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nuckolls.bob(at)aeroelect Guest
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Posted: Sun Dec 22, 2019 6:45 pm Post subject: The next generation of Z12 |
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At 10:33 PM 12/21/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: Rick Beebe <rick(at)beebe.org>
On 12/20/2019 7:15 PM, user9253 wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com>
So as mentioned in my post of a few mintues
ago, I think I'm going to revise Z-12 to (1)
remove the Endurance Bus and (2) replace the
standby regulator with something simple and
cheap. | > Great idea Bob. Simpler is better.
Quote: | Many VFR sport planes do not even need a standby alternator.
Now if we could just convince builders to NOT install an avionics switch.
--------
Joe Gores |
I'm sold on both counts. I'm turning my traditional 6-pack VFR GlaStar into an all-glass IFR plane and I'm wiring it using Z-12 with no endurance bus and no avionics master. I repurposed its hole for the pitot heat switch. |
We've been pondering a relatively new
phenomenon that may well justify keeping
the 'special' bus . . .
The e-bus came about because it seemed
elegant to have a plan-b for battery
only operations that minimize loads on
the battery while eliminating contactor
loads on an SD8. Obviously, 'minimizing
loads' in a dual-alternator system
has little or no value assuming the
standby alternator will carry all
of the plan-b loads.
If the s/b alternator in Z-12 meets
those requirements, then we're no longer
concerned with the ENDURANCE bus.
In recent years, we've seen a new constellation
of flight instruments and avionics with greatly
EXPANDED functionality but with LOWER energy
demands from ship's power . . . except . . .
The critters like to 'reboot' if the bus
voltage is depressed below some value . . .
a condition generally limited to a few tens
of milliseconds during starter motor inrush.
The new condition has been discussed and
numerous solutions proposed and some
tried. Some systems feature a small,
support battery wired to support vulnerable
devices during engine cranking. A variety
of control protocols have been considered
The simplest and most elegant solution seems
to be the inclusion of a dc/dc up-converter
set up for an output of 14 or so volts. This
device is diode-ored to supply power to the
'brown out bus' a few milliseconds before
the starter contactor closes . . . and is
kept in the loop as long as the starter button
is engaged.
[img]cid:.0[/img]
A excerpt schematic shown here. Obviously, this
requires a more robust starter push-button. Two
diodes in a bridge rectifier provide the diode-or
function for powering from either the MAIN bus
or the brown-out booster.
Since the dedicated special function bus exists,
the builder COULD carry the legacy alternate
alternate feed path from the battery onto the
brown-out bus.
Of all the philosophies we've discussed, this on
seems the most elegant. I'm going to incorporate
it into the next revision to Z12.
To recap:
(1) the need for an Endurance Bus goes away
'cause the second source of engine driven
power is sufficiently robust to manage
most necessary loads during loss of main
alternator.
(2) The legacy auto switching feature for the standby
alternator serves no practical purpose. In
fact, there's no reason that the s/b alternator
couldn't be paired with the least expensive
of regulators. (a) the probability of ever
needing it is low. (b) all of the warning and
adjustability features of a primo alternator
controller will not add to the utility of
having the high-energy source available
for perhaps a few hours after loss of main
alternator.
(3) For airplanes fitted with brown-out sensitive
appliances, an independently support bus
driven with solid state voltage boost offers
compact, low cost of ownership and maintenance
free alternatives to any form of battery.
Bob . . .
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user9253
Joined: 28 Mar 2008 Posts: 1921 Location: Riley TWP Michigan
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Posted: Sun Dec 22, 2019 7:24 pm Post subject: Re: The next generation of Z12 |
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The relay needs to be electrically interlocked with the start button to
prevent the DC-DC booster from supplying current to the starter motor.
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donvansanten(at)gmail.com Guest
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Posted: Sun Dec 22, 2019 7:47 pm Post subject: The next generation of Z12 |
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The TCW stand by battery, a little expensive, does the same thing with no other system changes. It also is able to keep two Advanced Flight EFIS'S alive for 30 plus minutes in case of contactor issues.
On Sun, Dec 22, 2019, 19:30 user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>
The relay needs to be electrically interlocked with the start button to
prevent the DC-DC booster from supplying current to the starter motor.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=493942#493942
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roughleg(at)gmail.com Guest
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Posted: Sun Dec 22, 2019 7:48 pm Post subject: The next generation of Z12 |
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Bob, do you have a part number for the brown-out booster? I'm curious about its characteristics (e.g., what's the highest voltage it might produce if the brown-out isn't so bad). Also, if the bus depression is a few tens of milliseconds, might a big hefty capacitor do the trick (charged from the main bus, not the starter feed)?
On Sun, Dec 22, 2019 at 7:52 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
Quote: | At 10:33 PM 12/21/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: Rick Beebe <rick(at)beebe.org (rick(at)beebe.org)>
On 12/20/2019 7:15 PM, user9253 wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>
So as mentioned in my post of a few mintues
ago, I think I'm going to revise Z-12 to (1)
remove the Endurance Bus and (2) replace the
standby regulator with something simple and
cheap. |
|
Quote: | > Great idea Bob. Simpler is better.
Quote: | Many VFR sport planes do not even need a standby alternator.
Now if we could just convince builders to NOT install an avionics switch.
--------
Joe Gores |
I'm sold on both counts. I'm turning my traditional 6-pack VFR GlaStar into an all-glass IFR plane and I'm wiring it using Z-12 with no endurance bus and no avionics master. I repurposed its hole for the pitot heat switch. |
 We've been pondering a relatively new
 phenomenon that may well justify keeping
 the 'special' bus . . .
 The e-bus came about because it seemed
 elegant to have a plan-b for battery
 only operations that minimize loads on
 the battery while eliminating contactor
 loads on an SD8. Obviously, 'minimizing
 loads' in a dual-alternator system
 has little or no value assuming the
 standby alternator will carry all
 of the plan-b loads.
 If the s/b alternator in Z-12 meets
 those requirements, then we're no longer
 concerned with the ENDURANCE bus.
 In recent years, we've seen a new constellation
 of flight instruments and avionics with greatly
 EXPANDED functionality but with LOWER energy
 demands from ship's power . . . except . . .
 The critters like to 'reboot' if the bus
 voltage is depressed below some value . . .
 a condition generally limited to a few tens
 of milliseconds during starter motor inrush.
 The new condition has been discussed and
 numerous solutions proposed and some
 tried. Some systems feature a small,
 support battery wired to support vulnerable
 devices during engine cranking. A variety
 of control protocols have been considered
 The simplest and most elegant solution seems
 to be the inclusion of a dc/dc up-converter
 set up for an output of 14 or so volts. This
 device is diode-ored to supply power to the
 'brown out bus' a few milliseconds before
 the starter contactor closes . . . and is
 kept in the loop as long as the starter button
 is engaged.
[img]cid:16f30d66347326eec31[/img]
 A excerpt schematic shown here. Obviously, this
 requires a more robust starter push-button. Two
 diodes in a bridge rectifier provide the diode-or
 function for powering from either the MAIN bus
 or the brown-out booster.
 Since the dedicated special function bus exists,
 the builder COULD carry the legacy alternate
 alternate feed path from the battery onto the
 brown-out bus.
 Of all the philosophies we've discussed, this on
 seems the most elegant. I'm going to incorporate
 it into the next revision to Z12.
 To recap:
 (1) the need for an Endurance Bus goes away
     'cause the second source of engine driven
     power is sufficiently robust to manage
     most necessary loads during loss of main
     alternator.
 (2) The legacy auto switching feature for the standby
     alternator serves no practical purpose. In
     fact, there's no reason that the s/b alternator
     couldn't be paired with the least expensive
     of regulators. (a) the probability of ever
     needing it is low. (b) all of the warning and
     adjustability features of a primo alternator
     controller will not add to the utility of
     having the high-energy source available
     for perhaps a few hours after loss of main
     alternator.
 (3) For airplanes fitted with brown-out sensitive
     appliances, an independently support bus
     driven with solid state voltage boost offers
     compact, low cost of ownership and maintenance
     free alternatives to any form of battery.
 Bob . . .
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cluros(at)gmail.com Guest
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Posted: Sun Dec 22, 2019 7:58 pm Post subject: The next generation of Z12 |
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I completely agree with (1), (2), and (3) Bob. All would be an improvement to our current systems.
As an aside, I have not had any problems with EFIS systems rebooting during engine start. It seems that Dynon, GRT, Garmin, all now take care of this internally since they are all expected to keep working during engine start since they are the engine instruments. With IFR aircraft though, it is nice to be able to program the GNC before engine start, and I've lost the programming a few times during engine start. Very frustrating, especially since even saving the flight plan doesn't yield useful results as many departures and arrivals will not load properly from a saved flight plan. On these aircraft brown-out protection for the GNCs would be very helpful.
Also of possible interest, on the way to Oshkosh last year the backup battery for our PFD starting giving error messages. The builder commented that we were down to only 3 sources of power for it (2 alternators and the ship's battery). To test the theory I switched to the backup alternator (SD- and it was completely dead, which I said wasn't possible. At destination the builder had a look under the panel and confirmed that a wire had vibrated loose.
On Sun, Dec 22, 2019 at 6:52 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
Quote: | At 10:33 PM 12/21/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: Rick Beebe <rick(at)beebe.org (rick(at)beebe.org)>
On 12/20/2019 7:15 PM, user9253 wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>
So as mentioned in my post of a few mintues
ago, I think I'm going to revise Z-12 to (1)
remove the Endurance Bus and (2) replace the
standby regulator with something simple and
cheap. |
|
Quote: | > Great idea Bob. Simpler is better.
Quote: | Many VFR sport planes do not even need a standby alternator.
Now if we could just convince builders to NOT install an avionics switch.
--------
Joe Gores |
I'm sold on both counts. I'm turning my traditional 6-pack VFR GlaStar into an all-glass IFR plane and I'm wiring it using Z-12 with no endurance bus and no avionics master. I repurposed its hole for the pitot heat switch. |
 We've been pondering a relatively new
 phenomenon that may well justify keeping
 the 'special' bus . . .
 The e-bus came about because it seemed
 elegant to have a plan-b for battery
 only operations that minimize loads on
 the battery while eliminating contactor
 loads on an SD8. Obviously, 'minimizing
 loads' in a dual-alternator system
 has little or no value assuming the
 standby alternator will carry all
 of the plan-b loads.
 If the s/b alternator in Z-12 meets
 those requirements, then we're no longer
 concerned with the ENDURANCE bus.
 In recent years, we've seen a new constellation
 of flight instruments and avionics with greatly
 EXPANDED functionality but with LOWER energy
 demands from ship's power . . . except . . .
 The critters like to 'reboot' if the bus
 voltage is depressed below some value . . .
 a condition generally limited to a few tens
 of milliseconds during starter motor inrush.
 The new condition has been discussed and
 numerous solutions proposed and some
 tried. Some systems feature a small,
 support battery wired to support vulnerable
 devices during engine cranking. A variety
 of control protocols have been considered
 The simplest and most elegant solution seems
 to be the inclusion of a dc/dc up-converter
 set up for an output of 14 or so volts. This
 device is diode-ored to supply power to the
 'brown out bus' a few milliseconds before
 the starter contactor closes . . . and is
 kept in the loop as long as the starter button
 is engaged.
[img]cid:16f30dbcc88326eec31[/img]
 A excerpt schematic shown here. Obviously, this
 requires a more robust starter push-button. Two
 diodes in a bridge rectifier provide the diode-or
 function for powering from either the MAIN bus
 or the brown-out booster.
 Since the dedicated special function bus exists,
 the builder COULD carry the legacy alternate
 alternate feed path from the battery onto the
 brown-out bus.
 Of all the philosophies we've discussed, this on
 seems the most elegant. I'm going to incorporate
 it into the next revision to Z12.
 To recap:
 (1) the need for an Endurance Bus goes away
     'cause the second source of engine driven
     power is sufficiently robust to manage
     most necessary loads during loss of main
     alternator.
 (2) The legacy auto switching feature for the standby
     alternator serves no practical purpose. In
     fact, there's no reason that the s/b alternator
     couldn't be paired with the least expensive
     of regulators. (a) the probability of ever
     needing it is low. (b) all of the warning and
     adjustability features of a primo alternator
     controller will not add to the utility of
     having the high-energy source available
     for perhaps a few hours after loss of main
     alternator.
 (3) For airplanes fitted with brown-out sensitive
     appliances, an independently support bus
     driven with solid state voltage boost offers
     compact, low cost of ownership and maintenance
     free alternatives to any form of battery.
 Bob . . .
|
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nuckolls.bob(at)aeroelect Guest
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Posted: Mon Dec 23, 2019 8:11 am Post subject: The next generation of Z12 |
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At 09:43 PM 12/22/2019, you wrote:
Quote: | Bob, do you have a part number for the brown-out booster? I'm curious about its characteristics (e.g., what's the highest voltage it might produce if the brown-out isn't so bad). Also, if the bus depression is a few tens of milliseconds, might a big hefty capacitor do the trick (charged from the main bus, not the starter feed)?
|
It's an off-the-shelf product off eBay, banggood, amazon.
Sized to the task. It's an adjustable, set-and-forget,
step up power supply. Here's an exemplar device.
https://tinyurl.com/sf8wwob
Note: lets not run out and buy one of THESE
devices before we do some bench testing. . .
from the constellation of candidates, there
WILL be an entirely suitable device but I
can't tell you yet that it's THIS one . . .
Capacitors have been used successfully in
cases where but brownout bus is lightly
loaded . . . but some builder's plans
called for more snort. Further, the capacitor
boost device called for significant beat-n-
bash on the bench to assemble a number of
components from Digikey et. als.
The upside of the boost-converters is that
they are very nearly plug-n-play and
come in a variety of sizes wherein virtually
all brown-out protections can be addressed.
Bob . . .
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nuckolls.bob(at)aeroelect Guest
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Posted: Mon Dec 23, 2019 8:18 am Post subject: The next generation of Z12 |
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At 09:57 PM 12/22/2019, you wrote:
Quote: | I completely agree with (1), (2), and (3) Bob. All would be an improvement to our current systems.
As an aside, I have not had any problems with EFIS systems rebooting during engine start. It seems that Dynon, GRT, Garmin, all now take care of this internally since they are all expected to keep working during engine start since they are the engine instruments. With IFR aircraft though, it is nice to be able to program the GNC before engine start, and I've lost the programming a few times during engine start. Very frustrating, especially since even saving the flight plan doesn't yield useful results as many departures and arrivals will not load properly from a saved flight plan. On these aircraft brown-out protection for the GNCs would be very helpful. |
Good input. I'm pleased that the OEM's may
be stepping up to the WHOLE spirit and intent
of DO160 qualification testing.
We've been thinking along similar concerns.
The alternate feed for the BO BUS will stay
in place but labeled CLEARANCE DELIVERY.
It will power up the BO BUS with the rest
of the airplane stone cold. This will facilitate
preflight clearance delivery, smart-whizzy
programming, etc. while protecting any device
vulnerable to start-up brown-out.
I will have a preliminary update to Z12 to share
soon. Just noticed that its last update was
14 years ago. (A) time flies when you're having
fun and (B) things change . . . quite often
driven by the natural evolution of products
and processes.
Quote: | Also of possible interest, on the way to Oshkosh last year the backup battery for our PFD starting giving error messages. The builder commented that we were down to only 3 sources of power for it (2 alternators and the ship's battery). To test the theory I switched to the backup alternator (SD- and it was completely dead, which I said wasn't possible. At destination the builder had a look under the panel and confirmed that a wire had vibrated loose. |
Which is why one has preflight check lists
or did he state that the alternator passed
pre-flight and the break occurred on THIS
leg of the flight?
Bob . . .
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nuckolls.bob(at)aeroelect Guest
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Posted: Mon Dec 23, 2019 8:21 am Post subject: The next generation of Z12 |
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At 09:24 PM 12/22/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com>
The relay needs to be electrically interlocked with the start button to
prevent the DC-DC booster from supplying current to the starter motor.
|
You lost me . . . how would that happen?
Bob . . .
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cluros(at)gmail.com Guest
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Posted: Mon Dec 23, 2019 8:43 am Post subject: The next generation of Z12 |
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It's a day VFR only ship so after regular checks during Phase 1 I basically forgot about it. It should be added to the checklist.
On Mon, Dec 23, 2019, 08:23 Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
Quote: | At 09:57 PM 12/22/2019, you wrote:
Quote: | I completely agree with (1), (2), and (3) Bob. All would be an improvement to our current systems.
As an aside, I have not had any problems with EFIS systems rebooting during engine start. It seems that Dynon, GRT, Garmin, all now take care of this internally since they are all expected to keep working during engine start since they are the engine instruments. With IFR aircraft though, it is nice to be able to program the GNC before engine start, and I've lost the programming a few times during engine start. Very frustrating, especially since even saving the flight plan doesn't yield useful results as many departures and arrivals will not load properly from a saved flight plan. On these aircraft brown-out protection for the GNCs would be very helpful. |
  Good input. I'm pleased that the OEM's may
  be stepping up to the WHOLE spirit and intent
  of DO160 qualification testing.
  We've been thinking along similar concerns.
  The alternate feed for the BO BUS will stay
  in place but labeled CLEARANCE DELIVERY.
  It will power up the BO BUS with the rest
  of the airplane stone cold. This will facilitate
  preflight clearance delivery, smart-whizzy
  programming, etc. while protecting any device
  vulnerable to start-up brown-out.
Â
  I will have a preliminary update to Z12 to share
  soon. Just noticed that its last update was
  14 years ago. (A) time flies when you're having
  fun and (B) things change . . . quite often
  driven by the natural evolution of products
  and processes.
Quote: | Also of possible interest, on the way to Oshkosh last year the backup battery for our PFD starting giving error messages. The builder commented that we were down to only 3 sources of power for it (2 alternators and the ship's battery). To test the theory I switched to the backup alternator (SD- and it was completely dead, which I said wasn't possible. At destination the builder had a look under the panel and confirmed that a wire had vibrated loose. |
  Which is why one has preflight check lists
  or did he state that the alternator passed
  pre-flight and the break occurred on THIS
  leg of the flight?
 Bob . . .
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user9253
Joined: 28 Mar 2008 Posts: 1921 Location: Riley TWP Michigan
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Posted: Mon Dec 23, 2019 8:47 am Post subject: Re: The next generation of Z12 |
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Quote: | You lost me . . . how would that happen? |
If the pilot inadvertently leaves the brownout relay switch turned on, then the
relay contacts provide a current path between the DC-DC booster and starter
motor via diode, brownout bus, relay contacts, main battery bus, battery,
battery contactor, starter contactor, starter motor, not to mention other
aircraft loads. To make the circuit foolproof, the relay coil circuit should be
wired in series with the normally closed half of a DPDT start push button.
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nuckolls.bob(at)aeroelect Guest
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Posted: Mon Dec 23, 2019 9:01 am Post subject: The next generation of Z12 |
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At 09:24 PM 12/22/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com>
The relay needs to be electrically interlocked with the start button to
prevent the DC-DC booster from supplying current to the starter motor.
|
You lost me . . . how would that happen?
Bob . . .
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nuckolls.bob(at)aeroelect Guest
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Posted: Mon Dec 23, 2019 9:18 am Post subject: The next generation of Z12 |
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At 10:47 AM 12/23/2019, you wrote:
Quote: | --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com>
> You lost me . . . how would that happen?
If the pilot inadvertently leaves the brownout relay switch turned on, then the
relay contacts provide a current path between the DC-DC booster and starter
motor via diode, brownout bus, relay contacts, main battery bus, battery,
battery contactor, starter contactor, starter motor, not to mention other
aircraft loads. To make the circuit foolproof, the relay coil circuit should be
wired in series with the normally closed half of a DPDT start push button.
--------
Joe Gores
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Good catch . . .
I've published the P1 edition of Rev N to Z-12
at:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z12NP1.pdf
Per Joe's catch, I've routed the brownout booster
power through normally closed contacts of the
CLEARANCE DELIVERY relay. So if the switch is
inadvertently left closed during start, there will
be no back-feed of boost power to the rest of the
system. The worst thing that happens is that
some electro-whizzies may reboot . . .
Got to quit doing 'fun stuff' and get onto
Xmas preparations. With our respective, extended
families the next week or so will be really busy.
Hope you all are going to have as much fun
as I am!
Merry Christmas . . .
Bob . . .
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