Today's Message Index:
----------------------
1. 06:18 AM - Scan Mar 11, 2020 at 9.05 AM (Bill Boyd)
2. 06:48 AM - Re: Re: Two Radios to One Intercom (Pat Little)
3. 07:42 AM - Re: Scan Mar 11, 2020 at 9.05 AM (user9253)
4. 08:49 AM - Re: Scan Mar 11, 2020 at 9.05 AM (Robert L. Nuckolls, III)
5. 09:58 AM - Re: Scan Mar 11, 2020 at 9.05 AM (Bill Boyd)
6. 12:36 PM - Re: Scan Mar 11, 2020 at 9.05 AM (Robert L. Nuckolls, III)
7. 01:10 PM - Re: Scan Mar 11, 2020 at 9.05 AM (Robert L. Nuckolls, III)
8. 01:12 PM - Re: Scan Mar 11, 2020 at 9.05 AM (Robert L. Nuckolls, III)
9. 04:31 PM - Two coms mic switching (cofford)
Message 1
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| Subject: | Scan Mar 11, 2020 at 9.05 AM |
Would appreciate if y=99all could look this Z-12 variant over - specif
ically for correct implementation of two B&C regulators in automatic switch-
over configuration. TJ at the factory will do the same but is presently desi
gning a new B&C regulator product and might take awhile. I=99m in some
what urgent mode to get my panel build underway. Advanced Flight is already a
sking for design approvals to commence work for my panel. Appreciate a secon
d set of eyes on this DC power scheme before things get too far along.
Note: Bob has already blessed the sharing of an ampere shunt by the two alte
rnators.
-Bill Boyd
Created with Scanner Pro
Sent from my iPhone
Message 2
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| Subject: | Re: Two Radios to One Intercom |
Here is an article on audio mixer circuits. The solutions presented in it
involve use of an op-amp, which makes the circuit a little more
complicated, but offers advantages in better gain and reduced crosstalk.
https://sound-au.com/articles/audio-mixing.htm
I'm building a mixer for my plane to combine "aux" input (2-channel stereo
music, to be mixed to mono) and the alert tone from my EMS into the aux
input of my VHF COM radio. This is 3 inputs rather than the two you are
looking at, but the principle is the same. Here's the diagram from the
article that I plan on using.
[image: image.png]
Hope this helps.
Pat
On Tue, Mar 10, 2020 at 1:29 PM user9253 <fransew@gmail.com> wrote:
>
> Found this drawing someplace.
>
> --------
> Joe Gores
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=495222#495222
>
>
> Attachments:
>
> http://forums.matronics.com//files/audio_combine_160.jpg
>
>
Message 3
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
The drawing is very difficult to read because it is hard to tell
if the lines are part of the graph paper or part of the circuit.
Shunts have been known to fail. One shunt is a single point of failure.
Fuses cost less, weigh less, and are easier to replace than electronic circuit
breakers.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495228#495228
Message 4
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
At 08:15 AM 3/11/2020, you wrote:
>Would appreciate if y=99all could look this Z-12
>variant over - specifically for correct
>implementation of two B&C regulators in
>automatic switch-over configuration. TJ at the
>factory will do the same but is presently
>designing a new B&C regulator product and might
>take awhile. I=99m in somewhat urgent mode to
>get my panel build underway. Advanced Flight is
>already asking for design approvals to commence
>work for my panel. Appreciate a second set of
>eyes on this DC power scheme before things get too far along.
>
>Note: Bob has already blessed the sharing of an
>ampere shunt by the two alternators.
You can run two alternators through a single HALL EFFECT
sensor but EACH alternator should have it's own, dedicated
b-lead and appropriate protection.
The single shunt configuration shown is NOT recommended.
Why the auto switch-over? The aux alternator is a standby
device. Probability of being needed is very low. If it
becomes necessary to bring it on line, you have LOTS
of time. If the low voltage warning light comes on,
finish your coffee, fold the map and put it away and
then start flipping the ONE switch needed to make things
right with the universe. Certainly pre-flight the aux
alternator but leave it off until needed for the
few hours or so of continued flight to your intended
destination.
Standby equipment keeps a failure from becoming an emergency.
Failures are rare so it behooves us to craft the
simplest, lightest and least expensive resolution . . .
kinda like keeping a hammer handy to back up your
nail-gun.
Auto switching was a feature included to keep the
flying-fuzz happy for putting the aux alternator
onto TC aircraft. It's a feature that adds complexity,
cost of ownership and but no practical value when
it comes to dealing with main alternator failure.
There no value for including the 'aux altenrator
loaded/overloaded' indicator. You have a means
for READING alternator loads. Your low voltage
warning light tells you to implement plan-b.
You'll have plenty of standard instrumentation
to accomplish what ever load shedding is needed
to bring the bus voltage back up to battery-conservation
levels. All that Gee-Whiz in the SB1 regulator
was for real estate moguls flying around in A36 Bonanzas . . .
well . . . don't need to go there.
I strongly suggest Z12NP1 AS PUBLISHED. Eliminate
the brown-out bus if you have no BO vulnerable
electro-whizzies. What's with the 'ACM ECB BUS'?
What the return on investment? Remember: over the
century plus history of electrical systems in
aircraft, TONS of circuit breakers have gone to
the scrap yard never having been called upon
to do their job. That's TONS of stuff that
burned more fuel, took up more space, reduced
aircraft payload and did little more
than make the Klixon and T.I. stockholders
happy.
What kind of airplane?
2AWG wire is unnecessary except for LONG runs of
fat-wire like on a seaplane or canard pusher.
Bob . . .
Message 5
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
Oh, boy. I must've missed something in our prior list server exchange on
this in January. I will copy and paste that here for reference:
At 11:59 AM 1/22/2020, you wrote:
Thanks for the feedback, Bob.=C3=82 =C3=82
I have purchased=C3=82 and installed both the LR3C and the SB1B (I think th
ose
are the part #'s) external regulators from B&C.=C3=82 As you know, these c
ome
pre-set for 14.4 and 13.0 V respectively and (so I thought) were intended
to be online simultaneously at these two voltages so that the switchover to
the standby alternator was automatic and required no pilot action.
Yup, this was a feature that targeted
the heavy-singles market and warmed
cockles in the hearts of most bureaucratic
worry-specialists. IMHO, entirely unnecessary
in the OBAM aviation market . . .
=C3=82 Presumably the immediate drop in bus voltage from 14.4 to 13 would
be
sensed and alerted in the EFIS software.
The SB1B comes with an 'ALTERNATOR LOADED'
annunciator which offers timely notification
of main alternator failure as will any EFIS
alarm set to alert for a bus votlage below
the SB1 setpoint.
=C3=82 Please advise if this is not the correct implementation philosophy
of
this standby regulator in tandem with the LR3C, and why it is viewed as
more complex/costly to implement (except the regulator vs the Ford unit.)
Okay, if you're already down that road, then
my prior argument isn't useful. Smoke ahead . . .
it works as advertised.
I assume=C3=82 that if sharing a Hall sensor is permissible it is also perm
itted
to share a 60A shunt.
This is a 'real' shunt . . . not a hall-effect
sensor? Yes, you can tie both b-leads to the
anti-battery end of the shunt.
Bob . . .
To the other questions, I have engaged Advanced Flight to build one of
their Advanced Quick Panels for me, and those are based on their Advanced
Control Module just as others sometimes build around an Approach Fast Stack
hub or a Vertical Power ECB box. I discussed getting a legacy ACM with
fuses from Rob Hickman's inventory, and also having him wire a panel
without the ACM as a hub and using acres of breakers or the modular fuse
block bus approach, and the ACM with ECB's won the day. My purse, my
calendar - my call.
The airplane is an RV-10 with 17 feet of fat wire to the starter spinning
an IO-540. The 2AWG seems appropriate to me.
The shunt, alternators and regulators are items I've already purchased and
installed in my airframe. I'm here to make sure I'm about to wire the
regulators correctly for their intended use.
-Bill
On Wed, Mar 11, 2020 at 11:54 AM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 08:15 AM 3/11/2020, you wrote:
>
> Would appreciate if y=C3=A2=82=AC=84=A2all could look this Z-12 var
iant over -
> specifically for correct implementation of two B&C regulators in automati
c
> switch-over configuration. TJ at the factory will do the same but is
> presently designing a new B&C regulator product and might take awhile.
> I=C3=A2=82=AC=84=A2m in somewhat urgent mode to get my panel build
underway. Advanced
> Flight is already asking for design approvals to commence work for my
> panel. Appreciate a second set of eyes on this DC power scheme before
> things get too far along.
>
> Note: Bob has already blessed the sharing of an ampere shunt by the two
> alternators.
>
>
> You can run two alternators through a single HALL EFFECT
> sensor but EACH alternator should have it's own, dedicated
> b-lead and appropriate protection.
>
> The single shunt configuration shown is NOT recommended.
>
> Why the auto switch-over? The aux alternator is a standby
> device. Probability of being needed is very low. If it
> becomes necessary to bring it on line, you have LOTS
> of time. If the low voltage warning light comes on,
> finish your coffee, fold the map and put it away and
> then start flipping the ONE switch needed to make things
> right with the universe. Certainly pre-flight the aux
> alternator but leave it off until needed for the
> few hours or so of continued flight to your intended
> destination.
>
> Standby equipment keeps a failure from becoming an emergency.
> Failures are rare so it behooves us to craft the
> simplest, lightest and least expensive resolution . . .
> kinda like keeping a hammer handy to back up your
> nail-gun.
>
> Auto switching was a feature included to keep the
> flying-fuzz happy for putting the aux alternator
> onto TC aircraft. It's a feature that adds complexity,
> cost of ownership and but no practical value when
> it comes to dealing with main alternator failure.
>
> There no value for including the 'aux altenrator
> loaded/overloaded' indicator. You have a means
> for READING alternator loads. Your low voltage
> warning light tells you to implement plan-b.
> You'll have plenty of standard instrumentation
> to accomplish what ever load shedding is needed
> to bring the bus voltage back up to battery-conservation
> levels. All that Gee-Whiz in the SB1 regulator
> was for real estate moguls flying around in A36 Bonanzas . . .
> well . . . don't need to go there.
>
> I strongly suggest Z12NP1 AS PUBLISHED. Eliminate
> the brown-out bus if you have no BO vulnerable
> electro-whizzies. What's with the 'ACM ECB BUS'?
> What the return on investment? Remember: over the
> century plus history of electrical systems in
> aircraft, TONS of circuit breakers have gone to
> the scrap yard never having been called upon
> to do their job. That's TONS of stuff that
> burned more fuel, took up more space, reduced
> aircraft payload and did little more
> than make the Klixon and T.I. stockholders
> happy.
>
> What kind of airplane?
>
> 2AWG wire is unnecessary except for LONG runs of
> fat-wire like on a seaplane or canard pusher.
>
> Bob . . .
>
Message 6
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
At 11:55 AM 3/11/2020, you wrote:
>>I assume=C3=82 that if sharing a Hall sensor is
>>permissible it is also permitted to share a 60A shunt.
>
>=C2 This is a 'real' shunt . . . not a hall-effect
>=C2 sensor? Yes, you can tie both b-leads to the
>=C2 anti-battery end of the shunt.
Can't imagine where my head was at with that . . .
Obviously, this causes two alternators to share
a fault protection device at the far end of
the b-lead . . . a failure in one alternator takes
down both alternators.
My bad. I owe you a six-pak . . .
Bob . . .
Message 7
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
>
>
>To the other questions, I have engaged Advanced
>Flight to build one of their Advanced Quick
>Panels for me, and those are based on their
>Advanced Control=C2 Module just as others
>sometimes build around an Approach Fast Stack
>hub or a Vertical Power ECB box.=C2 I discussed
>getting a legacy ACM with fuses from Rob
>Hickman's inventory, and also having him wire a
>panel without the ACM as a hub and using acres
>of breakers or the modular fuse block bus
>approach, and the ACM with ECB's won the
>day.=C2 My purse, my calendar - my call.
>
>The airplane is an RV-10 with 17 feet of fat
>wire to the starter spinning an IO-540.=C2 The 2AWG seems appropriate to
me.=C2 =C2
>
>The shunt, alternators and regulators are items
>I've already purchased and installed in my
>airframe.=C2 I'm here to make sure I'm about to
>wire the regulators correctly for their intended use.=C2
Okay, plan-C:
Put put a limiter in each b-lead with the
limiters as close as practical to the alternator
end of the shunt. Make shortest practical connection
between battery end of shunt and the contactor.
Agreed . . . 2AWG is a better choice for this
distance.
Sorry for the floobydust . . . I didn't recall
our earlier discussions. I think you're good to
go!
Bob . . .
Message 8
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| Subject: | Re: Scan Mar 11, 2020 at 9.05 AM |
>
>
>To the other questions, I have engaged Advanced
>Flight to build one of their Advanced Quick
>Panels for me, and those are based on their
>Advanced Control=C2 Module just as others
>sometimes build around an Approach Fast Stack
>hub or a Vertical Power ECB box.=C2 I discussed
>getting a legacy ACM with fuses from Rob
>Hickman's inventory, and also having him wire a
>panel without the ACM as a hub and using acres
>of breakers or the modular fuse block bus
>approach, and the ACM with ECB's won the
>day.=C2 My purse, my calendar - my call.
>
>The airplane is an RV-10 with 17 feet of fat
>wire to the starter spinning an IO-540.=C2 The 2AWG seems appropriate to
me.=C2 =C2
>
>The shunt, alternators and regulators are items
>I've already purchased and installed in my
>airframe.=C2 I'm here to make sure I'm about to
>wire the regulators correctly for their intended use.=C2
Okay, plan-C:
Put put a limiter in each b-lead with the
limiters as close as practical to the alternator
end of the shunt. Make shortest practical connection
between battery end of shunt and the contactor.
Agreed . . . 2AWG is a better choice for this
distance.
Sorry for the floobydust . . . I didn't recall
our earlier discussions. I think you're good to
go!
Bob . . .
Message 9
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| Subject: | Two coms mic switching |
Hello all,
I'm sure this has been answered before, but I'm planning to use two com radios
without an audio panel, so I need to switch the mic input. My current plan is
to use two PTT switches on the stick, and tie the COM 2 PTT to a relay to switch
the mic automatically. Does only the "MIC HIGH" side need to be switched,
or do I need to switch the "MIC LOW" side as well? I think "MIC LOW" is just
a ground reference for the mic input, but I'm looking for the lowest noise solution.
Thanks,
Casey
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495242#495242
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