Today's Message Index:
----------------------
1. 05:34 AM - Re: Molex connector sexual orientation (Rodney Dunham)
2. 08:07 AM - Re: Comments please on this solid state contactor....... (John Richardson)
3. 03:52 PM - Re: How reliable is reliable (Robert L. Nuckolls, III)
4. 04:13 PM - Re: Re: wiring diagram benefits? (Robert L. Nuckolls, III)
5. 04:51 PM - Rheostat Diagrams (go-fly-away@juno.com)
6. 05:29 PM - Dragging certified aircraft screaming and kicking into the 21st Century (Dave N6030X)
7. 07:36 PM - Re: Popped CB ()
8. 09:35 PM - Non coax to BNC connector. (DEAN PSIROPOULOS)
Message 1
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| Subject: | Molex connector sexual orientation |
Brian,
It doesn't matter at all!
When the two halves are mated together, there is no chance of a short
between the pins and you ALWAYS disconnect the BAT ground before fooling
with ANYTHING elctrical, don't you???
I use these goodies a lot and I seldom put all of one "sex" on one end. I
mix them up so that I can't accidentally connect two connectors that don't
belong together. For instance, on my Blue Sea fuse block I twisted pairs and
assigned the "1" fuse to the "1" pin on my "molex" connector. The
corresponding ground (built in to the Blue Sea fuse block) went to the "2"
pin and so on. Grounds are male and +12V are female. There are 6 fuses on
one side numbered odd 1 through 11 and 6 on the other side numbered even 2
through 12. So... on the even side, the "1" pin is ground (male) and the "2"
pin is +12V (female) and so on... Both shells are female so I cannot
accidentally connect the two together. Besides, if the BAT ground is
disconnected, it wouldn't hurt to do so anyway! Each wire or bundle is
clearly labeled at the connector.
I just make each one unigue and there is a good mix of 2, 3, 4, 6, 9 and 12
pin connectors. No two are the same so it isn't possible to connect anything
wrong. If it fits, it right! Always read the label. And ALWAYS disconnect
BAT ground before working on your plane! Simple.
Rodney in Tennessee
_________________________________________________________________
i'm making a difference.Make every IM count for the cause of your choice.
Join Now.
Message 2
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| Subject: | Comments please on this solid state contactor....... |
Hello Alex
I have installed the EV200 contactor in my Lancair Legacy as the master
contactor after some investigation. I posted a similar question on the list
about a year ago and Bob answered me back (thanks again Bob). He said it
looked good from the data sheet, but very expensive when compared to the
normal contactors from B&C.
I think the current switching and carrying capability is a little over-kill
for our applications in light airplanes. However, in an all electric
system, I think this is not all bad. There's no weight or size penalty.
It's reassuring to note the device has a mechanical life cycle spec and a
cycles under load spec. As a master contactor, most of the load is removed
during the switching event. Load carrying is speced at 200 A continuous and
500 A for 10 sec. However, as a starter contactor, load switching is an
issue but that's where this thing really shines. Because of cost, I ended
up using a regular contactor for the starter.
The coil energizing circuit is unique. It draws about 3 A during coil pull
in then drops back to 0.07 A (24V) to hold. I talked to the design engineer
to learn this low holding current is achieved by a pulsing circuit that
applies the 3 amps at a very low duty cycle. A possible down side of the
pulsing is radio frequency interference. I did a rough test with my
handheld placing the antenna all around the device and the coil leads and
found no interference across the nav and com bands. I'm not flying yet, so
I'm still waiting to conduct the real test. In comparison, a continuous
duty standard contactor I have has coil resistance of about 70 ohms for 24
volt operation. At 28 volts that will draw about 0.4 A and dissipate about
11 watts. Not that much in the big picture. Obviously, the EV200 does not
get hot at all due to coil current. Finally, it's reassuring to note the
coil circuit operates over the range of 9 to 36 volts and will hold in (stay
closed) down to 7.5 volts. In a 24 volt system, this is more than adequate
margin to operate under low bus voltage, even when starting. I think it's
about the same as a 12 v contactor too.
It is definitely a quality component and I'm banking on it keeping my two
Odyssey PC 625 batteries connected to the panel.
Regards,
John Richardson
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alex
Sent: Tuesday, March 13, 2007 5:36 PM
Subject: AeroElectric-List: Comments please on this solid state
contactor.......
I have been testing my electrical system on my all- electric Velocity- with
no load, only the coils energized for about 30 minutes my battery contactors
were both quite hot- too hot to hold for more than say 5 seconds- comments
from other builders agree that this is rather normal- someone suggested the
"Czonka III" solid state unit- uses no appreciable power- good for tens of
thousands of cycles at 200 amps- please see attached PDF- is there any
foreseen drawback other than cost?
Alex
Message 3
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| Subject: | Re: How reliable is reliable |
At 05:10 PM 3/16/2007 -0700, you wrote:
>
>Out of curiosity Bob, would you then mainly advocate z-14 for new designs
>with a 20A alternator. In the past it seems you have suggested z-14 over
>z-12 for people in the planning stages (correct me if I'm wrong). Maybe a
>z-14 that uses the second bus as a smaller main alt. out e-bus, not used
>for starting...smaller battery...
>
>In what instance would you use z-12 over z-14 with a 20A alternator? Save
>a little $ and #?
>
>-Ryan (In the pondering stage)
To my way of thinking, perhaps 1-2% of all OBAM aircraft
under construction will be used in ways that justify a
Z-14 installation. Here's a post I made in 2005 to a similar
question:
------------------------
At 08:46 PM 2/9/2005 +0100, you wrote:
<snip>
>Thank you for your thoughtful reply. The 2 batt/2 alt setup (Z11) did get me
>excited but the type of flying (very occasional dusk VFR, no IFR, over water
>at times) plus a common sensical KISS principle to govern decisions may
>dampen my enthusiasm for Z11.
Let's try to put some things into perspective. There are tons
of dark-n-stormy night stories wherein alternators and batteries
are star performers in the role of villain. Given the proven
reliability of modern automotive alternators . . . in particular
the converted Nipon Denso products from B&C . . . probability
of alternator failure is a small fraction of what we've come to
expect from certified iron. Combine this with the very robust,
sealed lead-acid batteries -AND- a truly meaningful preventative
maintenance plan and we've beat the worst worries into submission.
If one simply installs Van's a-la C-172 wiring with a modern
alternator and well maintained RG battery, probability of
having to take a staring role in a dark-n-stormy night play
due to electrical systems issues is very low.
By taking advantage of variations on a theme described in the
z-figures, one can push those probabilities still lower. In
10+ years of suggesting builders consider the e-bus, I've
had only one reader write and tell me the e-bus turned an
alternator failure into a ho-hum event. However, I've had
perhaps a half dozen people write and thank me for the OVM-14
crowbar ov module. Far more folks have experienced an ov
condition that forced alternator shutdown than simple
alternator failure. I don't recall the numbers of ov
experiences that benefited from an e-bus installation after
the alternator was shut off. Even if the builder did not
have an e-bus, keeping a well maintained RG battery on
board goes a long way to saving the day.
>In the final analysis, I think it all boils down to whether I want full
>electronic ignition, partial, or all mags.
If you go electronic ignition, consider at least one p-mag
which does not depend on electrical system for operation.
>I am finishing the wings which means that I have a long way to go - you'll
>see my posts as the situation evolves.
I have a client with enough funds to strive for the
"ultimate" system which may include dual efis, dual
electronic ignition, dual autopilots . . . For the
moment, I'm still trying to justify ruling out
a Figure Z-13/8 installation thus saving about a 23
pound penalty for going with Z-14.
Reliability doesn't have to be heavy or expensive . . .
just well considered. Since the e-mag/p-mag guys
came along, reliability is getting easier, lighter
and less expensive all the time.
------------------ end of quotation -------------------------
If I owned a certified machine, I would endeavor to
(1) add ACTIVE NOTIFICATION OF LOW VOLTAGE. (2)
install and MAINTAIN an RG battery. (3) Modify
the architecture to turn the avionics bus into an
E-BUS. (4) When an if the stock alternator craps,
I'd get a modern automotive adaptation in place.
These simple changes alone would elevate the spam
can's SYSTEM reliability by a quantum jump. Implementation
of an e-bus/bat-maintenance protocol makes the vast
majority of demonstrated concerns go away. Virtually
every dark-n-stormy night story I've read that concerned
electrical systems would never had been written had
the owner-operators of the subject airplanes availed
themselves of the knowledge and understanding offered
to you here on this List.
Now, if you don't plan to have a vacuum system then
the vacuum pump pad is open and you'll be many watt-hours
ahead in planning for alternator failure by adding the
SD-8 and perhaps even downsizing the battery for a wash
in weight.
Z-13/8 is an exceedingly robust system that should
handle everything you or I would want to do at
reliability levels that far exceed those of the
certified ships that we're ALREADY using do do the
same kinds of flights.
Now, Z-12 and Z-14 have some appeal but I'd recommend
Z-12 only as an upgrade to an existing Z-11 or spam-can
clone and Z-14 for ships like a Lancair IVP with full-up
dual IFR panels.
Obviously, if you have the $time$ and don't mind the
weight, you can pile on as many backups to backups that
suits your worry levels . . . but I'll suggest that
Z-13/8 is the value leader in return for reliability
with the lowest investment in $time$ and loss of
payload.
It would cost more dollars and talented manpower than
you or I are willing to expend to put numbers on the
relative reliability of Z-13/8 vs Z-14 for the various
operating scenarios. But it's my considered judgement
that Z-14 is overkill for most of the OBAM aircraft
under construction.
Bob . . .
Message 4
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| Subject: | Re: wiring diagram benefits? |
At 12:01 AM 3/15/2007 -0400, you wrote:
>Just do it, you'll be happy you did, and may hate yourself if not I will
>do my first flight next week, and so far there have been 3 issues
>regarding electrical stuff which were a piece of cake to track down and
>fix because I took the trouble to do a 6 page diagram with Z11 as a base.
>
>Here's the deal... I wired it last year, and if you think you'll remember
>all those pathways about 2 years after first flight, you have a lot better
>memory than myself.It was a mystery to me until I pulled out my
>handy-dandy wirebook... Voila!!! No problema!!!
This doesn't have to be time consuming or expensive.
Do page per system drawings in pencil and keep a
Pink Pearl eraser handy for corrections. You can
do the drawings in a 3-ring notebook. When the
airplane is done, "fog" the penciled pages with
clear Krylon finish to "set" the pencil for longevity
that rivals ink.
Total time added to your task will be trivial in
the grand scheme of things. Further, as others have
suggested you'll be glad you did it a few years
hence. The wirebook can also cite component part numbers
to make spares procurement easier as well.
Another thing I've been doing for about the last
7 years or so is ordering parts and supplies as
much as possible over the 'net. When an order has
be submitted, you almost always get a screen dump
of the order that includes where you got the parts,
what the numbers are, how much they cost, etc. I
print these screens (or e-mail confirmations) to
pdf files using Adobe Acrobat (other pdf generators
may work as well). Name the file with a date-supplier
protocol like 70320B01_Digikey. This decodes to
Bob's first purchase on March 20, 2007 and placed with
Digikey.
When all these files get dumped into a purchasing
directory, I have a complete history of orders that
sort in date order and can be searched. It takes
seconds to record the order to a common data folder
and a few seconds longer to search later and find
where I purchased an MS21919 clamp or a DPX5050
pressure transducer.
When your airplane is done, you can print out these
files to paper, punch them and put them in the back
of your wirebook too. Takes mere minutes to collect
the information and offers fast access to tons of
maintenance data.
Bob . . .
----------------------------------------
( IF one aspires to be "world class", )
( what ever you do must be exercised )
( EVERY day . . . )
( R. L. Nuckolls III )
----------------------------------------
Message 5
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| Subject: | Rheostat Diagrams |
Hi Bob,
I have your book but am looking for proper use of a rheostat to dim the
annuciators on a KLN 90-B. I have ground plus the annunciator light wir
es. I am having a brain dump on this one. Any suggestions??
Thanks, Mark
<html><P>Hi Bob,</P>
<P>I have your book but am looking for proper use of a rheostat to dim t
he annuciators on a KLN 90-B. I have ground plus the annunciator l
ight wires. I am having a brain dump on this one. Any sugges
tions??</P>
<P>Thanks, Mark</P>
<pre><b><font size=2 color="#000000" face="courier new,courier">
</b></font></pre></body></html>
Message 6
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| Subject: | Dragging certified aircraft screaming and kicking into |
the 21st Century
Bob, for those of us who have certified airplanes and want active
notification of low voltage, EI sells a cheap ($285) voice
annunciator that will say "Check Bus Voltage" in a soft female voice
right into your headset if the voltage drops below 13V, without being
hooked to anything but power. (She'll say 16 other things, too, if
hooked up to various instruments' alarm outputs). It certainly
always gets my attention when I chop the power on approach and switch
on the landing light and she reminds me that I'm now sucking some
battery power.
Also there may be some people who think the annual battery condition
test is a complicated process that requires construction of devices
with light bulbs and timers and things. I did it yesterday without
removing the battery from the airplane. You can do it by replacing
whatever crappy ammeter came with your airplane with a Volt-Ammeter
like the one from EI. I simply switched on the master and enough
additional devices to pull about 4.5A of current (which I have
determined in advance is more than sufficient for a daytime VFR cross
country in my plane), and then checked back every 15 minutes to see
how the voltage was holding up. After 90 minutes, I stopped the
test, as the voltage was still holding at 11.81 Volts. That gave me
the warm fuzzy that I could take as long as 90 minutes to find my
destination and still be assured of plenty of voltage to run my COM
radio, transponder. (By the way, I flew today all the way from
Dallas down to the 50's diner at Brenham in that amount of time, so
90 minutes is a very long time!) To make the condition test really
accurate, one could power up a few more devices and find out if the 4
hour current rating is valid while going to lunch or cleaning up the
hangar. (Not sure I would want to fly for more than 4 hours without
a pit stop and with no alternator.)
Since my certified airplane (1960 vintage Mooney) does not have an
E-bus, I have taken the battery load chart, derated it by 20% to be
really conservative, and posted a synopsis of Current versus Time in
a small chart below my volt-ammeter. (Photo:
http://tinyurl.com/38tpwn ) If I suffer a generator failure, I can
switch the meter to Amps, turn off devices I don't need, look up the
time I should have for that current on the chart, and start my
stopwatch. It's not as quick and efficient as an E-bus, but it
should get the job done without causing me to break a sweat, and it
doesn't require an STC or a 337 or any other governmental
bureaucratic safety-inhibiting nonsense. It's doubtful any of the
authors of dark and stormy night stories ever went to the trouble to
create a little chart like that. It takes 10 minutes to do.
I also keep in my flight bag a handheld comm radio with a
rechargeable battery pack and a separate alkaline battery pack.
Zeftronics makes a line of modern voltage regulators to replace the
horrible Delco Remy mechanical gizmo from the 60's with a nice device
that features OV and LV lights as well as Overvoltage protection
using an external relay.
Those are just some of the things I have discovered that hopefully
some of the certified people on this list might find useful.
Dave Morris
www.N6030X.com
At 05:46 PM 3/17/2007, you wrote:
> If I owned a certified machine, I would endeavor to
> (1) add ACTIVE NOTIFICATION OF LOW VOLTAGE. (2)
> install and MAINTAIN an RG battery. (3) Modify
> the architecture to turn the avionics bus into an
> E-BUS. (4) When an if the stock alternator craps,
> I'd get a modern automotive adaptation in place.
>
> These simple changes alone would elevate the spam
> can's SYSTEM reliability by a quantum jump. Implementation
> of an e-bus/bat-maintenance protocol makes the vast
> majority of demonstrated concerns go away. Virtually
> every dark-n-stormy night story I've read that concerned
> electrical systems would never had been written had
> the owner-operators of the subject airplanes availed
> themselves of the knowledge and understanding offered
> to you here on this List.
Message 7
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Bob,
It looks (in the wiring diagram) like the starter contactor diode is
internal. Do I need to purchase another contactor with the diode across
the coil or is there a way to add it externally?
Re the alternator not charging. This is a new engine with first starts
so there's no history--hasn't worked from the beginning. I've
re-checked the wiring and it seems to be connected properly but . . .
still not showing a charge.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Wednesday, March 14, 2007 12:45 PM
Subject: RE: AeroElectric-List: Popped CB
<nuckollsr@cox.net>
At 11:20 AM 3/14/2007 -0400, you wrote:
>
>Bob,
>The CB popped when I released the starter contactor (switch with key).
>Master was on BAT & ALT. I tried starting with just BAT & it did not
>pop. It did not pop when I switched to Alt after starting with Bat
>only.
>
>I noticed this time I'm not getting a charge from Alt (verified master
>switch on Alt) at 2400RPM.
Hmmm . . . this needs troubleshooting. Has it worked
in the past?
>I overlooked the diode on the starter contactor so, no, I do not have
>one. Maybe that's the problem???
I'll bet on it. But in any case, starting with the alternator
off is a reasonable procedure too. However, your starter
switch will appreciate having the diode added.
Bob . . .
Message 8
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| Subject: | Non coax to BNC connector. |
Have an Electronics International Capacitive Fuel Gauge for Van's capacitive
senders in my RV-6 fuel tanks. Van's sender kit included female BNC
connectors that are pro-sealed right into the tank. Fuel gauge comes with
harness and two sets of short cables (that include converter circuit cards
molded into them) that takes two wires out of the tank and converts to three
wires for connection to the gauge. The converter cable assemblies have two
AWG20 wires going in and three AWG20 wires that connect to the gauge. I
need to somehow hook the two AWG20 wires to a BNC male connector to mate
with the connector on each tank. The center conductor is a no brainer but
what would be the best way to hook the other wire to what would normally be
the shield of the coax crimped under the cylindrical cover (on the outside
of the coax)? Thanks.
Dean
RV-6A N197DM
Last details before inspection.
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