
questions of my own. The first is that the drawings in the Z appendix
are intended as a starting place so that we may better understand how
to design and implement aircraft electrical systems. It is up to us
to decide how to apply the concepts we learn from the Aeroelectric
Connection Book (and the Z appendiz in particular) when working on our
own airplanes. For a given airplane, it is likely that none of the
circuits shown in the Z appendiz will work exactly as drawn.
My second thought is that a standard low voltage circuit won't
work in the Z-13 design. As long as at least one of the alternators
is on line, and keeping up with the demands of the system, the
respective bus voltage will remain above the low voltage threshold.
I would imagine that the circuits where a low voltage warning has
been included with the SD8 are where that is the sole alternator
in the system. Or, where the SD8 is used in a split bus architecture.
The Z-13 circuit does give a means for indicating Alternator load
on the SD8.
It is possible test the SD8 when at runup or in flight. You can
disable the main Alt, and make sure that the load meter on the SD8
gives a positive reading, indicating that it is charging. You will
have to play with bus loads to see how much its putting out.
To get a warning of a failed backup alternator, its useful to consider
what the fail modes of the SD8 are, and how they might effect overall
system performance. The 3 modes that I can think of are, that the
regulator goes into runaway mode (overvoltage), turns off (disconnect),
or shorts to ground.
If the regulator goes into runaway the crowbar module will trip, which
will quickly open the SD8's feed, disconnecting it from the main bus.
At least, I think this is how it will work... My question here is,
what happens if the overall system loads are more than the total
output of the SD8?? I wonder this because I think what will happen is
that the main Alt's regulator will sense the rising bus voltage, and
reduce the main Alt's output, keeping bus voltage stable. I guess
this is okay, because it probably won't hurt the SD8 to be max'ed out
(since its PM, its always max'ed out). Then, if you flip some
switches in the cockpit which reduce system loads below the full
output of the SD8, the bus voltage will rise high enough to trip the
crowbar module, disconnecting the SD8. Still, no warning, as the
circuit is drawn. Kind of annoying behavior because you don't know
exactly when the SD8 started misbehaving, but probably still okay.
The next fail mode is a disconnect. If the fail is an open circuit, it
may be tough to detect without shutting off the main alt. Have to think
on this one a bit.
Finally, if the SD8 shorts to ground, it will take out the fuse link
connecting it to the battery. This ends up like all of the other fail
modes... The SD8 gets disconnected from the electrical system.
All of these are fairly non-events. If you have a fresh battery, and it
was sized correctly to start with, your battery will last longer than
the fuel supply. Worst case scenario, you take off with 2 operating alts,
the little one fails early (and you don't know about it), the big one
fails shortly there after, and you run on the essential bus intil you
get where you were planning to go. The chances of dual alternator fails
is probably similar to 2 mag fails in the same flight.
One question that I have is that in examining this schematic, it looks
like both alt's regulators are tied to the same bus. I thought this was
to be avoided, as neither will have exactly the same setpoint. However,
as described above, I suspect that if the PM's output voltage is less than
the main's, it will just be along for the ride, sharing none of the load
unless the main fails. If the PM's output voltage is higher than the
main's, the main never sees more than total bus loads minus the full
rated output of the the PM. Probably still okay. Maybe the rule is that
if full bus loads are less than the rating of your biggest alt, you can
tie their outputs together. How about it Bob?
Sorry for the length....
Regards,
Matt Prather
N34RD
> --> AeroElectric-List message posted by: "Scott Diffenbaugh"
> <diff@foothill.net>
>
> Just curious why Z-13 doesn't show a low voltage warning light for the
> SD-8, but on B&C's website one of their SD-8 installation drawings shows
> it and another does not. After reviewing 4 year's worth of web
> discussion on battery/alternator monitoring, it seems that the low
> voltage light is the most important warning of a problem for the main
> alternator. Wouldn't this also be the case for the backup alternator?
> Thank you.
>
> Scott Diffenbaugh
> diff@foothill.net
>
Message 17
| 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: | Re: Autoswitching dual alternators |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Thanks Bob... This message answers the questions I asked in another
message about bus sharing.
Matt-
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
>
> At 09:29 AM 11/12/2003 -0800, you wrote:
>>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
>><diff@foothill.net>
>>
>>I have just learned that it is not a good idea to have dual alternators
>> running at the same time for many reasons. How about using
>> autoswitching mentioned in the AEC as "...the easiest way to add a
>> second engine driven power source to an existing design." Since it
>> doesn't appear to be used in Z-12 or Z-13, can someone explain why not
>> use it? Thank you.
>
> You lost me . . . Z-12 IS an autoswitched design. One simply
> ties both main and aux alternators to the bus and sets
> the aux alternator about a volt below the main alternator.
> You run both alternators ON all the time. The aux alternator
> regulator sees a "too high" bus and simply relaxes. If the
> main alternator fails, bus voltage sags and the aux alternator
> comes alive to pick up the load.
>
> The SB-1 regulator was specifically designed for this service
> in that what WAS a "low volts" warning light HAS BEEN MODIFIED
> to measure aux alternator b-lead current with a hall-effect
> current sensor. When the main alternator goes down, current draw from
> the aux alternator jumps up. If the current exceeds 20A,
> the light flashes. When you switch off enough things to bring
> the current below 20A, the light switches to steady operation.
>
> This is the system STC'ed on many certified aircraft by B&C
snip
> of most hardware flying today.
>
> Bob . . .
>
Message 18
| 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: | SD-8 preflight check |
--> AeroElectric-List message posted by: "Ross Mickey" <rmickey@ix.netcom.com>
I wired my RV6A using Z-13. I have one of Bob's loadmeter/voltmeters that
is not operating on the loadmeter side but is working on the voltmeter side.
Doing my pre-flight tests, turning on the main alternator, the voltmeter
shows a jump from battery voltage to 14+ volts. When I shut down the main
alternator and main bus and turn on the SD-8, I get no movement above
battery voltage. Is this normal? If so, how do I check to see if the SD-8
is working in pre-flight? Some of my instruments are hooked directly to the
essential bus (no intermediate switch) so I can't turn everything off so
there is no load on the battery.
Ross Mickey
N9PT
Message 19
| 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: | Picture of headset jacks |
--> AeroElectric-List message posted by: "Jeffrey W. Skiba" <jskiba@icosa.net>
I lost my picture I printed,
A while back I saw on the list a very nice picture with descriptions of what
was what on different types of headset and mic jacks. I tried a search of
the list with no luck any body help out ?
Thanks
Jeff
Message 20
| 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: | Re: Picture of headset jacks |
--> AeroElectric-List message posted by: <315@cox.net>
Jeff,
Check out the link below:
http://www.aeroelectric.com/articles/micjack/micjack.html
Your Fellow builder,
Ned
----- Original Message -----
From: "Jeffrey W. Skiba" <jskiba@icosa.net>
Subject: AeroElectric-List: Picture of headset jacks
> --> AeroElectric-List message posted by: "Jeffrey W. Skiba"
<jskiba@icosa.net>
>
>
> I lost my picture I printed,
> A while back I saw on the list a very nice picture with descriptions of
what
> was what on different types of headset and mic jacks. I tried a search of
> the list with no luck any body help out ?
>
> Thanks
> Jeff
>
>
Message 21
| 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: | Voltage drop on contactors? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>Comments/Questions: Voltage drop across Master Relay. I am building a F1
>Rocket. The battery is back in the tail. The kit manufacturer calls for
>the master relay back by the battery and a starter relay up in the engine
>area.On a cold day and the voltage drop across both relays could cause for
>less power to the starter. Would I be better off to put the starter relay
>back by the battery and use a smaller relay and smaller wire to the
>instrument panel? Your comments would be appriecated.
Use 2AWG wire and mount contactors in the usual places,
battery contactor right next to battery and intermittent
duty starter contactor on firewall. Voltage drop on the
wire is more significant than the contactors . . . this
is why 2AWG is recommended for all aircraft with rear
mounted battery. Of course, an RG battery is recommended
as well.
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 22
| 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: | Picture of headset jacks |
--> AeroElectric-List message posted by: "Jeffrey W. Skiba" <jskiba@icosa.net>
That helps but the one I was thinking of was almost a sketch of a jack and I
thought it was a stereo headphone jack.
Thanks in advance
Jeff
Check out the link below:
http://www.aeroelectric.com/articles/micjack/micjack.html
Message 23
| 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: | Re: fuses vs. CBs |
--> AeroElectric-List message posted by: Chad Robinson <crobinson@rfgonline.com>
> Why would you want to add so much $time$ to a product that
> has about one chance in 1000 of ever doing something useful?
>
> Once you're past the development phase of your design and all
> construction faults and nuisance trips are fixed, it's quite
> likely that your airplane will run a lifetime and never open
> a fuse.
Uhhhh, I don't. I asked for one pre-made. I'm asking for a fuse block
that has these suckers built in. If you read my original message I said
I didn't want to be the one doing this. I agree it's a waste of time,
and fuses with LEDs built in are overpriced and a waste of money. =)
I love playing Devil's Advocate, so I'll bite. How about this for an
argument? It's nice information to have when your engine starts cutting
out on your third test flight that you can glance down and see your fuel
pump (EFI here) has blown a fuse, perhaps because you DIDN'T fasten
things down as well as you thought and a wire abraded and shorted out.
You sure as heck aren't going to reach down and try to put in a new fuse
- it blew for a reason. But you can also avoid wasting time on trying an
engine restart, which reduces your workload somewhat. As long as you
aren't overloading the pilot with information (and you have to really
LOOK to get this bit) having more information available is often nice.
In point of fact I don't actually want them but when curiosity gets
ahold of me I like to track things down. I don't know what the weather's
like by you, but it's 15 degrees outside here tonight, so no plane
building for me (unheated shop). In the winter, research is all I can do.
Regards,
Chad
Message 24
| 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: | Re: Picture of headset jacks |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
Might this be the one?
http://www.rvproject.com/images/jack_wiring.jpg
)_( Dan
RV-7 N714D
http://www.rvproject.com
----- Original Message -----
From: "Jeffrey W. Skiba" <jskiba@icosa.net>
Subject: RE: AeroElectric-List: Picture of headset jacks
> --> AeroElectric-List message posted by: "Jeffrey W. Skiba"
<jskiba@icosa.net>
>
> That helps but the one I was thinking of was almost a sketch of a jack and
I
> thought it was a stereo headphone jack.
>
> Thanks in advance
> Jeff
>
> Check out the link below:
>
> http://www.aeroelectric.com/articles/micjack/micjack.html
>
>
Message 25
| 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: | Re: ACS switch wiring with Rotax 912S |
--> AeroElectric-List message posted by: "Alfred Buess" <Alfred.Buess@shl.bfh.ch>
Bob,
Z-17 shows no wire between GRD and the panel ground block . Is the switch only
grounded by the wire shields at the ignition terminal points? Would a separate
ground wire from the switch to the ground block create a groud loop?
Alfred
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:16 PM 11/11/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: Joa Harrison
><flyasuperseven@yahoo.com>
>
>Does anybody know if you need to jumper terminal 1 and/or use the LR & BO
>terminals with the Rotax 912S ignition system and the ACS A-510-2 switch?
>
>Thanks.
>
>Joa
Wire per Figure Z-17 of
http://www.aeroelectric.com/articles/Rev10/z10.pdf
Bob . . .
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! --
|