Today's Message Index:
----------------------
1. 02:56 AM - Re: Microprocessor based Fuel Gauge Linearizer (Wolfgang Trinks)
2. 03:27 AM - Re: Microprocessor based Fuel Gauge Linearizer (Boyd C. Braem)
3. 06:03 AM - Re: Microprocessor based Fuel Gauge Linearizer (Alex Peterson)
4. 07:19 AM - Re: Microprocessor based Fuel Gauge Linearizer (Finn Lassen)
5. 07:43 AM - Small aux battery with Z-13 (Fred Stucklen)
6. 09:19 AM - Re: (non?) Microprocessor based Fuel Gauge Linearizer (Eric M. Jones)
7. 09:57 AM - Re: Small aux battery with Z-13 (czechsix@juno.com)
8. 10:22 AM - Re: Re: (non?) Microprocessor based Fuel Gauge (RSwanson)
9. 10:26 AM - (Gary Casey)
10. 10:57 AM - Re: Re: (non?) Microprocessor based Fuel Gauge Linearizer (Cy Galley)
11. 11:13 AM - Re: Re: (non?) Microprocessor based Fuel Gauge Linearizer (Tom Schiff)
12. 11:16 AM - Re: Re: (non?) Microprocessor based Fuel Gauge (Charlie & Tupper England)
13. 11:21 AM - Re: Microprocessor based Fuel Gauge Linearizer (Tom Schiff)
14. 11:25 AM - Re: Microprocessor based Fuel Gauge Linearizer (Tom Schiff)
15. 04:34 PM - Headphone noise on transmit (Duncan McBride)
16. 04:39 PM - Re: Source for Pins & Extraction tools (Paul McAllister)
17. 06:09 PM - Re: Source for Pins & Extraction tools (Bill Steer)
18. 10:23 PM - Unnecessary fuel gauges!!!? (Rob W M Shipley)
19. 10:23 PM - : The value talking about simple-ideas . . . (Rob W M Shipley)
Message 1
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| Subject: | Re: Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Wolfgang Trinks" <Wolfgang.Trinks@flugbereitschaft.com>
I agree that a fuel totalizer in combination with a fuel gauge with a
certain tolerance but precisly showing low fuel situation is a reasonable
way to go.
But there are also others:
I did linearize a the fuel gauge once on my daycruiser(boat). What appeared
to be a weekend programming job on a 80C515 turned into a small >Joint
Strike Fighter< project.
First of all, giving the situation of flat tanks with irregular shapes you
have to determine the funtion of fuel volume versus measuring height of your
sensor at a given sensor position mathematicly using linear algebra. This is
a must.
As this can turn into a nightmare espacially if the tank is inclined during
climb or decent there is a way making things easier(You can neglect bank
because a plane is flown coordinated 99% of the fight time).
Devide your tank in your mind into boxes and put a sensor in the middle of
each box. The smaller the boxes the lower is the influence of the incline
and the more precisly you can determine the volume versus measuring height
by simple trigometrie. The sum of all sensor added one by one will be the
full tank reading where the max value of every sensor equals the
contribution of his box to the total volume. The more boxes, the more
precise and more expensive. So there must be a compromise, but this is
strongly dependent on the shape of the tank.
Anyway when I did this I programmed my f(fuel) in a pascal programm where I
simulated the different incline and was able to play arround with the number
and position of the virtual boxes. It turned out that I could come below 1%
error with 3 sensors on a tank measuring 80cm x 50cm x 180cm in angles up to
15 degree in most unfavourable axis. This was a quite positive experiance. I
think also for a plane with a LL100 grade burning engine 15 degree of
continious pitch up during climb should be far enough.
If you do this you have got the problem on the root and depending on the
type of sensor there will be hardly any linearizing nessecary.
On my boat I used VDO linear resistence floaters and the results where
perfect.
If I would have to do it on a plane today I would use a capacitive system as
sensors because you could very easily build your own sensors (basic
machining required) and finetune the sensors to the tank shape.It also shows
the weight of fuel in the tanks which is the correct measure for your
endurance(ok, this is academic with those tiny volumes).
To get a feeling for all this just look what the big ones are doing if they
need fuel indicators that are serious(Cessna 340,414, King Air, Citation,
all big jets)
Wolfgang...
----- Original Message -----
From: "Tom Schiff" <tomschiff@attbi.com>
Subject: RE: AeroElectric-List: Microprocessor based Fuel Gauge Linearizer
> --> AeroElectric-List message posted by: "Tom Schiff"
<tomschiff@attbi.com>
>
> The problem is that the FAA requires that there be a fuel gage but only
> requires that is shows when the tank is empty. I have been using a fuel
> flow in my C-150 for several months. I have been updating the amount
> remaining every time I fill by the exact amount that I have filled. It
> has been agreeing with the amount determined by sticking the tanks.
> After many fills and over 100 gallons of fuel burned it is still within
> .2 gallons. So you could probably get away with a fuel gage that is in
> reality a fuel flow gage but if you got caught you would be in trouble.
>
> My ideal fuel gage would be several sensors of the type where a led
> shines a light through a prism. When the prism is submerged in gas the
> light shines on a photo sensor and indicates that the sensor is below
> the level of the fuel. The sensors would be at various levels in each
> tank an they would light two sets of led indicators on in the cockpit
> and another aggacent to the filler port. I this way I would know when I
> was about to overfill the tanks. I saw a Money that had a fuel gage next
> to the filler port and that is where I got the idea from. Because you
> have absolutle freedom where you place the sensors you wouldn't have to
> worry about the non linearitys of flat tanks that are inclined at an
> angle
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric
> M. Jones
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Microprocessor based Fuel Gauge Linearizer
>
> --> AeroElectric-List message posted by: "Eric M. Jones"
> <emjones@charter.net>
>
> Neil Hulin's comment about using a fuel totalizer instead of a fuel
> gauge linearizer has been burning a hole in my brain. I believe he is
> right....
>
> Here's the deal--
>
> You only need one fuel totalizer meter if you take fuel from only one
> tank at a time. The fuel quantity meter (and memory) for that tank is
> simply updated as required. I trust in this system, totalizers really
> work well.
> Consider too, that you wouldn't need fuel-level senders or gauges at
> all. Always problematic devices. You also would not need anti-slosh
> electronic filters either. My airplane just got a whole lot lighter!
>
> There are a few practical concerns--how do we know the tank is at the
> level the "gauge" says it is? Well, I always checked it visually with a
> wooden stick anyway. So when tanks are refilled they must be filled to
> the top (ideally) and visually checked. You really wanted the fuel flow
> rate anyway. Not a bad tradeoff.
>
> Eric M. Jones
>
> The whole difference between construction and creation is exactly this:
> that a thing constructed can only be loved after it is constructed;
> but a thing created is loved before it exists.
> - Charles Dickens
>
>
Message 2
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| Subject: | Re: Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Boyd C. Braem" <bcbraem@comcast.net>
The fuel flow totalizer (or whatever--Flowscan?, I believe) that talks
to my VM-1000 is consistently within 0.1 gal and has been since 1998. I
could just tape over my analog guages for all the good that they do, I
mean, my watch is better.....
Tom Schiff wrote:
>--> AeroElectric-List message posted by: "Tom Schiff" <tomschiff@attbi.com>
>
>The problem is that the FAA requires that there be a fuel gage but only
>requires that is shows when the tank is empty. I have been using a fuel
>flow in my C-150 for several months. I have been updating the amount
>remaining every time I fill by the exact amount that I have filled. It
>has been agreeing with the amount determined by sticking the tanks.
>After many fills and over 100 gallons of fuel burned it is still within
>.2 gallons. So you could probably get away with a fuel gage that is in
>reality a fuel flow gage but if you got caught you would be in trouble.
>
>My ideal fuel gage would be several sensors of the type where a led
>shines a light through a prism. When the prism is submerged in gas the
>light shines on a photo sensor and indicates that the sensor is below
>the level of the fuel. The sensors would be at various levels in each
>tank an they would light two sets of led indicators on in the cockpit
>and another aggacent to the filler port. I this way I would know when I
>was about to overfill the tanks. I saw a Money that had a fuel gage next
>to the filler port and that is where I got the idea from. Because you
>have absolutle freedom where you place the sensors you wouldn't have to
>worry about the non linearitys of flat tanks that are inclined at an
>angle
>
>-----Original Message-----
>From: owner-aeroelectric-list-server@matronics.com
>[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric
>M. Jones
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Microprocessor based Fuel Gauge Linearizer
>
>--> AeroElectric-List message posted by: "Eric M. Jones"
><emjones@charter.net>
>
>Neil Hulin's comment about using a fuel totalizer instead of a fuel
>gauge linearizer has been burning a hole in my brain. I believe he is
>right....
>
>Here's the deal--
>
>You only need one fuel totalizer meter if you take fuel from only one
>tank at a time. The fuel quantity meter (and memory) for that tank is
>simply updated as required. I trust in this system, totalizers really
>work well.
>Consider too, that you wouldn't need fuel-level senders or gauges at
>all. Always problematic devices. You also would not need anti-slosh
>electronic filters either. My airplane just got a whole lot lighter!
>
>There are a few practical concerns--how do we know the tank is at the
>level the "gauge" says it is? Well, I always checked it visually with a
>wooden stick anyway. So when tanks are refilled they must be filled to
>the top (ideally) and visually checked. You really wanted the fuel flow
>rate anyway. Not a bad tradeoff.
>
>Eric M. Jones
>
>The whole difference between construction and creation is exactly this:
>that a thing constructed can only be loved after it is constructed;
>but a thing created is loved before it exists.
>- Charles Dickens
>
>
>
>
Message 3
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| Subject: | Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@usjet.net>
>
> The fuel flow totalizer (or whatever--Flowscan?, I believe)
> that talks
> to my VM-1000 is consistently within 0.1 gal and has been
> since 1998. I
> could just tape over my analog guages for all the good that
> they do, I
> mean, my watch is better.....
>
I am using Van's newer style 270 degree arc fuel gauges (I have an
RV6A), together with a totalizer which uses a Floscan transducer. I
find the combination most useful, as the gauges are remarkably accurate
(these indicate gallons in an RV) when in level, reasonably calm air. I
regularly cross check what the gauges indicate for gallonage versus the
totalizer vs time.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 300 hours
www.rvforum.org <<TWO WEEKS, check it out!
www.usfamily.net/web/alexpeterson
Message 4
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| Subject: | Re: Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: Finn Lassen <finnlassen@netzero.net>
Here's what I did in my RV-3 tanks.
I made my own capacitive fuel sensors. Two coaxial alu tubes running
from highest point (outboard rib near filler cap) to lowest point (near
drain). In this way there are no "dead" spots.
The senders are 3/16" alu tubing inside thin-walled 1/2" alu tubing.
Separated by nylon spacers at regular intevals (every 6 inches or so).
Nylon spacers cut from thick nylon tubing found at Home Depot, 3/8" OD,
3/16" ID.
You don't want the spacers to be press-fit on both tubes - fuel needs to
pass. I squeezed the inside tube on each side of spacers to hold
spacers in place.
Capacitance varies from approx 109pF (empty) to approx 175 pF (full), if
I remember correctly.
The capacitance to voltage converters is a simply using the capacitance
to control an op-amp set up as an oscillator (capacitance between ground
and - input) , integrating it (R-C filter), rectifying the signal (diode
and capacitor) and amplifying it. The R-C filter needs to be dimensioned
so the frequencies fall on the 6dB/octave slope.
This doesn't product a linear curve, but I feed this into my home-made
engine monitor where I fix that.
Finn
Message 5
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| Subject: | Small aux battery with Z-13 |
--> AeroElectric-List message posted by: "Fred Stucklen" <wstucklen1@cox.net>
Geoff,
What you are proposing should be OK. It's a manual operation , and the small
battery will not actually start the plane, but that's not it's intension.
What I've done on my new RV-6A is install a second 12 Ah battery that couls
be used in a pinch to start the plane. (Like when you've left the master ON all
night......) I've also powered both electronic ignitions from both batteries
via high current (10A) diodes. There are multiple power paths to each ignition:
from the main bus, from each battery via an oil pressure switch (all diode
coupled). Once the engine is started, turning off the MASTER for either/both batteries
does not stop the engine. Furthermore, the AUX (12 Ah) battery will automatically
disconect itself from the bus if the buss voltage drops below a
preset level (via Bob's ABM circuit). This circuit has an OFF-AUTO-ON selector
switch which can be used to force the AUX battery onto the bus. So it becomes
the primary BUSS battery to start the plane... (assumes that you've left the
main battery OFF because it's dead...).....
If you're interested, I can send you AutoCAD compatible schematics....
Fred Stucklen
RV-6A N926RV
Getting ready to Paint!
Time: 12:02:45 PM PST US
From: Geoff Evans <hellothaimassage@yahoo.com>
Subject: Small aux battery with Z-13
--> AeroElectric-List message posted by: Geoff Evans <hellothaimassage@yahoo.com>
Bob (and anyone else with a useful comment):
I'm considering a Z-13 architecture with an additional small (4.5 AH) battery
to support one side of a dual electronic ignition in the very unlikely event
that the main battery goes inop for whatever reason. I perfer this to two
full-sized batteries because it offers unlimited endurance and it weighs
less.
I'm making an assumption here, and that is that a 4.5 AH battery can support
the operation of either the SD-8 or a standard alternator like the L-40.
If
this is *not* the case (e.g. I should only use a larger battery with the
larger alternator), then the below-proposed system is overly complicated
and
I can slim it down somewhat. I just figured that if I am going to install
a
second small battery just incase the main battery goes inop, it might as
well
be able to make either of my alternators run as well.
Anyway, I propose connecting the 4.5 AH battery directly to the #2 ignition
with a fuesable link. I will also connect it to the always-hot side of the
main battery contactor through a S704-1 relay. I will call the switch for
the
relay the "Aux Battery Bus Tie," and it will be open for starting and closed
for all other operations EXCEPT for when both alternators are inop. In that
case, I'd open the relay to split the batteries so I have more control over
battery endurance.
Additionally, the power to the coil in the relay will come from BOTH
batteries, via diodes. This will allow the relay to be powered from either
battery without allowing current to flow from one battery to the other unless
the relay is actually closed. I think this would be useful in the unlikely
event of a battery-inop situation (which is the only reason I'm installing
a
second small battery in the first place). If the aux battery goes inop, I
can
still use juice from the main battery to hold the relay closed and thereby
power the #2 ign from the main battery. Alternatively, if the main battery
goes inop, I can use juice from the aux battery to hold the relay closed
and
thereby allow the aux battery to be available to support either the L-40
or
the SD-8 alternator.
With this architecture, the only time I'd be without electrical power on
the
e-bus and powering only the #2 ign directly from the aux battery is if the
main battery and both alternators died -- highly unlikely.
Once again, I'm making the assumption that a small battery will support
either the SD-8 or the L-40 alternator. I'm also assuming that it's not "bad
practice" or otherwise unadvisable to power a relay from more than one source
via diodes. Please correct these assumptions if they are wrong.
What do you think?
-Geoff
RV-8
Message 6
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| Subject: | RE: (non?) Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>>the FAA requires that there be a fuel gage but only
>>requires that is shows when the tank is empty.Tom Schiff
---Tom, could you help steer me in the direction where the FAA requires the fuel
tank empty indicator?
What I am proposing is that using only a totalizer may be the best solution. No
"real" fuel gauges at all. The microprocessor can display fuel remaining without
putting some kind of sensor inside the tank(s). Consider--prior to GPS-- inertial
guidance systems could put a ballistic missile to within 10 meters of
a target on the other side of the world. All this with just time and acceleration
totalizers and some gyros. So displaying a fuel level by totalizing how much
gets removed is simple stuff. And I think some people may be doing it now---
From: http://philip.greenspun.com/flying/diamond-da40
>Fuel Totalizer
>The LCD fuel gauges in N505WT are flashy analog/digital affairs, one for each
side. When the tanks are full, the gauges read 17 >gallons although each tank
in fact holds 20 gallons of usable fuel. As you start to burn below 17 gallons
the gauges come alive. >Compared to the float gauges in old-style planes like
Cessnas the gauges are remarkably consistent and stable. Once you've >burned
down below 3 gallons in a tank, the gauge reads "Lo". There is also a "low fuel"
caution light on the annunciator panel. >Generally the gauges on N505WT are
accurate to within 1 gallon, i.e., if they say that the plane has 20 gallons
remaining the plane >will take a top-off of 20 or 21 gallons.
>Experienced pilots know never to trust fuel gauges. What they want is a fuel totalizer.
The VM1000 incorporates one. If you read >the manual you can learn the
unlabeled button functions necessary to tell the VM1000 "this airplane has
a 40-gallon gas tank" and >"I just filled up the gas tank". From there the VM1000
uses its fuel flow meter to calculate how much fuel is remaining. In 505WT
>this number is consistently off by about 5 percent but in a safe direction:
the VM1000 will show 0 gallons remaining when the plane >is still capable of running
for 20 minutes.
Sounds like that's what Diamond does. So the FAA may not require a cork in the
tank. Anybody know for sure?
Regards,
Eric M. Jones
"Most of the time, he's not as bad all the time, as he is some of the time", said
of Tom Bradley, former mayor of L.A.
Message 7
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| Subject: | Re: Small aux battery with Z-13 |
--> AeroElectric-List message posted by: czechsix@juno.com
Geoff,
If I had decided to stick with Z-13, what you are describing in principle
is what I would have done, only I would have added a 1.3 ah aux battery
instead of 4.5 ah. You can get 1.3 ah batteries with faston terminals
for $10 that weigh 1 lb and best of all, fit in Vans standard battery box
along with the Odyssey (I think the PC 680 if I recall correctly...).
This little guy should be big enough at least to bring the SD-8 online
and that's all you really need, anything more is overkill unless I'm
really missing something obvious??
I've gone a step further in my madness and decided that I'm going to
install a single B&C 40 A alternator and one PC 680 and one of the 1.3ah
aux batts isolated by a Schottky diode a la Klaus Savier's schematic to
feed only one electronic ignition. (I'm running dual lightspeeds). Some
may be quick to point out that Klaus recommends a 4.5 ah aux batt, and
that 1.3 ah is not big enough to outlast my tank of gas. Yes this is
correct, but remember that it only matters if I have catastrophic failure
of my main battery. Using flexible battery leads so as not to break the
terminals off, how likely is this? I've accepted that it's possible, but
the odds of it ever happening even if I fly my RV for 10,000 hours is so
unlikely that the aux battery will probably never be more than dead
weight. Remember, if the alternator fails (which is also unlikely if
Bob's assessment of the reliability of B&C's alternators means anything)
I will still have the 16 ah Odyssey battery, which based on my load
analysis should run one of my ignitions and the rest of my e-bus easily
beyond fuel exhaustion. In this scenario I would probably turn OFF the
ignition running on the aux batt to save it as a last ditch reserve in
case my main batt craps out before I want to land. And if my main
battery dies or fails completely, I need to find a place to land within
30-45 mins to be on the safe side. Yes this would be an inconvenience,
but at this point my entire panel would be completely dark and I would
probably be ready to land, even if it's short of my destination.
Inconvenient perhaps? Yes, but worth the trade-off to me in lieu of
carrying an SD-8 around for the rest of my airplane's life that sets my
back $500, adds several more pounds, and will probably never be used. If
I were going to fly it across the Pacific I'd install the SD-8 in a
heartbeat, but I don't see myself flying this aircraft anywhere here in
the U.S where I'm not within 45 min of a usable runway at any given time.
Any flaws in my logic, feel free to point them out....
--Mark Navratil
Cedar Rapids, Iowa
RV-8A finishing....back to the "KISS" principle so I don't backup the
backup for the backup on my ignition system electrical source...
Time: 12:02:45 PM PST US
From: Geoff Evans <hellothaimassage@yahoo.com>
Subject: AeroElectric-List: Small aux battery with Z-13
--> AeroElectric-List message posted by: Geoff Evans
<hellothaimassage@yahoo.com>
Bob (and anyone else with a useful comment):
I'm considering a Z-13 architecture with an additional small (4.5 AH)
battery
to support one side of a dual electronic ignition in the very unlikely
event
that the main battery goes inop for whatever reason. I perfer this to two
full-sized batteries because it offers unlimited endurance and it weighs
less.
I'm making an assumption here, and that is that a 4.5 AH battery can
support
the operation of either the SD-8 or a standard alternator like the L-40.
If
this is *not* the case (e.g. I should only use a larger battery with the
larger alternator), then the below-proposed system is overly complicated
and
I can slim it down somewhat. I just figured that if I am going to install
a
second small battery just incase the main battery goes inop, it might as
well
be able to make either of my alternators run as well.
Anyway, I propose connecting the 4.5 AH battery directly to the #2
ignition
with a fuesable link. I will also connect it to the always-hot side of
the
main battery contactor through a S704-1 relay. I will call the switch for
the
relay the "Aux Battery Bus Tie," and it will be open for starting and
closed
for all other operations EXCEPT for when both alternators are inop. In
that
case, I'd open the relay to split the batteries so I have more control
over
battery endurance.
Additionally, the power to the coil in the relay will come from BOTH
batteries, via diodes. This will allow the relay to be powered from
either
battery without allowing current to flow from one battery to the other
unless
the relay is actually closed. I think this would be useful in the
unlikely
event of a battery-inop situation (which is the only reason I'm
installing a
second small battery in the first place). If the aux battery goes inop, I
can
still use juice from the main battery to hold the relay closed and
thereby
power the #2 ign from the main battery. Alternatively, if the main
battery
goes inop, I can use juice from the aux battery to hold the relay closed
and
thereby allow the aux battery to be available to support either the L-40
or
the SD-8 alternator.
With this architecture, the only time I'd be without electrical power on
the
e-bus and powering only the #2 ign directly from the aux battery is if
the
main battery and both alternators died -- highly unlikely.
Once again, I'm making the assumption that a small battery will support
either the SD-8 or the L-40 alternator. I'm also assuming that it's not
"bad
practice" or otherwise unadvisable to power a relay from more than one
source
via diodes. Please correct these assumptions if they are wrong.
What do you think?
-Geoff
RV-8
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Message 8
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| Subject: | Re: RE: (non?) Microprocessor based Fuel Gauge |
Linearizer
--> AeroElectric-List message posted by: RSwanson <rswan19@comcast.net>
Sec. 23.1337
Powerplant instruments installation.
(a) Instruments and instrument lines.
(1) Each powerplant and auxiliary power unit instrument line must meet the
requirements of Sec. 23.993.
(2) Each line carrying flammable fluids under pressure must--
(i) Have restricting orifices or other safety devices at the source of
pressure to prevent the escape of excessive fluid if the line fails; and
(ii) Be installed and located so that the escape of fluids would not create
a hazard.
(3) Each powerplant and auxiliary power unit instrument that utilizes
flammable fluids must be installed and located so that the escape of fluid
would not create a hazard.
(b) Fuel quantity indicator. There must be a means to indicate to the
flightcrew members the quantity of usable fuel in each tank during flight.
An indicator calibrated in appropriate units and clearly marked to indicate
those units must be used. In addition--
(1) Each fuel quantity indicator must be calibrated to read "zero" during
level flight when the quantity of fuel remaining in the tank is equal to
the unusable fuel supply determined under [Sec. 23.959(a);]
(2) Each exposed sight gauge used as a fuel quantity indicator must be
protected against damage;
(3) Each sight gauge that forms a trap in which water can collect and
freeze must have means to allow drainage on the ground;
(4) There must be a means to indicate the amount of usable fuel in each
tank when the airplane is on the ground (such as by a stick gauge);
(5) Tanks with interconnected outlets and airspaces may be considered as
one tank and need not have separate indicators; and
(6) No fuel quantity indicator is required for an auxiliary tank that is
used only to transfer fuel to other tanks if the relative size of the tank,
the rate of fuel transfer, and operating instructions are adequate to--
(i) Guard against overflow; and
(ii) Give the flight crewmembers prompt warning if transfer is not
proceeding as planned.
(c) Fuel flowmeter system. If a fuel flowmeter system is installed, each
metering component must have a means to by-pass the fuel supply if
malfunctioning of that component severely restricts fuel flow.
----- Original Message -----
From: "Eric M. Jones" <emjones@charter.net>
Subject: AeroElectric-List: RE: (non?) Microprocessor based Fuel Gauge
Linearizer
> --> AeroElectric-List message posted by: "Eric M. Jones"
<emjones@charter.net>
>
> >>the FAA requires that there be a fuel gage but only
> >>requires that is shows when the tank is empty.Tom Schiff
>
> ---Tom, could you help steer me in the direction where the FAA requires
the fuel tank empty indicator?
>
> What I am proposing is that using only a totalizer may be the best
solution. No "real" fuel gauges at all. The microprocessor can display fuel
remaining without putting some kind of sensor inside the tank(s).
Consider--prior to GPS-- inertial guidance systems could put a ballistic
missile to within 10 meters of a target on the other side of the world. All
this with just time and acceleration totalizers and some gyros. So
displaying a fuel level by totalizing how much gets removed is simple
stuff. And I think some people may be doing it now---
>
> From: http://philip.greenspun.com/flying/diamond-da40
> >Fuel Totalizer
> >The LCD fuel gauges in N505WT are flashy analog/digital affairs, one for
each side. When the tanks are full, the gauges read 17 >gallons although
each tank in fact holds 20 gallons of usable fuel. As you start to burn
below 17 gallons the gauges come alive. >Compared to the float gauges in
old-style planes like Cessnas the gauges are remarkably consistent and
stable. Once you've >burned down below 3 gallons in a tank, the gauge reads
"Lo". There is also a "low fuel" caution light on the annunciator panel.
>Generally the gauges on N505WT are accurate to within 1 gallon, i.e., if
they say that the plane has 20 gallons remaining the plane >will take a
top-off of 20 or 21 gallons.
> >Experienced pilots know never to trust fuel gauges. What they want is a
fuel totalizer. The VM1000 incorporates one. If you read >the manual you
can learn the unlabeled button functions necessary to tell the VM1000 "this
airplane has a 40-gallon gas tank" and >"I just filled up the gas tank".
From there the VM1000 uses its fuel flow meter to calculate how much fuel
is remaining. In 505WT >this number is consistently off by about 5 percent
but in a safe direction: the VM1000 will show 0 gallons remaining when the
plane >is still capable of running for 20 minutes.
>
> Sounds like that's what Diamond does. So the FAA may not require a cork
in the tank. Anybody know for sure?
>
> Regards,
>
> Eric M. Jones
>
> "Most of the time, he's not as bad all the time, as he is some of the
time", said of Tom Bradley, former mayor of L.A.
>
>
Message 9
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--> AeroElectric-List message posted by: "Gary Casey" <glcasey@adelphia.net>
<<Anyway, I propose connecting the 4.5 AH battery directly to the #2
ignition
with a fusible link. I will also connect it to the always-hot side of the
main battery contactor through a S704-1 relay. I will call the switch for
the
relay the "Aux Battery Bus Tie," and it will be open for starting and closed
for all other operations EXCEPT for when both alternators are inop. In that
case, I'd open the relay to split the batteries so I have more control over
battery endurance.>>
I'm wondering why you would want to feed the aux battery from the main
system. The reason I ask is that I'm contemplating a dual batter/dual
alternator system with a small second battery charged by a small alternator
that powers only the second Engine Management System and second fuel pump.
That way it is an independent engine support system not in any way connected
to the "main" system. The second alternator goes away it is time to land,
not an excuse to keep going indefinitely. If I planned to be several hours
away from the nearest airport I might have a different opinion. My theory
now is to keep it as simple as possible and keep the engine running without
human intervention. One likely scenario in your system might be that the
main alternator fails (certainly possible) and you run the main battery down
by mistakenly not shedding enough load. You are about to land and now you
need to operate the landing lights/landing gear/flap motor or whatever, so
you decide to connect the two systems. The large load pulls the second
system down and the engine stops. Keeping the two systems separate
essentially protects the engine from the pilot.
Gary Casey
Message 10
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| Subject: | Re: RE: (non?) Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Cy Galley" <cgalley@qcbc.org>
(1) Each fuel quantity indicator must be calibrated to read "zero" during
level flight when the quantity of fuel remaining in the tank is equal to the
unusable fuel supply determined under 23.959(a);
23.1553 Fuel quantity indicator.
A red radial line must be marked on each indicator at the calibrated zero
reading, as specified in 23.1337(b)(1).
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cgalley@qcbc.org or experimenter@eaa.org
Always looking for articles for the Experimenter
----- Original Message -----
From: "Eric M. Jones" <emjones@charter.net>
Subject: AeroElectric-List: RE: (non?) Microprocessor based Fuel Gauge
Linearizer
> --> AeroElectric-List message posted by: "Eric M. Jones"
<emjones@charter.net>
>
> >>the FAA requires that there be a fuel gage but only
> >>requires that is shows when the tank is empty.Tom Schiff
>
> ---Tom, could you help steer me in the direction where the FAA requires
the fuel tank empty indicator?
>
> What I am proposing is that using only a totalizer may be the best
solution. No "real" fuel gauges at all. The microprocessor can display fuel
remaining without putting some kind of sensor inside the tank(s).
Consider--prior to GPS-- inertial guidance systems could put a ballistic
missile to within 10 meters of a target on the other side of the world. All
this with just time and acceleration totalizers and some gyros. So
displaying a fuel level by totalizing how much gets removed is simple stuff.
And I think some people may be doing it now---
>
> From: http://philip.greenspun.com/flying/diamond-da40
> >Fuel Totalizer
> >The LCD fuel gauges in N505WT are flashy analog/digital affairs, one for
each side. When the tanks are full, the gauges read 17 >gallons although
each tank in fact holds 20 gallons of usable fuel. As you start to burn
below 17 gallons the gauges come alive. >Compared to the float gauges in
old-style planes like Cessnas the gauges are remarkably consistent and
stable. Once you've >burned down below 3 gallons in a tank, the gauge reads
"Lo". There is also a "low fuel" caution light on the annunciator panel.
>Generally the gauges on N505WT are accurate to within 1 gallon, i.e., if
they say that the plane has 20 gallons remaining the plane >will take a
top-off of 20 or 21 gallons.
> >Experienced pilots know never to trust fuel gauges. What they want is a
fuel totalizer. The VM1000 incorporates one. If you read >the manual you can
learn the unlabeled button functions necessary to tell the VM1000 "this
airplane has a 40-gallon gas tank" and >"I just filled up the gas tank".
From there the VM1000 uses its fuel flow meter to calculate how much fuel is
remaining. In 505WT >this number is consistently off by about 5 percent but
in a safe direction: the VM1000 will show 0 gallons remaining when the plane
>is still capable of running for 20 minutes.
>
> Sounds like that's what Diamond does. So the FAA may not require a cork in
the tank. Anybody know for sure?
>
> Regards,
>
> Eric M. Jones
>
> "Most of the time, he's not as bad all the time, as he is some of the
time", said of Tom Bradley, former mayor of L.A.
>
>
Message 11
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| Subject: | RE: (non?) Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Tom Schiff" <tomschiff@attbi.com>
It is part of the minimum instrumentation that is required for VFR
flight for piston aircraft.
Quoting from FAR 91.205(b) it is:
1. Airspeed indicator
2. Altimeter
3. Magnetic direction indicator.
4. Tachometer for each engine.
5. Oil pressure gauge for each engine using pressure system
6. Temperature gauge for each liquid-cooled engine.
7. Oil temperature gauge for each air-cooled engine.
8. Manifold pressure gauge for each altitude engine.
9. Fuel gauge indicating the quantity of fuel in each tank.
10. Landing gear position indicator, if the aircraft as a retractable
landing gear.
There is more to section 91.205(b) but this discussion is about
instrumentation.
True this is for certified aircraft and you could argue that you don't
need it for an Experimental. The question is could you get the inspector
to sign off the finished aircraft without a fuel quantity indicator. I
cannot think of a valid reason not to have one. That said, for me there
is a possibility that I could input the wrong value into the fuel
totalizer at startup and then my fuel quantity would be wrong. In my 150
I depend more on the fuel remaining on the fuel totalizer than the fuel
gages, but I wouldn't have a plane without some form of fuel quantity
indicator. Running out of fuel is too unpleasant an event. When I am
flying at start up I put the time that I must be on the ground based on
my fuel calculations. It is part of my scan to be checking that. I do
this for every flight even a quick three passes around the pattern. So I
am not doing three cross checks of fuel quantity. Gages, fuel flow, and
calculation.
I just attended a seminar where a report was presented of a fuel
starvation accident. The pilot was mature, safety conscious, high time,
instrument rated, hundreds of hours in the accident aircraft. He had a
milk run that he flew on the average of 4 times a month. Point A to
point B on the left tank. Return from point B to point A on the right
tank. The club had installed a Garmin 430 so he decided on the return
flight to shoot some approaches. Fuel calculations showed that he had
the fuel to do it. The totalizer showed he had the fuel. The fuel gages
were working but he had gotten out of the habit of checking them. He ran
out of fuel on the right tank and panicked when the engine stopped. He
ran an absolutely by the book total engine failure procedure including
touchdown. He was slightly injured. The plane was totaled. There was 25
gallons of gas in the left tank. Now if he had been watching the gas
gages this would not have happened.
A few light sensor fuel level indicators are too cheap in relationship
to the cost of an entire aircraft not to include them. At least one per
tank that would warn of less than 1/4 of a tank as is done in some
motorcycles
One thing to notice is that FAR 91.205(b) requires a fuel indicator for
EACH tank. So my 150 has two fuel gages even though the tanks are
plumbed together.
BTW I set up my fuel totalizer so that when it reads zero I am at the
unusable reserve. My gages in the 150 are still (correctly) showing
about 1/8th of a tank.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric
M. Jones
Subject: AeroElectric-List: RE: (non?) Microprocessor based Fuel Gauge
Linearizer
--> AeroElectric-List message posted by: "Eric M. Jones"
<emjones@charter.net>
>>the FAA requires that there be a fuel gage but only
>>requires that is shows when the tank is empty.Tom Schiff
---Tom, could you help steer me in the direction where the FAA requires
the fuel tank empty indicator?
What I am proposing is that using only a totalizer may be the best
solution. No "real" fuel gauges at all. The microprocessor can display
fuel remaining without putting some kind of sensor inside the tank(s).
Consider--prior to GPS-- inertial guidance systems could put a ballistic
missile to within 10 meters of a target on the other side of the world.
All this with just time and acceleration totalizers and some gyros. So
displaying a fuel level by totalizing how much gets removed is simple
stuff. And I think some people may be doing it now---
From: http://philip.greenspun.com/flying/diamond-da40
>Fuel Totalizer
>The LCD fuel gauges in N505WT are flashy analog/digital affairs, one
for each side. When the tanks are full, the gauges read 17 >gallons
although each tank in fact holds 20 gallons of usable fuel. As you start
to burn below 17 gallons the gauges come alive. >Compared to the float
gauges in old-style planes like Cessnas the gauges are remarkably
consistent and stable. Once you've >burned down below 3 gallons in a
tank, the gauge reads "Lo". There is also a "low fuel" caution light on
the annunciator panel. >Generally the gauges on N505WT are accurate to
within 1 gallon, i.e., if they say that the plane has 20 gallons
remaining the plane >will take a top-off of 20 or 21 gallons.
>Experienced pilots know never to trust fuel gauges. What they want is a
fuel totalizer. The VM1000 incorporates one. If you read >the manual you
can learn the unlabeled button functions necessary to tell the VM1000
"this airplane has a 40-gallon gas tank" and >"I just filled up the gas
tank". From there the VM1000 uses its fuel flow meter to calculate how
much fuel is remaining. In 505WT >this number is consistently off by
about 5 percent but in a safe direction: the VM1000 will show 0 gallons
remaining when the plane >is still capable of running for 20 minutes.
Sounds like that's what Diamond does. So the FAA may not require a cork
in the tank. Anybody know for sure?
Regards,
Eric M. Jones
"Most of the time, he's not as bad all the time, as he is some of the
time", said of Tom Bradley, former mayor of L.A.
Message 12
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|
| Subject: | Re: RE: (non?) Microprocessor based Fuel Gauge |
Linearizer
--> AeroElectric-List message posted by: Charlie & Tupper England <cengland@netdoor.com>
Eric M. Jones wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>
>
>>>the FAA requires that there be a fuel gage but only
>>>requires that is shows when the tank is empty.Tom Schiff
>>>
>>>
>
>---Tom, could you help steer me in the direction where the FAA requires the fuel
tank empty indicator?
>
>What I am proposing is that using only a totalizer may be the best solution. No
"real" fuel gauges at all. The microprocessor can display fuel remaining without
putting some kind of sensor inside the tank(s). Consider--prior to GPS--
inertial guidance systems could put a ballistic missile to within 10 meters of
a target on the other side of the world. All this with just time and acceleration
totalizers and some gyros. So displaying a fuel level by totalizing how much
gets removed is simple stuff. And I think some people may be doing it now---
>
<snipped>
One factor in favor of having an 'empty' indicator in addition to a
totalizer is that the induction system isn't the only way for fuel to
leave a tank. Leaks, forgotten or failed caps, mis-fueling by a line
person, etc can lead to fuel exhaustion that won't be detected by a
totalizer. This might have been the FAA 'logic' in requiring that fuel
indicators accurately indicate 'empty'.
I agree that a totalizer is much more useful than a quantity guage, but
the guage is a good backup for the totalizer.
Charlie
Message 13
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| Subject: | Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Tom Schiff" <tomschiff@attbi.com>
Read the incident that I mention in my other reply.
Also I have read about a few accidents where the fuel drains started
leaking in flight, or where the gas caps were left off, or the wrong dip
stick was used and the initial calculation was wrong.
One of the nice things with a light sensor fuel gage is that the 1/4
full sensor can trigger an audible or visual alarm.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Boyd
C. Braem
Subject: Re: AeroElectric-List: Microprocessor based Fuel Gauge
Linearizer
--> AeroElectric-List message posted by: "Boyd C. Braem"
<bcbraem@comcast.net>
The fuel flow totalizer (or whatever--Flowscan?, I believe) that talks
to my VM-1000 is consistently within 0.1 gal and has been since 1998. I
could just tape over my analog guages for all the good that they do, I
mean, my watch is better.....
Tom Schiff wrote:
>--> AeroElectric-List message posted by: "Tom Schiff"
<tomschiff@attbi.com>
>
>The problem is that the FAA requires that there be a fuel gage but only
>requires that is shows when the tank is empty. I have been using a fuel
>flow in my C-150 for several months. I have been updating the amount
>remaining every time I fill by the exact amount that I have filled. It
>has been agreeing with the amount determined by sticking the tanks.
>After many fills and over 100 gallons of fuel burned it is still within
>.2 gallons. So you could probably get away with a fuel gage that is in
>reality a fuel flow gage but if you got caught you would be in trouble.
>
>My ideal fuel gage would be several sensors of the type where a led
>shines a light through a prism. When the prism is submerged in gas the
>light shines on a photo sensor and indicates that the sensor is below
>the level of the fuel. The sensors would be at various levels in each
>tank an they would light two sets of led indicators on in the cockpit
>and another aggacent to the filler port. I this way I would know when I
>was about to overfill the tanks. I saw a Money that had a fuel gage
next
>to the filler port and that is where I got the idea from. Because you
>have absolutle freedom where you place the sensors you wouldn't have to
>worry about the non linearitys of flat tanks that are inclined at an
>angle
>
>-----Original Message-----
>From: owner-aeroelectric-list-server@matronics.com
>[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric
>M. Jones
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Microprocessor based Fuel Gauge Linearizer
>
>--> AeroElectric-List message posted by: "Eric M. Jones"
><emjones@charter.net>
>
>Neil Hulin's comment about using a fuel totalizer instead of a fuel
>gauge linearizer has been burning a hole in my brain. I believe he is
>right....
>
>Here's the deal--
>
>You only need one fuel totalizer meter if you take fuel from only one
>tank at a time. The fuel quantity meter (and memory) for that tank is
>simply updated as required. I trust in this system, totalizers really
>work well.
>Consider too, that you wouldn't need fuel-level senders or gauges at
>all. Always problematic devices. You also would not need anti-slosh
>electronic filters either. My airplane just got a whole lot lighter!
>
>There are a few practical concerns--how do we know the tank is at the
>level the "gauge" says it is? Well, I always checked it visually with a
>wooden stick anyway. So when tanks are refilled they must be filled to
>the top (ideally) and visually checked. You really wanted the fuel flow
>rate anyway. Not a bad tradeoff.
>
>Eric M. Jones
>
>The whole difference between construction and creation is exactly this:
>that a thing constructed can only be loved after it is constructed;
>but a thing created is loved before it exists.
>- Charles Dickens
>
>
>
>
Message 14
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| Subject: | Microprocessor based Fuel Gauge Linearizer |
--> AeroElectric-List message posted by: "Tom Schiff" <tomschiff@attbi.com>
I have heard that capacitive gages will not work with Jet-A because
there is some water dissolved in the fuel which gives it some
conductivity. You may be able to use insulated sensors.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Wolfgang Trinks
Subject: Re: AeroElectric-List: Microprocessor based Fuel Gauge
Linearizer
--> AeroElectric-List message posted by: "Wolfgang Trinks"
<Wolfgang.Trinks@flugbereitschaft.com>
I agree that a fuel totalizer in combination with a fuel gauge with a
certain tolerance but precisly showing low fuel situation is a
reasonable
way to go.
But there are also others:
I did linearize a the fuel gauge once on my daycruiser(boat). What
appeared
to be a weekend programming job on a 80C515 turned into a small >Joint
Strike Fighter< project.
First of all, giving the situation of flat tanks with irregular shapes
you
have to determine the funtion of fuel volume versus measuring height of
your
sensor at a given sensor position mathematicly using linear algebra.
This is
a must.
As this can turn into a nightmare espacially if the tank is inclined
during
climb or decent there is a way making things easier(You can neglect bank
because a plane is flown coordinated 99% of the fight time).
Devide your tank in your mind into boxes and put a sensor in the middle
of
each box. The smaller the boxes the lower is the influence of the
incline
and the more precisly you can determine the volume versus measuring
height
by simple trigometrie. The sum of all sensor added one by one will be
the
full tank reading where the max value of every sensor equals the
contribution of his box to the total volume. The more boxes, the more
precise and more expensive. So there must be a compromise, but this is
strongly dependent on the shape of the tank.
Anyway when I did this I programmed my f(fuel) in a pascal programm
where I
simulated the different incline and was able to play arround with the
number
and position of the virtual boxes. It turned out that I could come below
1%
error with 3 sensors on a tank measuring 80cm x 50cm x 180cm in angles
up to
15 degree in most unfavourable axis. This was a quite positive
experiance. I
think also for a plane with a LL100 grade burning engine 15 degree of
continious pitch up during climb should be far enough.
If you do this you have got the problem on the root and depending on the
type of sensor there will be hardly any linearizing nessecary.
On my boat I used VDO linear resistence floaters and the results where
perfect.
If I would have to do it on a plane today I would use a capacitive
system as
sensors because you could very easily build your own sensors (basic
machining required) and finetune the sensors to the tank shape.It also
shows
the weight of fuel in the tanks which is the correct measure for your
endurance(ok, this is academic with those tiny volumes).
To get a feeling for all this just look what the big ones are doing if
they
need fuel indicators that are serious(Cessna 340,414, King Air,
Citation,
all big jets)
Wolfgang...
----- Original Message -----
From: "Tom Schiff" <tomschiff@attbi.com>
Subject: RE: AeroElectric-List: Microprocessor based Fuel Gauge
Linearizer
> --> AeroElectric-List message posted by: "Tom Schiff"
<tomschiff@attbi.com>
>
> The problem is that the FAA requires that there be a fuel gage but
only
> requires that is shows when the tank is empty. I have been using a
fuel
> flow in my C-150 for several months. I have been updating the amount
> remaining every time I fill by the exact amount that I have filled. It
> has been agreeing with the amount determined by sticking the tanks.
> After many fills and over 100 gallons of fuel burned it is still
within
> .2 gallons. So you could probably get away with a fuel gage that is in
> reality a fuel flow gage but if you got caught you would be in
trouble.
>
> My ideal fuel gage would be several sensors of the type where a led
> shines a light through a prism. When the prism is submerged in gas the
> light shines on a photo sensor and indicates that the sensor is below
> the level of the fuel. The sensors would be at various levels in each
> tank an they would light two sets of led indicators on in the cockpit
> and another aggacent to the filler port. I this way I would know when
I
> was about to overfill the tanks. I saw a Money that had a fuel gage
next
> to the filler port and that is where I got the idea from. Because you
> have absolutle freedom where you place the sensors you wouldn't have
to
> worry about the non linearitys of flat tanks that are inclined at an
> angle
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Eric
> M. Jones
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Microprocessor based Fuel Gauge Linearizer
>
> --> AeroElectric-List message posted by: "Eric M. Jones"
> <emjones@charter.net>
>
> Neil Hulin's comment about using a fuel totalizer instead of a fuel
> gauge linearizer has been burning a hole in my brain. I believe he is
> right....
>
> Here's the deal--
>
> You only need one fuel totalizer meter if you take fuel from only one
> tank at a time. The fuel quantity meter (and memory) for that tank is
> simply updated as required. I trust in this system, totalizers really
> work well.
> Consider too, that you wouldn't need fuel-level senders or gauges at
> all. Always problematic devices. You also would not need anti-slosh
> electronic filters either. My airplane just got a whole lot lighter!
>
> There are a few practical concerns--how do we know the tank is at the
> level the "gauge" says it is? Well, I always checked it visually with
a
> wooden stick anyway. So when tanks are refilled they must be filled to
> the top (ideally) and visually checked. You really wanted the fuel
flow
> rate anyway. Not a bad tradeoff.
>
> Eric M. Jones
>
> The whole difference between construction and creation is exactly
this:
> that a thing constructed can only be loved after it is constructed;
> but a thing created is loved before it exists.
> - Charles Dickens
>
>
Message 15
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| Subject: | Headphone noise on transmit |
--> AeroElectric-List message posted by: Duncan McBride <duncanmcbride@comcast.net>
I've been fussing with what seemed to be ignition or alternator noise in my radio
when I pushed the PTT on my Microair 760. I posted to the list a while back,
and tried a different power source and a different antenna. The noise was
there even when powered from a separate battery. Here is the thing: the noise
is a loud hiss that I only hear when transmitting. Reception is clear as a
bell. What I found out today is that my transmissions are clear as well. I
spoke with another pilot sharing the pattern as we self-announced our way into
Avon Park this morning and he said my signal was loud and clear, no hiss or any
noise. It seems the noise is only coming out my headphones. I experimented
and found the noise is independent of the radio volume but decreases if I turn
down the headphones, so I can mitigate it somewhat by turning down the headphones
and turning up the radio volume. These are twenty year old David Clark
H10-80 'phones they don't make anymore. I haven't tried any
t could they be the problem?
Message 16
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| Subject: | Re: Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Paul McAllister" <paul.mcallister@qia.net>
Hi Bob,
I purchased 50 sockets, but to no avail, well almost. They fitted the 37
pin D Style connector on the SL70 transponder, but not the 37 pin connector
for the GX60.
The sockets wouldn't slide all the way in and when I examined them closely
the sockets that did fit had a split on the front and the barrel was about
10 thou smaller. I found that the 15 pin connector on the GX60 and the 37
pin on the Narco Nav 122 had the same problem.
Any idea on where to get this style of pin? I can send you an example if it
would help.
Thanks, Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Source for Pins & Extraction tools
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 01:33 PM 5/11/2003 -0500, you wrote:
> >--> AeroElectric-List message posted by: "Paul McAllister"
> ><paul.mcallister@qia.net>
> >
> >Hi all,
> >
> >I am approaching the stage where I will be wiring up my UPS GX60 Nav/Com
&
> >SL 70 transponder. The units come supplied with 37 pin D style
connectors
> >and I am seeking some advice.
> >
> >Where can I purchase a suitable crimping tool, insertion/extraction tool
> >and some pins & sockets.
>
>
> See:
>
> http://www.aeroelectric.com/Catalog/tools/tools.html#rct-3
> http://www.aeroelectric.com/Catalog/tools/tools.html#dse-1
> http://www.aeroelectric.com/Catalog/connect/connect.html#S604
> http://www.aeroelectric.com/Catalog/BCcatalog.html
>
>
> > I would be interested to know what size wire do people typically use
in
> > these pins to ensure a good crimp
>
> 24-20 AWG wire works well in these pins. 20AWG for
> power/ground and 22AWG for everything else is
> good . . .
>
>
> Bob . . .
>
>
> --------------------------------------------
> ( Knowing about a thing is different than )
> ( understanding it. One can know a lot )
> ( and still understand nothing. )
> ( C.F. Kettering )
> --------------------------------------------
>
>
Message 17
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| Subject: | Re: Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Bill Steer" <bsteer@gwi.net>
----- Original Message -----
From: "Paul McAllister" <paul.mcallister@qia.net>
Subject: Re: AeroElectric-List: Source for Pins & Extraction tools
> --> AeroElectric-List message posted by: "Paul McAllister"
<paul.mcallister@qia.net>
>
> Hi Bob,
>
> I purchased 50 sockets, but to no avail, well almost. They fitted the 37
> pin D Style connector on the SL70 transponder, but not the 37 pin connector
> for the GX60.
>
> The sockets wouldn't slide all the way in and when I examined them closely
> the sockets that did fit had a split on the front and the barrel was about
> 10 thou smaller. I found that the 15 pin connector on the GX60 and the 37
> pin on the Narco Nav 122 had the same problem.
>
> Any idea on where to get this style of pin? I can send you an example if it
> would help.
>
> Thanks, Paul
>
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: Source for Pins & Extraction tools
>
>
> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
> >
> > At 01:33 PM 5/11/2003 -0500, you wrote:
> > >--> AeroElectric-List message posted by: "Paul McAllister"
> > ><paul.mcallister@qia.net>
> > >
> > >Hi all,
> > >
> > >I am approaching the stage where I will be wiring up my UPS GX60 Nav/Com
> &
> > >SL 70 transponder. The units come supplied with 37 pin D style
> connectors
> > >and I am seeking some advice.
> > >
> > >Where can I purchase a suitable crimping tool, insertion/extraction tool
> > >and some pins & sockets.
> >
> >
> > See:
> >
> > http://www.aeroelectric.com/Catalog/tools/tools.html#rct-3
> > http://www.aeroelectric.com/Catalog/tools/tools.html#dse-1
> > http://www.aeroelectric.com/Catalog/connect/connect.html#S604
> > http://www.aeroelectric.com/Catalog/BCcatalog.html
> >
> >
> > > I would be interested to know what size wire do people typically use
> in
> > > these pins to ensure a good crimp
> >
> > 24-20 AWG wire works well in these pins. 20AWG for
> > power/ground and 22AWG for everything else is
> > good . . .
> >
> >
> > Bob . . .
> >
> >
> > --------------------------------------------
> > ( Knowing about a thing is different than )
> > ( understanding it. One can know a lot )
> > ( and still understand nothing. )
> > ( C.F. Kettering )
> > --------------------------------------------
> >
> >
>
>
Message 18
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| Subject: | Unnecessary fuel gauges!!!? |
--> AeroElectric-List message posted by: "Rob W M Shipley" <Rob@RobsGlass.com>
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
Neil Hulin's comment about using a fuel totalizer instead of a fuel gauge linearizer
has been burning a hole in my brain. I believe he is right....
Here's the deal--
You only need one fuel totalizer meter if you take fuel from only one tank at a
time. The fuel quantity meter (and memory) for that tank is simply updated as
required. I trust in this system, totalizers really work well.
Consider too, that you wouldn't need fuel-level senders or gauges at all. Always
problematic devices. You also would not need anti-slosh electronic filters
either. My airplane just got a whole lot lighter!
There are a few practical concerns--how do we know the tank is at the level the
"gauge" says it is? Well, I always checked it visually with a wooden stick anyway.
So when tanks are refilled they must be filled to the top (ideally) and
visually checked. You really wanted the fuel flow rate anyway. Not a bad tradeoff.
This is a nice idea but what happens if fuel is lost from the system anywhere
on the tank side of totalizer sender? e.g. loose fuel cap, cracked pipe etc.
Now your totalizer is telling you that full fuel, less that burned in the engine,
remains. Not!
Also I may be wrong but I have this hazy memory of the Feds, (always here to help),
requiring gauges ......
Don't get me wrong. I think totalizers are a terrific idea but a pair of steam
fuel gauges a watch and knowledge of approximate fuel burn make a terrific cross
check with each other to confirm what you actually have to get you home.
Bit like doing a mental approximation of a problem to check you hit the right
buttons on the calculator or in this case that your totalizer figures are valid.
Fly safe
Rob
Rob W M Shipley
RV9A N919RV Fuselage - now a canoe!!!
Message 19
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| Subject: | : The value talking about simple-ideas . . . |
--> AeroElectric-List message posted by: "Rob W M Shipley" <Rob@RobsGlass.com>
I would like to most emphatically endorse Phil's email thanking especially Bob
and also the other technically able contributors.
The single invaluable benefit I have got from you all is an albeit shaky grip on
how to look at a problem. It's the logic of how and why that is so valuable.
Not to devalue the tech stuff, help with this is vital too but the mental light
bulb that goes on when you understand why doing 'this' and not 'that' is
the safest and most efficient method is (like my wife's Visa purchases) absolutely
priceless.
Thanks again guys.
Rob
Rob W M Shipley
RV9A N919RV Fuselage - now a canoe!!!
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