Today's Message Index:
----------------------
1. 06:21 AM - Required Length of Fusible Links (mikeeasley)
2. 06:46 AM - Re: Control Stick/Flap Switches (Eric M. Jones)
3. 06:57 AM - Re: Diodes vs. Bi-Directional Zeners for Contactors (Eric M. Jones)
4. 09:40 AM - Re: Battery capacity testing (Ed Holyoke)
5. 09:51 AM - Re: Diodes vs. Bi-Directional Zeners for Contactors (Robert L. Nuckolls, III)
6. 09:59 AM - Re: Diodes vs. Bi-Directional Zeners for Contactors (user9253)
7. 10:01 AM - Re: Required Length of Fusible Links (Robert L. Nuckolls, III)
8. 10:10 AM - Re: Control Stick/Flap Switches (Tim Olson)
9. 10:43 AM - Flap Switch Location (John Markey)
10. 10:43 AM - Re:Battery Capacity Testing (Richard Dudley)
11. 11:13 AM - Re: Control Stick/Flap Switches (Bill Mauledriver Watson)
12. 11:13 AM - Re: Flap Switch Location (Bruce Gray)
13. 11:42 AM - Re: Diodes vs. Bi-Directional Zeners for Contactors (Robert L. Nuckolls, III)
14. 11:52 AM - Re: Re:Battery Capacity Testing (Carlos Trigo)
15. 12:26 PM - Re: Wig-Wagging LED lamps (Speedy11@aol.com)
16. 12:26 PM - Re: Bi-Directional Zeners for Contactors (gmcjetpilot@yahoo.com)
17. 12:43 PM - Re: Wig-Wagging LED lamps (Speedy11@aol.com)
18. 12:58 PM - Re: Re: Bi-Directional Zeners for Contactors (mikeeasley)
19. 01:24 PM - Re: Re: Diodes vs. Bi-Directional Zeners for Contactors (Robert L. Nuckolls, III)
20. 01:27 PM - Re: Re:Battery Capacity Testing (Richard Dudley)
21. 01:33 PM - Re: Battery capacity testing (Robert L. Nuckolls, III)
22. 01:38 PM - Re: Wig-Wagging LED lamps (XeVision)
23. 03:44 PM - Re: Re: Bi-Directional Zeners for Contactors (Bob Meyers)
24. 06:33 PM - Re: Control Stick/Flap Switches (Speedy11@aol.com)
25. 06:33 PM - Re: Control Stick/Flap Switches (Speedy11@aol.com)
26. 07:18 PM - 2 Alternator Split System (al38kit)
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 |
|
| Subject: | Required Length of Fusible Links |
B&C sells fusible links that are intended to be 5-6" long. Do they have to be
that long? Do you need to allow any space around them for the heat when they
smoke? If you're protecting a #22 wire, do you go to #26 in the fusible link?
Thanks,
Mike Easley
Colorado Springs
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: Control Stick/Flap Switches |
A note on control stick switches:
Make sure they are environmentally sealed for the harshest jungle-like conditions
encountered under sweaty palms.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=267735#267735
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: Diodes vs. Bi-Directional Zeners for Contactors |
Bob N., you are truly to be admired for the limitless energy you have put into
this subject. I don't know how you do it.
I sell "SnapJacks" bi-directional zeners for putting across the coils of relays,
inductors, and especially contactors--as recommended by Tyco, Potter and Brumfield,
Megavac, Kilovac, and virtually all other relay engineers who have ever
looked at the problem.
But hey, you could be right! One lone voice in the wilderness. I admire you.
"Every act of conscious learning requires the willingness to suffer an injury to
one's self-esteem...."
-Thomas Szasz
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=267737#267737
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: | Re: Battery capacity testing |
Howdy,
I recently subjected the Concord RG-25XC in our RV to an unscheduled
deep discharge test by way of leaving the E-buss switch on for a couple
of days on the ramp at West Yellowstone. We jump started the airplane
with a car, but as soon as the cables were removed, there was nothing on
the panel. Apparently the battery was so dead that the alternator didn't
kick in. I failed to notice if the alternator was running with the
jumper cables connected, but I think it must have been. All the normal
lights and gages were working prior to disconnection.
We called National Aircraft Parts Association and had them send over a
"snowmobile battery", a Yaesu 18ah sized like a PC680 and that got us
going. We hauled the dead Concorde RG-25XC home and I charged it up. I
did a capacity check on it with a West Mountain Radio CBA II tester down
to 10.5 volts, just as I do at annual, and it did pretty well. It
produced 28 ampere hours at a 4amp draw. Not bad for a 24AH battery!
When tested at the most recent annual inspection, it put out just over
30, so it may be slightly degraded, but still very good. We only need
about 16AH to be able to keep the electronic ignition and some of the
more important bits of avionics working 'till we run out of gas, so this
battery still has a ways to go before replacement. I'll save the 18AH
Yaesu for other uses.
Pax,
Ed Holyoke
> The battery is subject to no more stresses than
> situations where you've jump started your car
> because the headlights were left on. Would the
> battery last longer had it never been subjected
> to the deep discharge event? Arguably yes . . . but
> by so small a value as to be difficult to measure
> and totally insignificant to your operational perceptions.
> But it's not an undue stress on the ship's accessories.
> They are all qualified to perform to nameplate ratings
> when the airplane was awarded a type certificate.
>
>
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: | Re: Diodes vs. Bi-Directional Zeners for Contactors |
At 08:56 AM 10/13/2009, you wrote:
Bob N., you are truly to be admired for the limitless energy you have put
into this subject. I don't know how you do it.
See philosophical snippet in my signature . . .
I sell "SnapJacks" bi-directional zeners for putting across the coils of
relays, inductors, and especially contactors--as recommended by Tyco,
Potter and Brumfield, Megavac, Kilovac, and virtually all other relay
engineers who have ever looked at the problem.
But hey, you could be right! One lone voice in the wilderness. I admire you.
Eric my friend. You've missed the point of this discussion
since day-one. This isn't about Bob N. or anyone else being
"right" or "wrong" . . . it's about understanding simple-ideas
and crafting a recipe for success conforming to design goals.
Yes, the folks at all the big houses have the opportunity
to know more about their products than anyone else. Certainly
there was a time that was true. Except for Microswitch, virtually
all of my requests for investigative assistance in a relay or
switch failure over the last 15 years produced a young, wet-behind-
the-ears visitor from the company who was probably a recent graduate.
He/she was assigned support on the legacy products. A sure
bet. No? The legacy products have decades of market history.
Nothing can go wrong . . . go wrong . . . go wrong. They had
never designed a thing, never conducted a failure analysis,
and had no customer or field service experience. They were
seldom accompanied by a learned mentor.
This sad condition is being repeated throughout a once
capable and competent community of suppliers to US
industry. I could have treated these experiences as
either a burden or opportunity. Given that the issues
were costing my employer $millions$, it was good that
I was willing and able to rise to the OPPORTUNITY to
observe, discover, learn and ultimately teach. More often
than not, my discoveries produced facts of performance
that the factory support folks didn't understand.
Further, it was NOT in their best interests to admit
that their capabilities were found lacking. Put yourself
in their shoes . . . you're right out of college. First
job with Mister Big Relays and Contactors, Inc. You
walk back into your office and tell your boss, "The
customer knows more about the product I understand
or was able to offer."
You (and others) have cited the writings by employees
of Mr. Big and (without understanding the significance
of their words) have parroted them back to support
some opinion. Further, you and others have evolved
products base on the same cursory citations.
I have endeavored to test, measure, observe, and
analyze the behaviors switches, relays and contactors
for the purpose of achieving understanding and
offering the best-I-know-how-to-do advice. For
quit a few years, I was well paid by my employers
to carry out such studies.
If you find my offerings lacking, how about offering your
own analysis of the repeatable experiments I've conducted
and/or the data collected therefrom? I'll have to
look back over our writings on this topic but I
can't recall that you have ever offered a data point
discovered by yourself backed up with documentation
on a repeatable experiment.
While I attempt to offer analysis and advice based
on demonstrable fact, you seem content to whack
me about the head and shoulders with Mr. Big's
technical papers that may contain errors of
fact or interpretation. It may be true that the
paper on small mil-spec relays is not directly
related to our discussions about large contactors
used on a OBAM light aircraft.
"One voice in the wilderness" ????? This isn't
a wilderness my friend. It's the universe. The whole
universe runs on physics. Each concept in physics
is a simple-idea. Combining those simple-ideas into
useful recipes for success is what skilled product
development is all about.
I've not said that the latest-greatest spike suppression
techniques do not perform as advertised. What I have
said is that these products are being marketed based
on FEAR of loss of RELIABILITY. I have endeavored to
deflect worries about reliability by encouraging
confidence in failure tolerant design. Confidence
built on understanding that applying the latest-
and-greatest will produce no observable benefit for
the applications we're developing. If you have
a vision about how simple-ideas can be more effectively
used, let's talk about it. If you find any error of
interpretation of the data I've gathered and posted,
nobody would be more pleased to know about it than I.
Please don't remake this into a Friday night wrestling
exhibition between between myself and Mr. Big's
writers . . . or anyone else.
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: | Re: Diodes vs. Bi-Directional Zeners for Contactors |
TYCO's document at http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf
says, "It is the velocity of the armature that is most affected by coil suppression.
If the suppressor provides a conducting path, thus allowing the stored energy
in the relay's magnetic circuit to decay slowly, the armature motion will
be retarded and the armature may even temporarily reverse direction."
TYCO's document seemed credible until the above paragraph. How can a relay start
to drop out, then reverse direction? Where does the power come from to do
this? Using a diode for arc suppression, the relay will start to drop out when
the voltage decays to some point less than 12 volts. In order for the relay
to reverse direction, the voltage will have to increase. But how could it increase?
The voltage has already decayed to the point where the relay drops out,
and the diode is still shorting out what little energy is left. It is common
knowledge that a relay requires a higher voltage to pull in than to drop out.
TYCO is suggesting the impossible. Making that ridiculous statement makes
one question the validity of the whole document. The table showing the drop
out times of various suppression devices does not make it clear exactly what time
interval was measured. Was it the interval from when power to the coil was
first shut off to the time that the contacts were fully opened? If so, that
time is irrelevant to arcing of the relay contacts. The only time interval of
concern is from when the relay contacts first start to open until they are open
far enough to quench the arc. The important thing is, how much longer do
relay contacts arc when using diode compared to using a zener? And is that time
difference significant in our application?
I agree with Bob. The TYCO article is BS.
Mike Easley and Colyn Case are concerned about the arc-suppression diode shorting
out across the main contactor. A 22awg wire can be used from the contactor
fat terminal to the coil terminal, then a 18awg from the other side of the coil
into the cockpit. In case of an unlikely short, the 22awg wire will burn open
first, keeping smoke on the engine side of the firewall.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=267757#267757
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: | Re: Required Length of Fusible Links |
At 08:12 AM 10/13/2009, you wrote:
>B&C sells fusible links that are intended to be 5-6" long. Do they
>have to be that long? Do you need to allow any space around them
>for the heat when they smoke? If you're protecting a #22 wire, do
>you go to #26 in the fusible link?
Fusible links should not be used to generally replace
fuses or circuit breakers. They are used only when
a ROBUST feeder protection is needed. These might
be properly called Micro-ANL current limiters.
If you're considering an application other than
one illustrated in the Z-figures, let's
discus it here on the List.
6" is a good length for meeting the thermal
model that controls the fusing event. You
COVER them in a material capable of containing
the fusing event. Hence the fiberglas/silcone
jacket in the B&C kit. #26 wire is too fragile
to be practical for a/c wiring. #24 is marginal
but okay in applications illustrated.
I've often thought I should not have introduced
the fusible link to the OBAM aircraft community
but then, it's just a collection of simple-ideas
with specific but LIMITED applicability to our
design goals. Let's not start scattering these
guys around the airplane. If you need an isolated,
single strand not conveniently protected by
a fuse at the bus, then consider an in-line
fuse holder.
http://aeroelectric.com/Pictures/Fuses/Fuse_Holders/ifh-2.jpg
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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: | Re: Control Stick/Flap Switches |
Absolutely agree with that one Bruce! A co-policy I have is
that all control moving circuits should have breakers, not
fuses, because you want them pull-able.
Tim Olson - RV-10 N104CD
Bruce Gray wrote:
>
> It's a bad idea to put control of any function on a control stick that
> if inadvertently activated could jeopardize the safety of the aircraft.
>
> Bruce
> www.Glasair.org
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
> Bradburry
> Sent: Monday, October 12, 2009 1:02 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Control Stick/Flap Switches
>
> <bbradburry@bellsouth.net>
>
> I have a flap switch wired thru a couple of relays to raise and lower
> the
> flaps. The switch is a double pole double throw type.
> I just installed an Infinity grip and there is a single throw single
> pole
> switch on the grip that I would like to wire into the system to also
> control
> the flap. I realize the in order to use either switch, the other switch
> will have to be off.
> The problem is that I am electron deficient and have no idea of how to
> wire
> this up. Any help from the list would be greatly appreciated.
>
> Bill B
>
>
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 |
|
| Subject: | Flap Switch Location |
The gentleman who built my wonderful Glasair II put the flap switch next to the
throttle.
While keeping my hand on the throttle in the pattern, I can readily activate the
flap up/down with my thumb. Otherwise, it is offset enough to not be in the
way.
The 3-axis trim is on the stick, and this is plenty to adjust with my left hand,
especially on base and short final.
Bottom line: I agree with the previous post; keep the flap off of the stick.
John
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:Battery Capacity Testing |
For what it is worth, here are my battery endurance procedure
experiences.
For the first and second annual condition inspections of my RV-6A, I
decided to follow the procedure of replacing my 17/18 AH RG battery
rather than do an endurance check. The battery had cost only $50 and I
treated it as expendable.
Meanwhile, after the second condition inspection, I conducted
experiments on the replaced battery. Based on measured current draw of
the avionics and instruments that I considered necessary in the event of
an alternator failure I used automobile lights in parallel to simulate a
load equivalent to the expected current drain.. I confirmed the current
drawn with that load. Then I monitored the voltage and the time until
the battery reached 11 volts. It turned out that with a current of about
9 amps, I had 1.5 hours endurance on a battery that had been used for a
year. This pretty much agreed with the published endurance curves for
that battery.
For the third condition inspection, I decided to test the year-old
battery in place in the aircraft. To accomplish this, I switched on the
"endurance" bus, turned on the avionics and instruments that I
considered essential after alternator failure. I then monitored voltage,
the avionics and time. The result was similar to the earlier simulation
with the auto lamps: the avionics went out at about 1.5 hours.
Since this test was over in an hour and a half, only a voltmeter and
clock were needed to gather data and the battery was re-charged in a
reasonable time via my external power jack. This convinced me that the
battery could be used until the next condition inspection.
Should anyone wonder during the second year about the battery endurance,
the test could be conducted at any time with the expenditure of a couple
of hours.
Regards,
Richard Dudley
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: Control Stick/Flap Switches |
Tim, I realize that I've followed the same policy in my fuse-centric
panel. Or at least I think I have.... So to compare notes:
I have 4 pull-able/reset-able breakers in my panel:
- (2) for the 2 B&C alternator controllers for proper operation of the
crow bar OV protection
- (1) for my flaps with FPS
- (1) for my AP
The rest are all fuses on a 2 bus Z-14
I didn't have a policy per se, but my thinking for the 2 latter fuses was:
- the flap motor could be overpowered by extension at high speeds - so a
reset-able capability is desirable since it is a control surface
- The pull-able breaker gives me an emergency off switch for the autopilot
I should add that I have the Safety Trim system which has a trim shut
off and other safety related functions.
Tim Olson wrote:
>
> Absolutely agree with that one Bruce! A co-policy I have is
> that all control moving circuits should have breakers, not
> fuses, because you want them pull-able.
>
> Tim Olson - RV-10 N104CD
>
>
> Bruce Gray wrote:
>> <Bruce@Glasair.org>
>>
>> It's a bad idea to put control of any function on a control stick that
>> if inadvertently activated could jeopardize the safety of the aircraft.
>>
>> Bruce
>> www.Glasair.org
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
>> Bradburry
>> Sent: Monday, October 12, 2009 1:02 PM
>> To: aeroelectric-list@matronics.com
>> Subject: AeroElectric-List: Control Stick/Flap Switches
>>
>> <bbradburry@bellsouth.net>
>>
>> I have a flap switch wired thru a couple of relays to raise and lower
>> the
>> flaps. The switch is a double pole double throw type.
>> I just installed an Infinity grip and there is a single throw single
>> pole
>> switch on the grip that I would like to wire into the system to also
>> control
>> the flap. I realize the in order to use either switch, the other switch
>> will have to be off.
>> The problem is that I am electron deficient and have no idea of how to
>> wire
>> this up. Any help from the list would be greatly appreciated.
>>
>> Bill B
>>
>>
>
>
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: | Flap Switch Location |
Yep, that's where I put mine also.
Bruce
www.Glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of John
Markey
Sent: Tuesday, October 13, 2009 1:37 PM
Subject: AeroElectric-List: Flap Switch Location
The gentleman who built my wonderful Glasair II put the flap switch next
to the throttle.
While keeping my hand on the throttle in the pattern, I can readily
activate the flap up/down with my thumb. Otherwise, it is offset enough
to not be in the way.
The 3-axis trim is on the stick, and this is plenty to adjust with my
left hand, especially on base and short final.
Bottom line: I agree with the previous post; keep the flap off of the
stick.
John
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: Diodes vs. Bi-Directional Zeners for Contactors |
I'm interested in comments on the relative merits of using diodes vs.
bi-directional zeners. Also, the failure modes of both devices. And
how to size the bi-directional zeners to minimize the chance of a
failure, especially a short failure.
What would happen if either were fail shorted due to high voltage?
Excellent question . . . and the answer goes directly
to countless studies and adjustment of design goals
for the purpose of producing an ACCEPTABLE reliability
factor (generally stated in failures per flight hour).
Any time we can deduce that the failure rate is better
than 1 in 10 to the minus 6 failures per flight hour
(i.e. 1,000,000 flight hours per failure), the guys
who worry about such things relax a lot.
Now, does such a determination say that all components
under study will last 1,000,000 hours? No, the
testing and calculations tell us that the AVERAGE
failure rate for a large population of identical
components is 1,000,000 hours per failure or better.
If you have a device fail in 500,000 hours, then
other components of that population will have to
do better than 1,000,000 hours for the average to
hold.
Experience shows us that robust and otherwise new
components which fall victim to errors of manufacturing
process will fail early (infant mortality) . . . especially
if operated at or just above extreme stress ratings
for that device. This process is called "screening"
and is the basis for Mil-Std-883 qualified components
favored in critical military and space programs. The
screening process is designed to precipitate infant
mortality failures.
Even then, some folks paid to worry will sandbag their
design goals by telling suppliers to DE-RATE their
already screened 883 components by some factor. Resistors
will be de-rated to 1/2 power. Capacitors operated at
1/2 rated voltage, etc. etc.
I've smiled when reading the purchase specs driven
by such worries. Virtually every product failure
over which I was given direction turned out to be
an error in design or process, not a failure of component
to meet requirements for which it was properly designed
and qualified. It seems like the guy turning the wrenches
is still the riskiest ingredient in the recipe. So let's
potential for stress induced failure of a diode across the
coil of a contactor. See:
http://www.fairchildsemi.com/ds/1N/1N4001.pdf
For the most part, we're building 14v airplanes with
a sprinkling of 28v. Okay, a 50v rated diode will have
a 2x headroom in a 28v airplane, 3.5x in a 14v airplane.
For a few cents more, one COULD install a 600V rated diode.
Man, talk about de-rating!
On the conduction side of the study, the typical 1A
diode (1N400x series) is designed and qualified to
conduct 1A at a max voltage drop of 1.1 volts. Okay,
this is 1.1 watts of heat being dumped out in that
diminutive glass or plastic package. Now, we never
SEE that 1.1 volts under our anticipated usage.
But let's take worst case.
CAPACITORS charge to some voltage will deliver that
SAME voltage at potentially HIGH current during
the discharge cycle. INDUCTORS charged to some current
will deliver that SAME current at potentially HIGH
voltage during their discharge cycle.
Now, here's an el-cheeso battery contactor running
coil current of .6 to 1.0 amps. When the circuit
is broken, we can expect a PULSE of current at no
more than 1.0 amps. Further, the duration of that
current is on the order of 200 milliseconds ramping
down from 1.0 amps to zero. Let's assume an AVERAGE
of 0.5 Amps over 200 milliseconds with a maximum
voltage drop of 1.1 volts. Hmmm . . . that's a worst
case value of 110 milljoules of energy over 0.2 seconds
dumped into a device DESIGNED to dissipate 1100 millijoules
of energy every second for an indefinite period of time.
May I suggest that this too is an exceedingly conservative
de-rating philosophy?
So while we're discussing potential failure modes
for becoming either shorted or open, let us not loose
our grip on probability of failure based on the expected
stresses versus stresses defined by the device's
design. Devices used for coil spike suppression are
VERY lightly taxed and therefore exceedingly low
failure rates.
Short answer is that "sizing" of these components
based on their electrical characteristics is a
exercise in no-value-added-worrying. I prefer to
size them for mechanical robustness as illustrated
many places in my writing and illustrating. The
beefier 1N5400 series devices are less likely to
be damaged by over-enthusiastic wrench turning.
Whether you use zeners-diode combos, bi-directional
Transorbs, resistors, diodes, etc will have no
observable effect on system reliability based on
ratings. But beating the little guys up with
wrench or hammer is another matter. The more
valid worry is not WHAT you use but HOW you
use it.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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:Battery Capacity Testing |
Perhaps a dumb question about a small detail, but to conduct these
capacity
tests, how did you measure the time, were you one and a half hours
looking
at the voltmeter to see when it reached the 11V?
Carlos
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Richard
Dudley
Sent: ter=E7a-feira, 13 de Outubro de 2009 18:36
Subject: AeroElectric-List: Re:Battery Capacity Testing
For what it is worth, here are my battery endurance procedure
experiences.
For the first and second annual condition inspections of my RV-6A, I
decided
to follow the procedure of replacing my 17/18 AH RG battery rather than
do
an endurance check. The battery had cost only $50 and I treated it as
expendable.
Meanwhile, after the second condition inspection, I conducted
experiments on
the replaced battery. Based on measured current draw of the avionics and
instruments that I considered necessary in the event of an alternator
failure I used automobile lights in parallel to simulate a load
equivalent
to the expected current drain.. I confirmed the current drawn with that
load. Then I monitored the voltage and the time until the battery
reached 11
volts. It turned out that with a current of about 9 amps, I had 1.5
hours
endurance on a battery that had been used for a year. This pretty much
agreed with the published endurance curves for that battery.
For the third condition inspection, I decided to test the year-old
battery
in place in the aircraft. To accomplish this, I switched on the
"endurance"
bus, turned on the avionics and instruments that I considered essential
after alternator failure. I then monitored voltage, the avionics and
time.
The result was similar to the earlier simulation with the auto lamps:
the
avionics went out at about 1.5 hours.
Since this test was over in an hour and a half, only a voltmeter and
clock
were needed to gather data and the battery was re-charged in a
reasonable
time via my external power jack. This convinced me that the battery
could be
used until the next condition inspection.
Should anyone wonder during the second year about the battery endurance,
the
test could be conducted at any time with the expenditure of a couple of
hours.
Regards,
Richard Dudley
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 |
|
| Subject: | Re: Wig-Wagging LED lamps |
My apology, Mr/Ms/Mrs dblumel. I meant no offense to XeVision. You make
an excellent product. In fact, I likely would have bought it at Sun n Fun
several years ago except that the guy working your booth was quite rude.
So, I went to the Precise Flight booth and found an opposite response. I
bought their product.
I don't know where Precise Flight buys their bulbs, but I do know they work
very well for my application (RV-8A). I do plan to upgrade to the 50 or
70W version. I do not work for Precise Flight nor have any working or
financial relationship with them.
My LED recognition lights can easily be seen 5 miles away, but they are
very directional. At that distance they have to pointed at you to be seen.
Within 1 mile, they can be seen about 30-40 degrees off center. If one
designs reflective material into the lamp assembly, the angle-off visibility
improves.
Stan Sutterfield
XeVision developed and made available 50 watt HID in early 2005 and 75
watt HID
about 2 years ago for special applications.
Both the 50 and 75 watt HID from XeVision are used in the Eurocopter line
of Helicopters
within their TC and as an upgrade.
Note: the industry std. is to rate this HID technology based on Watts
output (to
the bulb), not using input to the ballasts as the rating. This is a common
problem
with Asian made HID products and their wattage ratings.
The ONLY quality HID bulbs in the 35-75 watt range are made in Europe. The
Asians
including Korea are a long way from matching the QC, life and performance
provided
by Philips, Osram (Sylvania) and GE HID bulbs.
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: Bi-Directional Zeners for Contactors |
The EV200 is a different animal from the ubiquitous-coil/solenoid/contact
or. I did lots of
research on this. Notice the activation and latched current? Very small. Yo
u don't
need diodes. The EMF part, I'm-not sure about. The diode on the classic c
ontactor is
to suppress the voltage spike from the collapsing field, thus protecting th
e switch from arching and-reduced life and failure.
-
I don't recall the details, but the EV200 uses different mechanical geometr
y and electro-
magnetism activation and scheme that is more efficient, while maintaining r
idiculous power
specs.
-
I also looked at the cost v benefit. On a Lancair, cost no object, EV200 wh
y not. For the
average home built, even my RV7 the standard contactors are fine. Still the
price of the
EV200 has come way down; it's an attractive option now, especially for savi
ng weight. It
does not weigh a lot less it self versus a standard contactor, but it uses
about +0.50 amps
less to stay latched. For guys trying to fly day/night deluxe VFR with a li
ghter wight-30 or
40 amp alternator, every 0.50 amp counts.
-
These are my opinions. If you don't like them, request a refund for what yo
u paid for it.
-
Cheers.
-
-
>From: mikeeasley <mikeeasley@aol.com>
>Subject: AeroElectric-List: Diodes vs. Bi-Directional Zeners for Contactor
s
>I'm building a new power grid for a customer and the research on contactor
s ended
>up with some digging on the diodes that we use across the coils of the con
tactors,
>and whether they're necessary.- We're using a couple Tyco Kilovac EV200s
>and since they have pigtail wires instead of terminals, it's tougher to in
stall
>the diodes.- Tyco says we don't need "back EMF protection" with the EV20
0s.
>But we are also using the LEV100 contactors, which do need the back EMF pr
otection.=0A=0A=0A
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: Wig-Wagging LED lamps |
In a word - no.
LEDs are still relatively expensive - especially when the word airplane is
associated with it.
I was able to accomplish what you described, but at a cost of $600+
Prices are dropping, but not rapidly.
However, consider using 12v MR-16 bulbs. They are lightweight, cheap,
bright, easy to install, and readily available. The major drawback is heat.
They get VERY hot. You would need to ventilate them. They get much hotter
than LEDs, which themselves must be use heat sinks.
There are many types or MR-16s - some with IR lenses, some without, some
that let the IR out thru the reflector, some that send all IR out the front,
some that are blue tinted to give a blue light, 50w, 35w, 75w, spot,
flood, wide ... lots of variables.
Before buying the LEDs, I had settled on the 65W, 12 degree spot MR-16 bulb
with a plan to add a 12v computer fan to help cool it.
Stan Sutterfield
"Cheap", let's say $50 dollars for each LED assy so $100 total (both
wings).
"Bright", let's say easily noticed wig-wagging from at least 2-3 miles
away,
within a 20-30 deg angle from head-on.
Ralph Finch
Davis, California
RV-9A QB-SA
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: | Re: Bi-Directional Zeners for Contactors |
The Tyco EV200 has built-in back EMF suppression according to the engineer at Tyco
Kilovac. I didn't ask him what kind of suppression, but he confirmed that
it wasn't necessary to have any external suppression. The LEV series needs external
suppression. The EV series has a circuit that reduces coil amperage once
it closes also.
Mike Easley
Colorado Springs
In a message dated 10/13/09 13:27:27 Mountain Daylight Time, gmcjetpilot@yahoo.com
writes:
The EV200 is a different animal from the ubiquitous coil/solenoid/contactor. I
did lots of
research on this. Notice the activation and latched current? Very small. You don't
need diodes. The EMF part, I'm not sure about. The diode on the classic contactor
is
to suppress the voltage spike from the collapsing field, thus protecting the switch
from arching and reduced life and failure.
I don't recall the details, but the EV200 uses different mechanical geometry and
electro-
magnetism activation and scheme that is more efficient, while maintaining ridiculous
power
specs.
I also looked at the cost v benefit. On a Lancair, cost no object, EV200 why not.
For the
average home built, even my RV7 the standard contactors are fine. Still the price
of the
EV200 has come way down; it's an attractive option now, especially for saving weight.
It
does not weigh a lot less it self versus a standard contactor, but it uses about
+0.50 amps
less to stay latched. For guys trying to fly day/night deluxe VFR with a lighter
wight 30 or
40 amp alternator, every 0.50 amp counts.
These are my opinions. If you don't like them, request a refund for what you paid
for it.
Cheers.
>From: mikeeasley <mikeeasley@aol.com>
>Subject: AeroElectric-List: Diodes vs. Bi-Directional Zeners for Contactors
>I'm building a new power grid for a customer and the research on contactors ended
>up with some digging on the diodes that we use across the coils of the contactors,
>and whether they're necessary. We're using a couple Tyco Kilovac EV200s
>and since they have pigtail wires instead of terminals, it's tougher to install
>the diodes. Tyco says we don't need "back EMF protection" with the EV200s.
>But we are also using the LEV100 contactors, which do need the back EMF protection.
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: | Re: Diodes vs. Bi-Directional Zeners for Contactors |
At 11:58 AM 10/13/2009, you wrote:
>
>TYCO's document at
>http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf
>says, "It is the velocity of the armature that is most affected by
>coil suppression. If the suppressor provides a conducting path, thus
>allowing the stored energy in the relay's magnetic circuit to decay
>slowly, the armature motion will be retarded and the armature may
>even temporarily reverse direction."
>
>TYCO's document seemed credible until the above paragraph.
<snip>
>I agree with Bob. The TYCO article is BS.
Very astute observations sir. And they
agree with my own . . . along with conditions
I measured on the bench. Drop-out
delay is strongly influenced by current
decay in the coil when the armature is
seated. Contact spreading velocity is a
function of BOTH coil current AND
the AIR-GAP in the magnetic path once the
armature becomes unseated. An air gap in
any magnetic pathway has a huge effect. Reverse
direction? Yeah, right.
So once you allow coil current to fall
just enough to unseat the armature, the rate
at which the armature accelerates is more
strongly influenced by the air-gap than
by decay in magnetic field. I WAS able to
detect perhaps 2 or 3% increase in spreading
velocity for "fancy" versus "hammer-n-tongs"
coil suppression . . . too small to be
significant terms of service life.
I also used a fast 'scope to observe differences
in arcing during the contact break without
and then with various coil suppression techniques.
Yes, there were differences. So small and so
variable that I couldn't hang my hat on coil
suppression as having any observable effect
on service life of the CONTACTORS and LARGE
RELAYS under investigation.
These simple-ideas can be observed and
combinational effects duplicated . . . as
well they should be. It's the repeatable
experiment that determines whether you
have a souffle, scrambled-eggs and cheese,
or garbage.
Your attention to detail sir is commendable.
Bob . . .
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:Battery Capacity Testing |
Hi Carlos,
The short answer is: yes. I used a stop watch function on my wristwatch.
In the first capacity tests with the dummy load of auto lamps, I checked
the voltage at convenient intervals like 10 minutes until it approched
11 volts because I was unsure what to expect. I even plotted the data.
When it started to change more rapidly I checked more often. From fully
charged, around 12.7 volts to near 11 volts, the change is very slow.
Near 11 volts, the decline is quite rapid.
After I knew better what to expect, during the actual tests in the plane
in the hangar, I just checked the voltage periodically and noted when
the avionics failed. It was part of my condition inspection tests so, I
had other things to do on the plane.
There are plenty of fancier automated ways to test without personally
monitoring. (Bob Nuckolls has published a timer that will count until
the battery voltage drops to a predetermined voltage.) However, I felt
that I could "squander" an hour and a half once a year looking at a
voltmeter and my watch, and even multitasking with other tasks I had in
the hangar.
Regards,
Richard
----- Original Message -----
From: Carlos Trigo
To: aeroelectric-list@matronics.com
Sent: Tuesday, October 13, 2009 2:44 PM
Subject: RE: AeroElectric-List: Re:Battery Capacity Testing
Perhaps a dumb question about a small detail, but to conduct these
capacity tests, how did you measure the time, were you one and a half
hours looking at the voltmeter to see when it reached the 11V?
Carlos
-------------------------------------------------------------------------
-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Richard Dudley
Sent: ter=E7a-feira, 13 de Outubro de 2009 18:36
To: aeroelectric-list@matronics.com
Subject: AeroElectric-List: Re:Battery Capacity Testing
For what it is worth, here are my battery endurance procedure
experiences.
For the first and second annual condition inspections of my RV-6A, I
decided to follow the procedure of replacing my 17/18 AH RG battery
rather than do an endurance check. The battery had cost only $50 and I
treated it as expendable.
Meanwhile, after the second condition inspection, I conducted
experiments on the replaced battery. Based on measured current draw of
the avionics and instruments that I considered necessary in the event of
an alternator failure I used automobile lights in parallel to simulate a
load equivalent to the expected current drain.. I confirmed the current
drawn with that load. Then I monitored the voltage and the time until
the battery reached 11 volts. It turned out that with a current of about
9 amps, I had 1.5 hours endurance on a battery that had been used for a
year. This pretty much agreed with the published endurance curves for
that battery.
For the third condition inspection, I decided to test the year-old
battery in place in the aircraft. To accomplish this, I switched on the
"endurance" bus, turned on the avionics and instruments that I
considered essential after alternator failure. I then monitored voltage,
the avionics and time. The result was similar to the earlier simulation
with the auto lamps: the avionics went out at about 1.5 hours.
Since this test was over in an hour and a half, only a voltmeter and
clock were needed to gather data and the battery was re-charged in a
reasonable time via my external power jack. This convinced me that the
battery could be used until the next condition inspection.
Should anyone wonder during the second year about the battery
endurance, the test could be conducted at any time with the expenditure
of a couple of hours.
Regards,
Richard Dudley
http://www.matronics.com/Navigator?AeroElectric-Listhttp://forums.matroni
cs.comhttp://www.matronics.com/contribution
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: | Re: Battery capacity testing |
Ed and Richard,
Good job gentlemen! A fine thinker and craftsman of repeatable
experiments once opined:
"When you can measure what you are speaking about, and express
it in numbers, you know something about it; but when you cannot
measure it, when you cannot express it in numbers, your knowledge
is of a meagre and unsatisfactory kind; it may be the beginning
of knowledge, but you have scarcely in your thoughts advanced
to the state of Science." -Lord Kelvin-
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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: | Re: Wig-Wagging LED lamps |
Stan, my name is Dan (Male).
Your comment is rather "interesting" in light of the fact that we have NEVER had
a booth at Sun N Fun, in fact we (nor I or any employee) have never even attended
Sun N Fun. So I am not sure how we could have been rude to you or anyone
else at "our booth".
Precise Fight uses Osram (Sylvania) brand D1S HID bulbs for their 35 watt applications.
This bulb is made in Germany.
Dan
[quote="Speedy11(at)aol.com"]My apology, Mr/Ms/Mrs dblumel. I meant no offense
to XeVision. You make an excellent product. In fact, I likely would have bought
it at Sun n Fun several years ago except that the guy working your booth
was quite rude. So, I went to the Precise Flight booth and found an opposite
response. I bought their product.
I don't know where Precise Flight buys their bulbs, but I do know they work very
well for my application (RV-8A). I do plan to upgrade to the 50 or 70W version.
I do not work for Precise Flight nor have any working or financial relationship
with them.
My LED recognition lights can easily be seen 5 miles away, but they are very
directional. At that distance they have to pointed at you to be seen. Within
1 mile, they can be seen about 30-40 degrees off center. If one designs reflective
material into the lamp assembly, the angle-off visibility improves.
Stan Sutterfield
> XeVision developed and made available 50 watt HID in early 2005 and 75 watt
HID
> about 2 years ago for special applications.
>
> Both the 50 and 75 watt HID from XeVision are used in the Eurocopter line
of Helicopters
> within their TC and as an upgrade.
>
> Note: the industry std. is to rate this HID technology based on Watts output
(to
> the bulb), not using input to the ballasts as the rating. This is a common
problem
> with Asian made HID products and their wattage ratings.
>
> The ONLY quality HID bulbs in the 35-75 watt range are made in Europe. The
Asians
> including Korea are a long way from matching the QC, life and performance
provided
> by Philips, Osram (Sylvania) and GE HID bulbs.
>
> [b]
--------
LED still has a long way to go to compete with HID as a landing light. This is
true in terms of total lumens and reach (distance).
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=267800#267800
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: Bi-Directional Zeners for Contactors |
That .50 amp savings was why I put one in my Aerovee powered Sonex
with a 20 amp alternator. I had already mounted a fine cheap one from
B&C but I had an opportunity to get one cheap and replace it.
"Scotty, I need more power"
Bob Meyers
Building Sonex 982SX Web Site Index http://meyersfamily.org/Sonex982.html
On Oct 13, 2009, at 2:24 PM, gmcjetpilot@yahoo.com wrote:
> The EV200 is a different animal from the ubiquitous coil/solenoid/
> contactor. I did lots of
> research on this. Notice the activation and latched current? Very
> small. You don't
> need diodes. The EMF part, I'm not sure about. The diode on the
> classic contactor is
> to suppress the voltage spike from the collapsing field, thus
> protecting the switch from arching and reduced life and failure.
>
> I don't recall the details, but the EV200 uses different mechanical
> geometry and electro-
> magnetism activation and scheme that is more efficient, while
> maintaining ridiculous power
> specs.
>
> I also looked at the cost v benefit. On a Lancair, cost no object,
> EV200 why not. For the
> average home built, even my RV7 the standard contactors are fine.
> Still the price of the
> EV200 has come way down; it's an attractive option now, especially
> for saving weight. It
> does not weigh a lot less it self versus a standard contactor, but
> it uses about +0.50 amps
> less to stay latched. For guys trying to fly day/night deluxe VFR
> with a lighter wight 30 or
> 40 amp alternator, every 0.50 amp counts.
>
> These are my opinions. If you don't like them, request a refund for
> what you paid for it.
>
> Cheers.
>
>
> >From: mikeeasley <mikeeasley@aol.com>
> >Subject: AeroElectric-List: Diodes vs. Bi-Directional Zeners for
> Contactors
>
> >I'm building a new power grid for a customer and the research on
> contactors ended
> >up with some digging on the diodes that we use across the coils of
> the contactors,
> >and whether they're necessary. We're using a couple Tyco Kilovac
> EV200s
> >and since they have pigtail wires instead of terminals, it's
> tougher to install
> >the diodes. Tyco says we don't need "back EMF protection" with the
> EV200s.
> >But we are also using the LEV100 contactors, which do need the back
> EMF protection.
>
>
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: Control Stick/Flap Switches |
Bill,
If you can do it, Jim's setup is ideal.
Stan Sutterfield
I have my flap switch on the throttle and trim on the stick. Works great
for
me
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
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: Control Stick/Flap Switches |
Bill,
There is nothing wrong with or dangerous about putting your flap switch on
the control stick. However, one must use due diligence when activating a
switch on the stick when one has more than one switch on the stick. For
example, I have flap switch, trim switch and starter switch all on the top of
my stick. I also have PTT, AP disconnect and smoke on the stick.
However, I've flown fighters for years and I'm comfortable with HOTAS. It would
be easy to accidentally activate the flaps when reaching for the trim (I
disable my starter button with a switch when flying). If the flaps are
accidentally started down, you simply switch them back up immediately.
So, while it is not dangerous to have flaps (or any other switch) on the
stick, it might be prudent to put it on the panel or near the throttle if
you are a private pilot who trained in aircraft that used a panel mounted flap
switch. If you prefer to have switches on the stick, then wire it that
way.
I would tell you how I wired mine, but mine is unique and may not fit your
needs. Is there another builder nearby that can help?
If you can't find help, contact me directly (off the forum) and I'll talk
you through my installation.
Stan Sutterfield
My 2 cents--
Keep the stick simple and place the flap switch on the panel.
Peter
On Mon, Oct 12, 2009 at 1:27 PM, Bruce Gray <Bruce@glasair.org> wrote:
>
> It's a bad idea to put control of any function on a control stick that
> if inadvertently activated could jeopardize the safety of the aircraft.
>
> Bruce
> www.Glasair.org
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
> Bradburry
> Sent: Monday, October 12, 2009 1:02 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Control Stick/Flap Switches
>
> <bbradburry@bellsouth.net>
>
> I have a flap switch wired thru a couple of relays to raise and lower
> the
> flaps. The switch is a double pole double throw type.
> I just installed an Infinity grip and there is a single throw single
> pole
> switch on the grip that I would like to wire into the system to also
> control
> the flap. I realize the in order to use either switch, the other switch
> will have to be off.
> The problem is that I am electron deficient and have no idea of how to
> wire
> this up. Any help from the list would be greatly appreciated.
>
> Bill B
Message 26
| 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: | 2 Alternator Split System |
As I design my system, I have a question regarding which alternator to use to power
the main flight/nav instruments...I'm planning an IFR all electric panel.
I do plan to have back up instruments on the other buss.
I have the small B&C 20 amp gear driven alternator, and a 60 amp PP belt driven.
This will be going on an IO520.
I plan to run the busses, with an interconnect in the event of failure of one of
the alternators.
Which alternator should I plan to power the "more critical" buss?
Does it matter...?
Al
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=267842#267842
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! --
|