Today's Message Index:
----------------------
1. 09:29 AM - Re: Z-19 + Ford regulator killing batteries? (Vern Little)
2. 09:47 AM - Re: Parallel operations of generators/alternators (Robert L. Nuckolls, III)
3. 10:37 AM - Re: Parallel operations of generators/alternators (Corrected Link) (Robert L. Nuckolls, III)
4. 10:53 AM - Re: Z-19 + Ford regulator killing batteries? (John Morgensen)
5. 12:01 PM - Re: Z-19 + Ford regulator killing batteries? (Robert L. Nuckolls, III)
6. 12:03 PM - Re: Hall effect sensors under the cowl? (Robert L. Nuckolls, III)
7. 12:20 PM - isolation circuit (jamesneely)
8. 04:22 PM - Re: glideslope antenna was lower OM minima (Chris)
9. 09:42 PM - Re: Re: Balum Construction (The Kuffels)
Message 1
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Subject: | Re: Z-19 + Ford regulator killing batteries? |
In my opinion your regulator is working fine, but the wiring to the
inputs of your regulator is suspect. Poor connections, too small a
gauge of wiring or faulty (resistive) switches will cause overvoltage
when the alternator is heavily loaded.
Bob has an article that discusses this, you'll have to search his
website.
Here's the fix that I did on my RV-9A to eliminate this problem:
http://www.vx-aviation.com/rv-9a/photos/Electrical/Regulator_relay_app.jp
g
The K3 relay is wired firewall-forward directly from the battery (using
a fuselink) and the regulator. D17 is not strictly necessary, but
guards against a dual failure (stuck relay and overvoltage at the same
time). I went from varying charging voltage (up to 15.5V) to rock-solid
14.2V.
Vern Little
Vx Aviation
----- Original Message -----
From: Mark R. Supinski
To: aeroelectric-list@matronics.com
Sent: Monday, March 23, 2009 8:08 PM
Subject: Re: AeroElectric-List: Z-19 + Ford regulator killing
batteries?
On Mon, Mar 23, 2009 at 5:52 PM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
At 04:52 PM 3/22/2009, you wrote:
Hello All-
I have a system based on the Z-19 drawing for an EFI based
airplane. Getting ready to fly for the first time, but I am now almost
convinced my setup is killing the batteries for some reason. I have
gone through 3 already over the last 16 months just testing out the
airplane & running the engine in test spurts.
Here's the symptoms, hopefully someone can shed some light:
a.. Recommended Ford regulator
b.. 2x UB 12220 22AH batteries (3" w x 7" l x 6.5" h)
c.. 80 Amp alternator
My engine monitor keeps complaining that the alternator is putting
out too high a voltage (typically 15.0 - 15.5 after start with the
engine running). Don't know if this is just because the batteries were
just discharged starting the engine -- haven't had long enough engine
runs to see if the load drops.
No . . . the regulator has one responsibility only. HOLD the
bus at 14.2 to 14.6 volts under ALL conditions where the
alternator is turning fast enough to shoulder system load
AND recharge the battery.
--------------------------------------------------------
So this suggests that the regulator has a problem. It is certainly
generating bus voltages in excess of 15.0v -- I have 2 devices which
display voltage & both agree within 1v of each other that voltages are
above 15. I can't imagine the regulator is adjustable, so it must be a
dud, correct?
--------------------------------------------------------
All the batteries fail the same way -- suddenly they won't hold a
charge & output only 3v or so. Just had another one fail today.
After doing some additional reading, I am starting to wonder
whether these seal mat batteries are such a good idea. The literature
suggests they are quite finicky on how to recharge.
EVERY battery hates to be charged at 15+ volts. The
difference is that you can pour water into some
batteries . . . others simply become re-cycle
fodder.
I must confess that I may have killed the batteries myself. I
have an external battery cart & I have simply been hooking the batteries
up & setting the charger to 40amp when the batteries were running down.
The batteries seem to want an initial charge of 3 amps or less before
upping the amperage.
An external power supply should ALSO be set
for 14.2 volts. You say it's a "battery cart"
with a current setting? Sounds like an AC mains
power supply of some kind. 14.2 volts is the
rule. Recharge rates are a problem only if
you deeply discharge the batteries. If you have
ground power available, then there's no good
reason to deeply discharge the battries.
--------------------------------------------------------
The 110v charger allows one to set how many amps to charge with & for
how long -- it puts out 14.5V while charging. However -- *EVERY* AGM
battery I have seen claims a maximum charging amps of 7A or less. This
confuses me since I don't know how to control this when they are being
recharged via the alternator. Some I have seen say "Initial" charging
amps, others say Max.
Here is what I see in the manufacturer's literature for my batteries:
Charge Method (Constant Voltage) - Cycle Use - Initial Current - 7.7A
or smaller
Charge Method (Constant Voltage) - Cycle Use - Control voltage - 14.5
- 14.9 V
Charge Method (Constant Voltage) - Float Use - Control Voltage - 13.6
- 13.8 V
There is no good reason to discharge the batteries... except when one
forgets to turn off the master switch & the ECU quietly continues
running all week as the acft sits in the hangar.
--------------------------------------------------------
It sounds like lack of attention to voltage control
is the root cause of your difficulties.
--------------------------------------------------------
If certainly has my attention now! If step one is to replace that
regulator, I'll do it forthwith. If another step is to follow a
different procedure when ground charging (or get a smaller charger) I'll
certainly do that too.
Thanks, Bob -- appreciate the help.
Mark
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
ist"
target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
Message 2
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Subject: | Re: Parallel operations of generators/alternators |
At 08:36 AM 3/22/2009, you wrote:
>Good Morning Chase,
>
>Different Bob here, but it is my understanding that a properly
>operating alternator has diodes or other rectification devices in
>the circuit that allow us to have direct current, not alternating
>current, at our disposal.
>
>If we hook two alternators together at the point where they are
>still producing alternating current, the current will need to be put
>in phase or "paralleled" as the big boys say.
>
>Once the output has been rectified or smoothed out enough to be
>considered direct current, paralleling ceases to be a problem. The
>source that has the highest voltage will hog the load. The lower
>voltage source will just wait until the voltage gets down to its
>level before it adds anything to the mix. That is how we balance the
>load between two power output devices, we mess with the voltage and
>the resistance between the current producing entities.
>
>Make any sense at all?
Absolutely! With AC machines (like those that power
the national grid), the task of paralleling multiple
alternators is two-fold. (1) they need to be adjusted
for output voltage so as to limit their output below
rated value and not upset system voltage such that
other alternators shut down and (2) their phase angle
of alternating current must be in lock step with the
system. In DC machines there is no phase angle of
output power to consider, only output voltage
levels with respect to system requirements and
PARALLELING multiple machines such that they SHARE
appropriate proportions of total load.
Back in the good ol' days of carbon pile regulators
on DC generators, this was a relatively easy task.
Each generator already had a really handy feature for
measuring the generator's output current. Large
generators were fitted with "compensation" or
"interpole" windings that kept the axis of field
flux from "twisting" due to reaction flux in the
armature. Without these compensation windings.
Armature reaction flux moved the ideal commutation
point out from under the brushes as output load
increased. This caused an increase in arcing at the
brushes with commensurate increases in wear. See:
http://en.wikipedia.org/wiki/Commutator_(electric)
This compensation winding had a rather large
voltage drop when the generator was producing
full load . . . something on the order of 5%
of system voltage. This offered a great opportunity
to make two regulators negotiate with each other
for the purpose of sharing loads between two
generators. See:
http://aeroelectric.com/Pictures/Schematics/Parallel_Aircraft_Generators.jpg
Alternators came along and our handy-dandy
paralleling signal went away.
The first two-alternator system integration
task I was aware of happened on the Cessna 337
while I was a tech-writer there. We struggled
with the task of getting two alternators to
balance their outputs. It seems that the smallest
change in voltage setpoint of one alternator would
cause the higher setting machine to pick up most
if not all of the total load. Regulators then
(and even today) are generally incapable of
precise balancing of two machines based solely
on the sensing of voltage. The "fix" was to
run BOTH alternators from the same regulator.
The pilot could switch between a main regulators
and a spare. Beech did the same thing on the
Baron.
I've designed two alternator-specific balancing
systems. One was offered to Cessna many moons
ago to balance alternators in the T303 Crusader.
In this approach we regulated voltage at the
alternator's b-lead and case ground. We depended
on the resistance of ship's wiring between b-lead
and the bus to "ballast" tiny variations in setpoint.
Another approach done later was an add-on box
that would take control of one regulator as
a "slave" forced to track variations in the
"master". Both approaches worked well but they've
never taken deep roots because alternators are
generally limited to piston engine aircraft.
Every manufacturer would be really pleased to get
out of the piston business if the market would
let them . . . so let's not spend a lot of $time$
upgrading alternator systems to the best-we-know-how-
to-do.
Years later we're presented with an opportunity
to install two alternators of significant capability
on one engine. Okay, what's a mother to do? One
of the most practical approaches is illustrated in
Z-12. One main alternator with a smaller stand-b7
machine held in reserve. The other was Z-14 where
both alternators are assigned normal operations
tasks commensurate with their size in totally
independent systems. Then provide cross-feed
capability for cranking and mitigation of
alternator failure events. This eliminates
the need for anything special in the way of
alternator paralleling regulators.
Bottom line is that figuring out a way to avoid
paralleling alternators is a good thing to do.
None of the Z-figures features feature paralleled
alternator operations.
Bob . . .
Message 3
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Subject: | Re: Parallel operations of generators/alternators (Corrected |
Link)
At 11:44 AM 3/24/2009, you wrote:
>At 08:36 AM 3/22/2009, you wrote:
>>Good Morning Chase,
>>
>>Different Bob here, but it is my understanding that a properly
>>operating alternator has diodes or other rectification devices in
>>the circuit that allow us to have direct current, not alternating
>>current, at our disposal.
>>
>>If we hook two alternators together at the point where they are
>>still producing alternating current, the current will need to be
>>put in phase or "paralleled" as the big boys say.
>>
>>Once the output has been rectified or smoothed out enough to be
>>considered direct current, paralleling ceases to be a problem. The
>>source that has the highest voltage will hog the load. The lower
>>voltage source will just wait until the voltage gets down to its
>>level before it adds anything to the mix. That is how we balance
>>the load between two power output devices, we mess with the voltage
>>and the resistance between the current producing entities.
>>
>>Make any sense at all?
>
> Absolutely! With AC machines (like those that power
> the national grid), the task of paralleling multiple
> alternators is two-fold. (1) they need to be adjusted
> for output voltage so as to limit their output below
> rated value and not upset system voltage such that
> other alternators shut down and (2) their phase angle
> of alternating current must be in lock step with the
> system. In DC machines there is no phase angle of
> output power to consider, only output voltage
> levels with respect to system requirements and
> PARALLELING multiple machines such that they SHARE
> appropriate proportions of total load.
>
> Back in the good ol' days of carbon pile regulators
> on DC generators, this was a relatively easy task.
> Each generator already had a really handy feature for
> measuring the generator's output current. Large
> generators were fitted with "compensation" or
> "interpole" windings that kept the axis of field
> flux from "twisting" due to reaction flux in the
> armature. Without these compensation windings.
> Armature reaction flux moved the ideal commutation
> point out from under the brushes as output load
> increased. This caused an increase in arcing at the
> brushes with commensurate increases in wear. See:
>
>http://tinyurl.com/bkhzb5
>
> This compensation winding had a rather large
> voltage drop when the generator was producing
> full load . . . something on the order of 5%
> of system voltage. This offered a great opportunity
> to make two regulators negotiate with each other
> for the purpose of sharing loads between two
> generators. See:
>
>http://aeroelectric.com/Pictures/Schematics/Parallel_Aircraft_Generators.jpg
>
> Alternators came along and our handy-dandy
> paralleling signal went away.
>
> The first two-alternator system integration
> task I was aware of happened on the Cessna 337
> while I was a tech-writer there. We struggled
> with the task of getting two alternators to
> balance their outputs. It seems that the smallest
> change in voltage setpoint of one alternator would
> cause the higher setting machine to pick up most
> if not all of the total load. Regulators then
> (and even today) are generally incapable of
> precise balancing of two machines based solely
> on the sensing of voltage. The "fix" was to
> run BOTH alternators from the same regulator.
> The pilot could switch between a main regulators
> and a spare. Beech did the same thing on the
> Baron.
>
> I've designed two alternator-specific balancing
> systems. One was offered to Cessna many moons
> ago to balance alternators in the T303 Crusader.
> In this approach we regulated voltage at the
> alternator's b-lead and case ground. We depended
> on the resistance of ship's wiring between b-lead
> and the bus to "ballast" tiny variations in setpoint.
>
> Another approach done later was an add-on box
> that would take control of one regulator as
> a "slave" forced to track variations in the
> "master". Both approaches worked well but they've
> never taken deep roots because alternators are
> generally limited to piston engine aircraft.
> Every manufacturer would be really pleased to get
> out of the piston business if the market would
> let them . . . so let's not spend a lot of $time$
> upgrading alternator systems to the best-we-know-how-
> to-do.
>
> Years later we're presented with an opportunity
> to install two alternators of significant capability
> on one engine. Okay, what's a mother to do? One
> of the most practical approaches is illustrated in
> Z-12. One main alternator with a smaller stand-b7
> machine held in reserve. The other was Z-14 where
> both alternators are assigned normal operations
> tasks commensurate with their size in totally
> independent systems. Then provide cross-feed
> capability for cranking and mitigation of
> alternator failure events. This eliminates
> the need for anything special in the way of
> alternator paralleling regulators.
>
> Bottom line is that figuring out a way to avoid
> paralleling alternators is a good thing to do.
> None of the Z-figures features feature paralleled
> alternator operations.
>
> Bob . . .
Message 4
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Subject: | Re: Z-19 + Ford regulator killing batteries? |
Vern Little wrote:
>
> http://www.vx-aviation.com/rv-9a/photos/Electrical/Regulator_relay_app.jpg
>
Slightly off topic, but I notice a Hall Effect sensor (S5) that appears
to be on the forward side of the firewall. I am installing an AFS 3500
with a Hall Effect sensor and two alternators ala Z-13/8. I would like
to keep all of the alternator and regulator stuff firewall forward but
the EMS wants the Hall sensor on the cabin side. Is there any problem
with the Hall sensor living on the firewall?
John Morgensen
RV9A
Message 5
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Subject: | Re: Z-19 + Ford regulator killing batteries? |
> No . . . the regulator has one responsibility only. HOLD the
> bus at 14.2 to 14.6 volts under ALL conditions where the
> alternator is turning fast enough to shoulder system load
> AND recharge the battery.
>
>
>--------------------------------------------------------
>
>So this suggests that the regulator has a problem. It is certainly
>generating bus voltages in excess of 15.0v -- I have 2 devices which
>display voltage & both agree within 1v of each other that voltages
>are above 15. I can't imagine the regulator is adjustable, so it
>must be a dud, correct?
>
>--------------------------------------------------------
Vern brings up another possibility . . . excessive
drop in the regulator's field supply wiring. Take
a look at:
http://aeroelectric.com/Pictures/Regulators/Ford_Test_Reg.jpg
Wire up your regulator like this and install it
directly to the back of the alternator. See what
happens to the bus voltage when all aircraft wiring
is out of the circuit.
I am skeptical that this is the problem. THAT large
an upward shift would almost always cause severe
instability too . . . but give it a try and report
back.
---------------
> An external power supply should ALSO be set
> for 14.2 volts. You say it's a "battery cart"
> with a current setting? Sounds like an AC mains
> power supply of some kind. 14.2 volts is the
> rule. Recharge rates are a problem only if
> you deeply discharge the batteries. If you have
> ground power available, then there's no good
> reason to deeply discharge the battries.
>
>
>--------------------------------------------------------
>
>The 110v charger allows one to set how many amps to charge with &
>for how long -- it puts out 14.5V while charging. However --
>*EVERY* AGM battery I have seen claims a maximum charging amps of 7A
>or less. This confuses me since I don't know how to control this
>when they are being recharged via the alternator. Some I have seen
>say "Initial" charging amps, others say Max.
>
>Here is what I see in the manufacturer's literature for my batteries:
>
>Charge Method (Constant Voltage) - Cycle Use - Initial Current -
>7.7A or smaller
>Charge Method (Constant Voltage) - Cycle Use - Control voltage - 14.5 - 14.9 V
>Charge Method (Constant Voltage) - Float Use - Control Voltage - 13.6 - 13.8 V
>
>There is no good reason to discharge the batteries... except when
>one forgets to turn off the master switch & the ECU quietly
>continues running all week as the acft sits in the hangar.
Okay. Assuming the manufacturer's literature is the
"bible" for battery recharge protocols. How are you
going to comply with them after the airplane is
finished?
If you've every driven a car with a battery ammeter
(discharge-zero-plus display) you'll recall that after
starting the engine, the ammeter lays over to the charge
side with some gusto. After a few minutes, it tapers back
to some point just above zero. The same thing will happen
in your airplane. After cranking the engine (and perhaps
running some electro-whizzies during pre-flight) how do
you plan to limit the recharge rates to values requested
by the manufacturer of your battery?
The point is there is no practical way to limit the
recharge rate . . . nor is it necessary.
>If certainly has my attention now! If step one is to replace that
>regulator, I'll do it forthwith. If another step is to follow a
>different procedure when ground charging (or get a smaller charger)
>I'll certainly do that too.
The charger you have is just fine. It sounds like
some form of programmable 'smart charger'. When
used to recharge a stand alone battery, it will
have a recharge profile something like this:
http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf
Here's what another charger does when it was
being used like a "ground power" support supply.
http://www.aeroelectric.com/Pictures/Curves/schumacher_4.jpg
Another concern is the 22 a.h. rating of the batteries.
This battery package size started out as a 17 a.h.
device. In later years 20 and now 22 a.h.
ratings were offered. I'm thinking they may have
achieved a larger 20 hour discharge capability at
the expense of robustness.
If you replace these critters, I'd have more
confidence in their robustness as beat-n-bash
airplane batteries if they were rated more like
their ancestors. A validation of this idea can
be found in ratings for the Odyssey PC680 which
is rated at 17 a.h. The vast majority of
product in that package size are 17 or 18 a.h.
batteries. I think I'd steer clear of "stretched"
versions.
Bob . . .
Message 6
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Subject: | Re: Hall effect sensors under the cowl? |
>Slightly off topic, but I notice a Hall Effect sensor (S5) that
>appears to be on the forward side of the firewall. I am installing
>an AFS 3500 with a Hall Effect sensor and two alternators ala
>Z-13/8. I would like to keep all of the alternator and regulator
>stuff firewall forward but the EMS wants the Hall sensor on the
>cabin side. Is there any problem with the Hall sensor living on the firewall?
The hall-sensor is an electronic device with
some temperature effects for both calibration
and upper limits for operating temperatures.
The automotive industry has been running
these critters under the hood for years.
I can't speak to the science for EMS
recommendations. I suspect the real risks
to satisfactory performance are insignificant.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 7
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Subject: | isolation circuit |
I have a flightline fl-760 and the manual says that both mikes go hot on transmit.
That doesn't seem a like a great idea, particularly in a noisy cockpit.
They mention an optional isolation relay board, but apparently they never did
produce it, so I have to make up my own.
The problem is that while I can solder just fine, I suck at designing circuits.
Has anyone made one of these boards, or has a schematic that I can work from?
or any source for buying such beast?
thanx,
James
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=236003#236003
Message 8
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Subject: | Re: glideslope antenna was lower OM minima |
Might look at a Comant CE193, It can mount on the windscreen center post (if
you have one). I am going to try it on my RV-10. It was a salvage item for
$38.
-Chris Lucas
RV-10, #40072
----- Original Message -----
From: "Chris Stone" <rv8iator@earthlink.net>
Sent: Sunday, March 22, 2009 2:24 PM
Subject: AeroElectric-List: glideslope antenna was lower OM minima
> <rv8iator@earthlink.net>
>
>
>>
>>
> Now that we have settled the marker beacon issue...
>>
> What are the options for locating a glideslope antenna on an RV-8?
>>
> I am building my panel and suddenly had an OH ---- moment. I completely
> forgot the GS antenna. My vert stab/rudder are complete so I am curious as
> to if anyone has figured out another location for placing the dipole
> whisker antenna for the GS receiver? I looked at the dipole strip antenna
> but it requires a flat composite surface 40" deep perpendicular to the
> longitudinal axis of the aircraft. So that seem to rule out the wingtip.
> I had a suggestion from my local avionics shop to mount a dipole whisker
> ant. under the horz. stab. This appears to be difficult at best. What
> would be the effect on the antenna reception being two inches below a
> large ground plane?
> I am really trying to avoid tearing of the fiberglass tip on the vert.
> stab. to mount a dipole whisker. It's also unsightly!
>>
> plan the build... build the plan. Except when the old brain misfires.
>>
> Chris Stone
> RV-8 (eventually)
> Newberg OR.
>>
>>
>>Well, Old Bob, I guess the story is to keep the Marker Beacon receiver off
>>the panel. I asked one question and got a different answer. However, your
>>input is much appreciated. I guess I won't miss the receiver and it will
>>simplify my panel. (However, you are right that it was pleasant hearing
>>the signal when you overflew the airports.) Good Bye KR22.
>>--Jose
>>
>>
>>
>>
>>Read this topic online here:
>>
>>http://forums.matronics.com/viewtopic.php?p=235407#235407
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
Message 9
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Subject: | Re: Balum Construction |
To expand what Bob said:
<< http://www.aeroelectric.com/articles/BALUN/Balun_Fabrication.html
The BALUN shown on my website is cut for 1/4-wave in free space >>
The velocity factor for RG-400 is 0.70 (for RG-58 it's 0.66). This means a
signal travels at 70% the speed of light in free space. Thus Bob's 1/4 wave
length of 26" is correct for the horizontal antenna lines (velocity factor
of about 0.98) but the coax balun length should be reduced by a factor of
0.70, that is a length of 18 1/4".
Tom Kuffel
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