Today's Message Index:
----------------------
1. 11:41 AM - Re: Electrical System Schematic Review (jonlaury)
2. 01:10 PM - Re: Re: Electrical System Schematic Review (Robert L. Nuckolls, III)
3. 08:12 PM - Low Voltage Warning Light (Don)
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: | Re: Electrical System Schematic Review |
Bob and Joe,
OK, I got kind of buried in the details and my goal became to build an absolutely
bullet- proof redundant electrical system rather than one that is practical
for my purposes. Also at work was a lack of confidence in my understanding of
electrical theory and principle and a visceral notion that electricity is a
mysterious, unpredictable serpent , so to compensate for that and to gain a level
of comfort, I chose to just overbuild its cage.
After both of your responses and re-reading the purpose of Ebus, I see that somewhere
along the development of my system, I came to view the Main bus as something
that might fail and misconceived the Ebus as a back up. After discussion
offline with a Glasair III builder (using Z-12) and Bobs suggestion to stand
back and review the big picture I can now reason that the MB has switches and
fuses for every circuit and that my apprehension that, despite proper construction,
it could crash altogether is simply unsupportable.
With the above in mind, Z-12 now seems elegantly appropriate for my needs and I
will eliminate the Ebus altogether, per Bobs suggestion. The one feature of my
drawn architecture that deviates from Z-12 is the SB Alt B lead landing on the
battery side of the MB contactor. I perceive that this will allow me to use
the Generic Ford Regulator over the B&C SB-1 and eliminate the MB contactor as
a single point of failure in the charging circuit. I seem to remember Bob recommending
a mechanical lock out of the SB alt, if not using the SB-1??
Z-12 w- SB ALT contactor is attached.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=306153#306153
Attachments:
http://forums.matronics.com//files/z12_w_sb_alt_contactor_208.pdf
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: Electrical System Schematic Review |
At 01:37 PM 7/24/2010, you wrote:
>
>Bob and Joe,
>
>OK, I got kind of buried in the details and my
>goal became to build an absolutely bullet- proof
>redundant electrical system rather than one that is practical for my purposes.
I hope you don't feel that this has been a "wasted" exercise.
The elegant solution is like a fine wine. Not only are the
choices of simple-ideas large and varied, the time that it
takes to hypothesize, assemble and consider the results doesn't
happen like magic. In fact, one must be wary of new designs
offered by anyone in any discipline until that caution is
displaced by understanding.
I'm going into production on the 9024 series devices after
perhaps a year of mulling over the options . . . and I've
been doing this for a long time. The B&C starter was over
6 years in development. I can probably recall many more
examples of how the roots of many products run deep in
man-years of preparation.
>With the above in mind, Z-12 now seems elegantly
>appropriate for my needs and I will eliminate
>the Ebus altogether, per Bobs suggestion. The
>one feature of my drawn architecture that
>deviates from Z-12 is the SB Alt B lead landing
>on the battery side of the MB contactor. I
>perceive that this will allow me to use the
>Generic Ford Regulator over the B&C SB-1 and
>eliminate the MB contactor as a single point of
>failure in the charging circuit. I seem to
>remember Bob recommending a mechanical lock out
>of the SB alt, if not using the SB-1??
Not sure where that might have come from. Note that Z-12
as published is illustrative and demonstrative of a minimalist
approach to adding robust aux alternators to a TC aircraft. Note
that unlike the rest of the z-figures, Z-12 shows breakers on
the bus as opposed to fuse blocks. A Z-12 for new design where
crowbar ov protection is proposed might lean toward fuse blocks
but take both B-leads to fat wires under the cowl through
current limiters. Of course, the field supply leads still need
breakers . . . run a 20 pair of 18AWG feeders protected with
22AWG fusible links to their respective alternator control switches.
This might be a Z11-1/2 where you simply add a second alternator
that needs only one more switch (field supply) on the panel.
Eliminate the e-bus. Run ALL electrically dependent engine
loads from the battery bus.
In further "stirring of simple-ideas" I note that another
feature of the e-bus is a plan-b for dealing with a
battery contactor failure. These are rare and can
probably become still more rare if fitted with
power a management module to reduce operating temperature.
Even so, we could consider tying your aux alternator b-lead
to the battery side of the contactor with a Schottky diode
to isolate the always-hot, fat wire between battery and
alternator. In this case, you'd also need to power the
aux alternator field from the battery bus. This variant
would cover the failed-contactor scenario.
Let me ponder this some more. Take a whack at implementing
this using your current CAD skills. By the way, good work
with the CAD drawings.
I'm pretty certain that we're boiling the options down
toward the essence of an elegant solution. The
40A aux alternator offers a Z-12 like architecture
that accommodates more demanding engine support
loads.
Bob . . .
>Z-12 w- SB ALT contactor is attached.
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=306153#306153
>
>
>Attachments:
>
>http://forums.matronics.com//files/z12_w_sb_alt_contactor_208.pdf
>
>
>Checked by AVG - www.avg.com
>- Release Date: 07/24/10 01:36:00
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: | Low Voltage Warning Light |
Bob,
I am using an LR3 voltage regulator and a B&C 60 A alternator. Is it
acceptable to change out the supplied warning light for a red 12 volt led?
It would be in my direct line of sight so I do not think the lack of
blinking would be an issue. That is if the blinking is a function of the
light and not the regulator. Please let me know if there would be problems
with using an led and if it would blink. TIA Don VS
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! --
|