Today's Message Index:
----------------------
1. 04:42 AM - Re: Re: voltage monitor (bob noffs)
2. 09:00 AM - Re: voltage monitor (bobnoffs)
3. 09:47 AM - Re: field current supplied from B lead instead of from main bus (Robert L. Nuckolls, III)
4. 10:26 AM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
5. 10:45 AM - Re: Re: Can radials of home made ground plane be tapered? (Robert L. Nuckolls, III)
6. 11:12 AM - Re: voltage monitor (bobnoffs)
7. 11:29 AM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
8. 11:48 AM - Re: field current supplied from B lead instead of from main bu (johnbright)
9. 12:09 PM - Re: Re: voltage monitor (Charlie England)
10. 12:10 PM - Re: field current supplied from B lead instead of from main bus (user9253)
11. 12:10 PM - Li-Ion versus LiFePO4 (Robert L. Nuckolls, III)
12. 12:23 PM - Re: Re: voltage monitor (Charles Kuss)
13. 02:21 PM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
14. 02:33 PM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
15. 02:53 PM - Re: voltage monitor (bobnoffs)
16. 03:06 PM - Re: ADS-B and Transponder antenna design... (andymeyer)
17. 03:17 PM - Re: Re: voltage monitor (Charlie England)
18. 03:24 PM - Re: Re: ADS-B and Transponder antenna design... (Charlie England)
19. 03:33 PM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
20. 03:51 PM - Re: Re: voltage monitor (Ken Ryan)
Message 1
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| Subject: | Re: voltage monitor |
since my first post perihelion design has let me know that their idiot
light can be made to any high/low settings. pretty slick fix. 2 leads [i
assume] and it all fits in a .55'' panel hole. light can be ordered
flashing or steady.
On Sat, Oct 3, 2020 at 4:11 PM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 03:35 PM 10/3/2020, you wrote:
>
> I personally like the idea of a panel light that will make you aware of
> Under and well as Over voltage conditions.
> I have experienced an under voltage on start up. Caused by a defective
> main circuit breaker
> that opened, but did not show an indication that it had mysteriously
> opened.
>
>
> Then I take it that your system was not fitted
> with active notification of low voltage. This
> feature is the FIRST if not the ONLY voltage
> sensing/indicating device NECESSARY for flight
> operations.
>
> Preferably, this light is bright (sunlight viewable)
> and located well within peripheral vision of the pilot.
> Further, it should flash at 2-3 times per second
> (a legacy value for optimal attention getting
> arrived at by numerous human factors studies ).
>
> This light has been a no-extra-charge built in feature
> of virtually all B&C alternator controllers. From
> day-one (about 35 years ago). It was B&C's mission that
> no customer would be without BOTH low volts and
> over volts management.
>
> Luckily, before beginning the taxi, I noted the amp/volt meter was amiss
.
>
> Tested the CB and could not get it to reset.=C3=82 Installed new CB and
had no
> additional problems.
>
>
> Yes, there was an element of luck associated with
> that experience. I'm pleased the event resolved
> without a tense-day-in-the-cockpit.
>
> Along with active notification of low volts, you
> should plan on independent management of an over
> voltage condition with a system that disables
> the alternator within 500 milliseconds of having
> exceeded 16 volts.
>
> Depending on design parameters of the designer,
> the ov event will be over very soon thus leaving
> you with a low volts condition that will be
> annunciated as cited above.
>
> Fit your airplane with those two features and
> all the other voltmeters, ammeters, beeps
> and squawks from the panel mounted goodies
> become mere icing on the cake.
>
>
> Bob . . .
>
Message 2
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| Subject: | Re: voltage monitor |
the rub with low voltage indicators is that they set their low voltage for lead
acid batteries. this is too low and useless for earthx lipo. low voltage warning
must go on below 13.5 volts. when i started this post i talked to b and c
about a warning system they had. the voltage was not adjustable and set for lead
acid......no good for lipo. b and c said that most electronics is adjustable
today and there was never a market for a higher low warning. my system is adjustable
but i do not want to probe my ecu with my computer just to make a limit
change.
earthx users....what's in your wallet? er i mean low voltage setting?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498650#498650
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| Subject: | Re: field current supplied from B lead instead of |
from main bus
At 11:11 PM 10/3/2020, you wrote:
><john_s_bright@yahoo.com>
>
>Hi Bob,
>
>Someone in my sphere suggested getting field current from the B lead
>instead of from the main bus.
>
>This way if the B lead shorts to ground and the fuselink opens, the
>field will be de-energized.
>
>Marked up snip of Z101B attached.
>
>Comments?
If there is a fault that opens the fusible
link, then the alternator is isolated from
the ship's systems. While the field would
still be energized, the resulting condition
is internal to the alternator and not a
threat to the rest of the airplane.
If the regulator senses bus voltage through
the breaker, then you will depress bus voltage
by whatever drop occurs in the b-lead. Further,
the b-terminal to field breaker lead becomes and extension
of the bus and would need to get a fusible
link at the b-lead.
Presently, I see no particular advantage
for doing this.
Bob . . .
Message 4
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| Subject: | Re: voltage monitor |
At 10:58 AM 10/4/2020, you wrote:
>
>the rub with low voltage indicators is that they set their low
>voltage for lead acid batteries. this is too low and useless for
>earthx lipo. low voltage warning must go on below 13.5 volts. when i
>started this post i talked to b and c about a warning system they
>had. the voltage was not adjustable and set for lead acid......no
>good for lipo. b and c said that most electronics is adjustable
>today and there was never a market for a higher low warning. my
>system is adjustable but i do not want to probe my ecu with my
>computer just to make a limit change.
> earthx users....what's in your wallet? er i mean low voltage setting?'
Not sure I understand this. Check out this family of
discharge plots on 3 brands of LiFePo4 batteries
including an EarthX.
https://tinyurl.com/y4nsp8lr
Looks to me like 13.5V is still a good number.
Bob . . .
Message 5
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| Subject: | Re: Can radials of home made ground plane be |
tapered?
At 11:43 AM 9/28/2020, you wrote:
>
>Hi Group FWIW I called Garmin and Stein Air and both said to use a
>ground plane. I also called Vans. On their RV-12 they install the
>GA-35 on a small bracket FWF. I called them and asked about a ground
>plane and they said that the lower cowl acts as a ground plane.
Not one of those assertion suggest that
there is any DATA to support the recommendation.
> Here's a post from a guy in the Vans Forum: "I can tell you
> this...originally
>I installed mine under the cowl with little to no ground plane. It worked....
Not necessarily 'hard' data but certainly
compelling . . .
>Later I installed a bigger ground plane and the signal levels
>definately increased." It was posted in reply from a 12/30/2012
>question in Vans Forum, he doesn't say what model plane he had,
>precisely what antenna or how large of a ground plane. I have now
>heard of several Europa's and a Long EZ using the GA-35 without a
>ground plane with good success. Ron P.
Interesting. I'm not suggesting that a ground
plane under a gps antenna is not beneficial,
only wondering if it's observably useful.
I recall discussions on the amateur built forums
in years past about adding a ram-air induction port
to the airplane's cowl. I seems some builder made
some valid measurements of available manifold pressure
with and without such a feature. He opined there was value
in fabricating one.
I think the discussion died out when
an engine guru reminded us that airspeed
goes up the cube root of h.p. and the fractional
improvement for the addition would be difficult
to measure much less observe in actual practice.
Methinks the GPS ground plane may fall into
this category as well. There are millions
and millions of GPS based appliances that
perform as advertised with exceedingly
'deficient' antennas. It seems that somewhere
between the least and the best, there is
a demonstrable configuration that would save
OBAM aircraft builders hours of no-value-added
effort on their project.
Bob . . .
Message 6
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| Subject: | Re: voltage monitor |
without any mod the 'idiot light' comes preset to warn below 13.0 volts. in a lead
acid set up this would catch the alternator soon after it went off line and
a lead acid would have most of its charge left. when a lipo drops below 13 volts
a lot of its charge is already been used. the goal is to catch the alternator
going out, not to monitor system voltage. my engine needs a battery or a
working alternator to keep running.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498654#498654
Message 7
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| Subject: | Re: voltage monitor |
At 01:10 PM 10/4/2020, you wrote:
>
>without any mod the 'idiot light' comes preset to warn below 13.0
>volts. in a lead acid set up this would catch the alternator soon
>after it went off line and a lead acid would have most of its charge
>left. when a lipo drops below 13 volts a lot of its charge is
>already been used.
Can you confirm that assertion from the
data offered in the three plots I've
posted?
>the goal is to catch the alternator going out, not to monitor system
>voltage. my engine needs a battery or a working alternator to keep running.
The testing I've done suggests that
there MIGHT be a bit of delay in the
LV WARN response . . . but it's minimal.
An LV condition is not a high pucker-factor
event. After the alternator
quits you can finish your cup of coffee
and sandwich, fold the map (if you still use one)
and then proceed to implement plan-b.
Conducting a lightning-fast response to the
light would have no measurable effect on
the outcome of your flight.
This is true of what ever type of battery
chemistry is on board. This is why I've
advised against numerous schemes for automatic
responses to low voltage. Such features only
add complexity that demands pre-flight testing
while failing to reduce risk.
Bob . . .
Message 8
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| Subject: | Re: field current supplied from B lead instead of from |
main bu
nuckolls.bob(at)aeroelect wrote:
> At 11:11 PM 10/3/2020, you wrote:
>
> If there is a fault that opens the fusible
> link, then the alternator is isolated from
> the ship's systems. While the field would
> still be energized, the resulting condition
> is internal to the alternator and not a
> threat to the rest of the airplane.
>
> If the regulator senses bus voltage through
> the breaker, then you will depress bus voltage
> by whatever drop occurs in the b-lead. Further,
> the b-terminal to field breaker lead becomes and extension
> of the bus and would need to get a fusible
> link at the b-lead.
>
> Presently, I see no particular advantage
> for doing this.
>
>
> Bob . . .
Thanks Bob.
--------
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
https://drive.google.com/drive/folders/1u6GeZo6pmBWsKykLNVQMvu4o1VEVyP4K
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498656#498656
Message 9
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| Subject: | Re: voltage monitor |
On 10/4/2020 1:27 PM, Robert L. Nuckolls, III wrote:
> At 01:10 PM 10/4/2020, you wrote:
>>
>> without any mod the 'idiot light' comes preset to warn below 13.0
>> volts. in a lead acid set up this would catch the alternator soon
>> after it went off line and a lead acid would have most of its charge
>> left. when a lipo drops below 13 volts a lot of its charge is already
>> been used.
>
> Can you confirm that assertion from the
> data offered in the three plots I've
> posted?
>
>> the goal is to catch the alternator going out, not to monitor system
>> voltage. my engine needs a battery or a working alternator to keep
>> running.
>
> The testing I've done suggests that
> there MIGHT be a bit of delay in the
> LV WARN response . . . but it's minimal.
>
> An LV condition is not a high pucker-factor
> event. After the alternator
> quits you can finish your cup of coffee
> and sandwich, fold the map (if you still use one)
> and then proceed to implement plan-b.
>
> Conducting a lightning-fast response to the
> light would have no measurable effect on
> the outcome of your flight.
>
> This is true of what ever type of battery
> chemistry is on board. This is why I've
> advised against numerous schemes for automatic
> responses to low voltage. Such features only
> add complexity that demands pre-flight testing
> while failing to reduce risk.
>
> Bob . . .
>
I think I see his point. If the 'stock' alert point is 13V, the EarthX
chart shows that to be at about the 3 AH point of the curve with total
AH capacity of about 11AH when looking at the higher discharge rates
you'd expect from an electronic injection system. Not a big deal if
there's a backup alternator, but being down roughly 1/3 before
notification could be a big deal if you're depending on battery for backup.
Charlie
--
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Message 10
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| Subject: | Re: field current supplied from B lead instead of from |
main bus
Bad idea. How often do "B" leads short to ground?
The "B" lead is not going to short to ground if properly installed.
Adding an extra wire from the alternator to the instrument panel increases the
chances of a failure.
Suppose the alternator stops working for some reason.
It could be a broken belt, bad brushes, broken wire, blown "B" lead fuse.
The pilot will not know the cause. What action will the pilot take?
She might cycle the alternator field switch on and off. If the alternator still
does
not work, she might leave the switch off to conserve the battery.
I see no advantage to adding an extra wire to the engine.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498657#498657
Message 11
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| Subject: | Li-Ion versus LiFePO4 |
At 01:10 PM 10/4/2020, you wrote:
>
>without any mod the 'idiot light' comes preset to warn below 13.0 volts.
>in a lead acid set up this would catch the alternator soon after it went
>off line and a lead acid would have most of its charge left. when a lipo
>drops below 13 volts a lot of its charge is already been used.
Are you perhaps conflating Li-Ion with LiFePo4
chemistries?
Check out this plot https://tinyurl.com/y6o5olae
These curves are examples of the discharge characteristics
of the wildly popular lithium cells offered in the vast
majority of ads on the 'net.
As you can see, the discharge characteristics are
exceedingly different than for LiFePO4.
To achieve 100% charge you must push energy into
these cells at 4.2 volts or so. 3 cells in series
would give us a 'bus voltage' of 12.6v . . . a
tad low. Their end of service voltage of 3 volts
would power our goodies at 9V . . . waaayy too
low.
Okay, 4 cells in series gives us a bus voltage
of 16.8 volts. Yeah . . . I suppose you could
configure a system that would run happily at
that level. MOST modern avionics wouldn't care.
But your battery contactors, light bulbs and
legacy 14v accessories would care. At end of
service we would see 12v . . . just fine but
yes, it would make your existing LV warning
useless.
But are you aware of any BMS supported, engine
cranking batteries offered to the automotive
or aircraft communities that are fitted with
the Li-Ion chemistry?
LiFePo4 is a marriage made in the lab.
A 4-stack array offers full charge and end
of service voltages are quite compatible
with the lead-acid world. That's why all those supplier are
able to offer plug and play lithium upgrades
to virtually everyone . . . including those
who choose to cheat death in those
funny kites with air-thrashers on the
front.
Bob . . .
Message 12
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| Subject: | Re: voltage monitor |
Bob,
I suggest to view Shorai's FAQ page linked below.
https://shoraipower.com/faq
Scroll down and click on the question: Q. Can I use Lead-Acid battery char
gers or charger/tenders?
View the chart on the right side of the page. Note that at 13.0 volts, thes
e LiFe batteries have less than 40% charge left.
Charlie K
On Sunday, October 4, 2020, 02:45:15 PM EDT, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
At 01:10 PM 10/4/2020, you wrote:
--> AeroElectric-List messageposted by: "bobnoffs" <icubob@gmail.com>
without any mod the 'idiot light' comes preset to warn below 13.0 volts.in
a lead acid set up this would catch the alternator soon after it wentoff li
ne and a lead acid would have most of its charge left. when a lipodrops bel
ow 13 volts a lot of its charge is already been used.
=C2- Can you confirm that assertion from the
=C2- data offered in the three plots I've
=C2- posted?
the goal is to catch thealternator going out, not to monitor system voltage
. my engine needs abattery or a working alternator to keep running.
=C2- The testing I've done suggests that
=C2- there MIGHT be a bit of delay in the
=C2- LV WARN response . . . but it's minimal.
=C2- An LV condition is not a high pucker-factor
=C2- event. After the alternator
=C2- quits you can finish your cup of coffee
=C2- and sandwich,=C2- fold the map (if you still use one)
=C2- and then proceed to implement plan-b.
=C2- Conducting a lightning-fast response to the
=C2- light would have no measurable effect on
=C2- the outcome of your flight.
=C2- This is true of what ever type of battery
=C2- chemistry is on board. This is why I've
=C2- advised against numerous schemes for automatic
=C2- responses to low voltage. Such features only
=C2- add complexity that demands pre-flight testing
=C2- while failing to reduce risk.
=C2- Bob . . .
Message 13
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| Subject: | Re: voltage monitor |
>I think I see his point. If the 'stock' alert point is 13V, the
>EarthX chart shows that to be at about the 3 AH point of the curve
>with total AH capacity of about 11AH when looking at the higher
>discharge rates you'd expect from an electronic injection system.
>Not a big deal if there's a backup alternator, but being down
>roughly 1/3 before notification could be a big deal if you're
>depending on battery for backup.
Don't know where the 13.0 point comes from. Both
AEC and B&C have used 13.5 for a couple of decades.
But okay, let's assume 13.0
See tabular data text file. The ETX36 with a 5A
load on it will fall to 13.0 in about 40 seconds.
The image file is from plotred data of the same
test:
Kinda hard to zero in on the finer details of a
couple hour run but it shows that at 67 seconds,
the battery was down to 12.99 with an expenditure
of approx 0.1 AH
Keep in mind that voltage monitoring at
the bus is always tens of millivolts HIGHER
than battery voltage . . . with a similar
departure to the LOWER side during DISCHARGE
conditions.
So assuming one had a LV reporting system that
was not adjustable but accurate to 100 millivolts
or so at 13.0, the resulting delay between
alternator failure and annunciation is still
timely and 'wasted' energy is trivial.
Bob . . .
West Mountain Radio CBA
Test Report: YEAROLDETX36_1
Description: 4 Li-ion cells, 7.5 Ah @ 5.00A
Started At: 01/16/17 16:42:53
Starting Voltage: 13.41 V
Ending Voltage: 11.19 V
Sample Rate: 1.000
Total Time (hh:mm:ss): 2:09:53
Time (hh:mm:ss) Voltage (V) Current Temp (C)
00:00:00 13.409 0.809 0.00
00:00:01 13.409 0.809 0.00
00:00:02 13.231 4.032 0.00
00:00:03 13.184 4.773 0.00
00:00:04 13.184 4.816 0.00
00:00:05 13.165 4.968 0.00
00:00:06 13.140 4.981 0.00
00:00:07 13.135 5.002 0.00
00:00:08 13.135 5.015 0.00
00:00:09 13.135 5.011 0.00
00:00:10 13.135 4.994 0.00
00:00:11 13.130 5.011 0.00
00:00:12 13.100 5.011 0.00
00:00:13 13.100 4.994 0.00
00:00:14 13.090 5.002 0.00
00:00:15 13.085 5.002 0.00
00:00:16 13.085 4.998 0.00
00:00:17 13.085 4.998 0.00
00:00:18 13.080 4.998 0.00
00:00:19 13.085 5.011 0.00
00:00:20 13.060 4.989 0.00
00:00:21 13.065 5.002 0.00
00:00:22 13.050 5.011 0.00
00:00:23 13.045 4.981 0.00
00:00:24 13.036 5.015 0.00
00:00:25 13.035 4.989 0.00
00:00:26 13.035 5.011 0.00
00:00:27 13.035 5.006 0.00
00:00:28 13.035 4.998 0.00
00:00:29 13.035 4.998 0.00
00:00:30 13.035 5.002 0.00
00:00:31 13.031 5.011 0.00
00:00:32 13.020 4.981 0.00
00:00:33 13.016 5.002 0.00
00:00:34 13.021 5.006 0.00
00:00:35 13.006 4.994 0.00
00:00:36 13.006 4.994 0.00
00:00:37 12.991 5.011 0.00
00:00:38 12.986 4.994 0.00
00:00:39 12.986 5.015 0.00
00:00:40 12.986 4.998 0.00
<snip>
Message 14
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| Subject: | Re: voltage monitor |
At 02:18 PM 10/4/2020, you wrote:
>Bob,
>I suggest to view Shorai's FAQ page linked below.
>
>https://shoraipower.com/faq
>
>Scroll down and click on the question: Q. Can I use Lead-Acid
>battery chargers or charger/tenders?
>
>View the chart on the right side of the page. Note that at 13.0
>volts, these LiFe batteries have less than 40% charge left.
That's an open circuit, no-load voltage that speaks
to state of charge. That's not a milestone voltage
for a fully charged battery under load.
Two completely different conditions
Bob . . .
Message 15
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| Subject: | Re: voltage monitor |
hi all,
according to the graph posted bob is right about the very small current drained.
this is not at all how earthx describes their batteries. earthx recommends that
low voltage monitors light up below 13.5 volts.
on the b and c web site they sell an over/under voltage sensor model bc207. the
low voltage light trips at 12.5 volts according to their description.
everything i have learned about the lipo batteries has said they hold their voltage
while discharging. i have always seen a much larger % drop advertised.time
for me to call earthx.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498666#498666
Message 16
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| Subject: | Re: ADS-B and Transponder antenna design... |
I simply carefully spliced the Coax. I tried a 1GHz mux with and without a terminating
resistor and didn't find any better real world performance and it was
harder to package. That's one of the reasons I'd like to find out about the analyzer
performance of these antennas.
Drop me an email as to where to send them. I assume you've got an analyzer? Let
me know where to send it. I'd much rather have them dialed in at 978 as weather
reception range is most important. If I can see 1090 traffic at 5 miles, I'm
happy, but if I can only get 978 towers at 30 or 40 miles... :(
I put my stratux back out of the way as well - talks great to my IFD540 via serial.
I've only got about 3 feet of coax, but around the house, I had these hooked
up to about 10 feet for testing. I'm flying with the Slim-jim, but recently
found a better hiding place to try to di-pole if it'll fit in my spar well without
sacrificing performance. I have 3 turns of coax at the base of the antenna
for a BalUn.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498667#498667
Message 17
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| Subject: | Re: voltage monitor |
On Sun, Oct 4, 2020 at 4:28 PM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> I think I see his point. If the 'stock' alert point is 13V, the EarthX
> chart shows that to be at about the 3 AH point of the curve with total AH
> capacity of about 11AH when looking at the higher discharge rates you'd
> expect from an electronic injection system. Not a big deal if there's a
> backup alternator, but being down roughly 1/3 before notification could be
> a big deal if you're depending on battery for backup.
>
>
> Don't know where the 13.0 point comes from. Both
> AEC and B&C have used 13.5 for a couple of decades.
>
> But okay, let's assume 13.0
>
> See tabular data text file. The ETX36 with a 5A
> load on it will fall to 13.0 in about 40 seconds.
> The image file is from plotred data of the same
> test:
>
> Kinda hard to zero in on the finer details of a
> couple hour run but it shows that at 67 seconds,
> the battery was down to 12.99 with an expenditure
> of approx 0.1 AH
>
> Keep in mind that voltage monitoring at
> the bus is always tens of millivolts HIGHER
> than battery voltage . . . with a similar
> departure to the LOWER side during DISCHARGE
> conditions.
>
> So assuming one had a LV reporting system that
> was not adjustable but accurate to 100 millivolts
> or so at 13.0, the resulting delay between
> alternator failure and annunciation is still
> timely and 'wasted' energy is trivial.
>
>
> Bob . . .
>
I think he's using the EarthX PC680 relacement battery. I used EarthX's
chart for their PC680 replacement, here:
https://earthxbatteries.com/earthx_manual.pdf
and assumed ~12-14 A load, which is typical for full electronic engine
control with electronic injection. According to EarthX the 680 replacement
hovers around 13 V until around 3 AH has been depleted.
You'd know a lot better than me where the LoVolts setpoint is with B&C
stuff; that's why I said 'if'. :-)
Charlie
Message 18
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| Subject: | Re: ADS-B and Transponder antenna design... |
Sounds affordable to me. I don't have an analyzer now, but I've been
planning to purchase one. This will motivate me. :-)
I'll send my address direct to your email address.
Thanks!
Charlie
On Sun, Oct 4, 2020 at 5:12 PM andymeyer <meyerkc135@gmail.com> wrote:
> >
>
> I simply carefully spliced the Coax. I tried a 1GHz mux with and without a
> terminating resistor and didn't find any better real world performance and
> it was harder to package. That's one of the reasons I'd like to find out
> about the analyzer performance of these antennas.
>
> Drop me an email as to where to send them. I assume you've got an
> analyzer? Let me know where to send it. I'd much rather have them dialed in
> at 978 as weather reception range is most important. If I can see 1090
> traffic at 5 miles, I'm happy, but if I can only get 978 towers at 30 or 40
> miles... :(
>
> I put my stratux back out of the way as well - talks great to my IFD540
> via serial. I've only got about 3 feet of coax, but around the house, I had
> these hooked up to about 10 feet for testing. I'm flying with the Slim-jim,
> but recently found a better hiding place to try to di-pole if it'll fit in
> my spar well without sacrificing performance. I have 3 turns of coax at the
> base of the antenna for a BalUn.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=498667#498667
>
>
Message 19
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| Subject: | Re: voltage monitor |
At 04:50 PM 10/4/2020, you wrote:
>
>hi all,
> according to the graph posted bob is right about the very small
> current drained.
>this is not at all how earthx describes their batteries.
Can you point us to the download for
information that gives you concern?
>earthx recommends that low voltage monitors light up below 13.5 volts.
B&C and I both have promoted that lv setpoint
value for decades . . .
> on the b and c web site they sell an over/under voltage sensor
> model bc207. the low voltage light trips at 12.5 volts according to
> their description.
>
That device was originally crafted
for ultralights about 30 years ago.
In fact, it was the first, stand-alone
monitor device produced there.
It was never intended for installation
in 'real' airplanes. I really wish
they didn't sell that any more but
I think Aircraft Spruce shows it in
their catalog. NOT RECOMMENDED FOR
NEW DESIGN.
> everything i have learned about the lipo batteries has said they
> hold their voltage while discharging.
And in what way does the data I've posted
argue with that?
The AeroVoltz plot shows a working range
on the order of 13.2 to 12.5 volts.
Miady 13.2 to about 12.0
EarthX from 13.2 to 12.5
Where are you going to find anything
flatter for a discharge curve? All three
deliver power within a 5% or smaller
window.
I have always seen a much larger % drop advertised.time for me to call earthx.
. . . and ask what? Help me understand
your question. Before you seek verbal
guidance, let us examine data-in-print
and data-measured so that disconnects can
be clearly articulated. I'd be happy
to call them myself if there are real
points of contention.
I've talked to both EarthX and Shorai
numerous times but a considerable time
ago . . . wouldn't mind renewing some
contacts.
Bob . . .
Message 20
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| Subject: | Re: voltage monitor |
From: Technical Manual for Model No. LR3D-14 and LR3D-28 Linear
RegulatorWith Over-Voltage Protection, Low-Voltage Sensing, And
Field-Adjustable Charging Voltage
"The LV warning light will begin to flash when the voltage sensed at
terminal 3 drops to approximately 12.7V and below"
Disregard if this is not relevant to this discussion.
On Sun, Oct 4, 2020 at 2:26 PM Charlie England <ceengland7@gmail.com> wrote:
>
>
> On Sun, Oct 4, 2020 at 4:28 PM Robert L. Nuckolls, III <
> nuckolls.bob@aeroelectric.com> wrote:
>
>> I think I see his point. If the 'stock' alert point is 13V, the EarthX
>> chart shows that to be at about the 3 AH point of the curve with total AH
>> capacity of about 11AH when looking at the higher discharge rates you'd
>> expect from an electronic injection system. Not a big deal if there's a
>> backup alternator, but being down roughly 1/3 before notification could be
>> a big deal if you're depending on battery for backup.
>>
>>
>> Don't know where the 13.0 point comes from. Both
>> AEC and B&C have used 13.5 for a couple of decades.
>>
>> But okay, let's assume 13.0
>>
>> See tabular data text file. The ETX36 with a 5A
>> load on it will fall to 13.0 in about 40 seconds.
>> The image file is from plotred data of the same
>> test:
>>
>> Kinda hard to zero in on the finer details of a
>> couple hour run but it shows that at 67 seconds,
>> the battery was down to 12.99 with an expenditure
>> of approx 0.1 AH
>>
>> Keep in mind that voltage monitoring at
>> the bus is always tens of millivolts HIGHER
>> than battery voltage . . . with a similar
>> departure to the LOWER side during DISCHARGE
>> conditions.
>>
>> So assuming one had a LV reporting system that
>> was not adjustable but accurate to 100 millivolts
>> or so at 13.0, the resulting delay between
>> alternator failure and annunciation is still
>> timely and 'wasted' energy is trivial.
>>
>>
>>
>>
>>
>> Bob . . .
>>
> I think he's using the EarthX PC680 relacement battery. I used EarthX's
> chart for their PC680 replacement, here:
> https://earthxbatteries.com/earthx_manual.pdf
> and assumed ~12-14 A load, which is typical for full electronic engine
> control with electronic injection. According to EarthX the 680 replacement
> hovers around 13 V until around 3 AH has been depleted.
>
> You'd know a lot better than me where the LoVolts setpoint is with B&C
> stuff; that's why I said 'if'. :-)
>
> Charlie
>
>
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