Today's Message Index:
----------------------
1. 02:03 AM - Zeftronics G1200N (Peter W Johnson)
2. 05:04 AM - Re: Zeftronics G1200N (BobsV35B@aol.com)
3. 06:25 AM - Re: Designing a circuit question (user9253)
4. 06:54 AM - GNC300 XL (jtortho@aol.com)
5. 07:21 AM - NiZn Batteries (Ron Quillin)
6. 07:26 AM - Re: Zeftronics G1200N (Peter W Johnson)
7. 07:44 AM - Re: Accurate Altitude and Airspeed (Sam Hoskins)
8. 08:04 AM - Re: Re: Designing a circuit question (Doug Ilg)
9. 08:06 AM - Re: Accurate Altitude and Airspeed (Floyd Wilkes)
10. 08:43 AM - Re: Accurate Altitude and Airspeed (Kevin Horton)
11. 08:54 AM - Re: Crowbar OV module part (J. Mcculley)
12. 10:00 AM - Re: GNC300 XL (Charlie England)
13. 10:23 AM - Re: Zeftronics G1200N (BobsV35B@aol.com)
14. 12:14 PM - Re: Designing a circuit question (Robert L. Nuckolls, III)
15. 01:05 PM - how to wire an electret microphone (Bill Bradburry)
16. 03:46 PM - Re: Re: Designing a circuit question (Dennis & Anne Glaeser)
17. 06:35 PM - Re: Re: Re: Designing a circuit question (Doug Ilg)
18. 06:49 PM - Re: how to wire an electret microphone (David LLoyd)
19. 07:38 PM - Re: how to wire an electret microphone ()
20. 07:38 PM - B & C Specialties Warning Light- Would Like to Dim (Bob Falstad)
21. 08:35 PM - Re: how to wire an electret microphone (Ron Quillin)
Message 1
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| Subject: | Zeftronics G1200N |
Hi Guys,
I am presently trouble shooting a newly installed regulator on an O-200.
I have measured all the resistances and all seem OK.
When I connect everything up and turn on the Bat and Fld switches (engine
off) I get the three lights, GO, VR, and CL all on but the CL light is red
not green. Is this a problem?
Presently the Gen Out Light doesn't seem to go out until around 1800 rpm. I
assume from the zeftronics documents that this should go out at between 1100
rpm and 1400 rpm.
Any advice would be good.
Cheers
Peter
Wonthaggi Australia
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| Subject: | Re: Zeftronics G1200N |
Good Morning Peter,
A couple of years ago I was having trouble getting a Zeftronics unit to
operate the way I thought it should. Just as you have done, I measured the
resistance of various components and all checked out fine. When I called
Zeftronics, they told me to check the actual voltage while the system was
operating. I attached appropriate wiring to the points they suggested so
that I
could get the data they wanted with the engine running. In fact, I checked
it in flight.
I found that even though several components checked out OK with my Ohmmete
r
when static, there were inappropriate voltage drops when in operation. I
changed a circuit breaker and a field switch in the circuit and all my
problems went away. That may have nothing to do with your problem, but it
taught
me that the system needs to be checked when it is under load.
For What It Is Worth, I have installed Zeftronics Alternator Control Units
in three airplanes thus far and have been very pleased with them all. The
folks at the factory have answered my questions patiently and fully.
Happy Skies,
Old Bob
In a message dated 4/18/2010 4:04:44 A.M. Central Daylight Time,
vk3eka@bigpond.net.au writes:
Hi Guys,
I am presently trouble shooting a newly installed regulator on an O-200.
I have measured all the resistance and all seem OK.
When I connect everything up and turn on the Bat and Fld switches (engine
off) I get the three lights, GO, VR, and CL all on but the CL light is re
d
not green. Is this a problem?
Presently the Gen Out Light doesn=99t seem to go out until around
1800 rpm.
I assume from the zeftronics documents that this should go out at between
1100 rpm and 1400 rpm.
Any advice would be good.
Cheers
Peter
Wonthaggi Australia
========================
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========================
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============
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========================
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Message 3
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| Subject: | Re: Designing a circuit question |
Dennis,
How about this circuit designed by Bob N?
http://www.aeroelectric.com/articles/Failure_Detection_and_Annunciation.pdf
You would have to experiment with the number of turns of wire to wrap around the
reed relay. I have reed switches and can bring one to the EAA meeting if you
need it.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=294643#294643
Message 4
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I realize this is more avionics then electrics, but this place is my prim
ary resource.
After a small building hiatus, I am back on wiring my panel.
the 300 xl has MIC Audio hi and Low as possible inputs.
The AVCOM AC6PA intercom has a MIC to Radio output, but I cannot find:
output levels at that MIC to radio connector in the AVCOM book.
input levels listed in the 300XL installation for either input.
Anybody have the answer or an additional resource to review?
Jim Timoney
Searey 80% done, 90% to go
Message 5
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I see this morning Amazon has a gold box special on Powergenix 1.6V
rechargeable batteries.
http://www.amazon.com/gp/goldbox/ref=cs_top_nav_gb27
A recharger and 4 AA for $15.
http://www.powergenix.com/products.php
Their faq
http://www.powergenix.com/faq.php
Is pretty generic, but does have a few tidbits. From reading the list, I
should know what self-discharge rates are for other batteries, and my gray
is showing, but they cite *PowerGenix batteries have a self-discharge rate
equal of approximately 8 percent per month at room temperature. This is
comparable to other rechargeable batteries. *
I'm tempted to try them out for cameras and GPS units.
Anyone with any experience?
I'm sure there will be comments...
Ron Q.
Message 6
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| Subject: | Zeftronics G1200N |
Bob,
Thanks, did you ever get a copy of the fault light codes?
Looks like I=99ll have to do a little more testing.
Cheers
Peter
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
BobsV35B@aol.com
Sent: Sunday, 18 April 2010 10:02 PM
Subject: Re: AeroElectric-List: Zeftronics G1200N
Good Morning Peter,
A couple of years ago I was having trouble getting a Zeftronics unit to
operate the way I thought it should. Just as you have done, I measured
the resistance of various components and all checked out fine. When I
called Zeftronics, they told me to check the actual voltage while the
system was operating. I attached appropriate wiring to the points they
suggested so that I could get the data they wanted with the engine
running. In fact, I checked it in flight.
I found that even though several components checked out OK with my
Ohmmeter when static, there were inappropriate voltage drops when in
operation. I changed a circuit breaker and a field switch in the circuit
and all my problems went away. That may have nothing to do with your
problem, but it taught me that the system needs to be checked when it is
under load.
For What It Is Worth, I have installed Zeftronics Alternator Control
Units in three airplanes thus far and have been very pleased with them
all. The folks at the factory have answered my questions patiently and
fully.
Happy Skies,
Old Bob
In a message dated 4/18/2010 4:04:44 A.M. Central Daylight Time,
vk3eka@bigpond.net.au writes:
Hi Guys,
I am presently trouble shooting a newly installed regulator on an O-200.
I have measured all the resistance and all seem OK.
When I connect everything up and turn on the Bat and Fld switches
(engine off) I get the three lights, GO, VR, and CL all on but the CL
light is red not green. Is this a problem?
Presently the Gen Out Light doesn=99t seem to go out until around
1800 rpm. I assume from the zeftronics documents that this should go out
at between 1100 rpm and 1400 rpm.
Any advice would be good.
Cheers
Peter
Wonthaggi Australia
List
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.
matronics.com/Navigator?AeroElectric-List
ms.matronics.com/">http://forums.matronics.com
tp://www.matronics.com/contribution">http://www.matronics.com/contributio
n
Message 7
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| Subject: | Re: Accurate Altitude and Airspeed |
This is great information about the static ports. I recently switched from
steam gauges to a Dynon FlightDek. One of the neatest features is the winds
aloft display. Unfortunately, I figured out that it was pretty inaccurate.
One day, I went up and flew four headings and this is what got:
Compass Wind Direction Wind Speed
360 242 20
270 334 18
180 251 31
090 271 08
This told me the display was pretty much worthless. I posted s couple of
notes about it on the Dynon factory forum and was told to look after my
static ports, but no indication how to go about it.
I will definitely be investigating the wedges at the static ports.
Thanks.
Sam Hoskins
Murphysboro, IL
On Thu, Apr 15, 2010 at 5:06 PM, <bakerocb@cox.net> wrote:
>
> 4/15/2010
>
> Hello Mike, You wrote: "Not sure why this (altitude variation with
> airspeed)
> would be, or more importantly, how to fix it."
>
> Hello Bernie, You wrote: "There didn't seem to be any theory behind it."
>
> This is not a very rare or mysterious phenomena. Inaccurate airspeed
> indications can be caused by inaccurate dynamic and static air pressure
> forces. Inaccurate altitude indications can be caused by inaccurate static
> pressure forces.
>
> AIRSPEED. Let's talk about inaccurate airspeed measurements first. An
> airspeed indicator is a balancing mechanism. It balances the difference
> between a force created by dynamic air pressure and a force created by
> static air pressure. The force from the dynamic air pressure is the result
> of the forward movement of the airplane. The faster the airplane moves the
> greater the force exerted.
>
> In order to get an accurate measure of that dynamic force one needs to
> accurately sense the free stream dynamic air pressure and send it to the
> airspeed indicator via leak and kink free tubing. That means sensing the
> air
> movement in the actual direction that the airplane is moving and having
> that
> air movement not affected by some local air flow direction change caused by
> the airframe itself. This is why you sometimes see flight test airplanes
> with a long boom sticking out forward with a small vane mechanism on the
> front of it. This boom and vane mechanism, along with connecting tubing, is
> a pitot tube system intended to accurately measure the force from the free
> stream dynamic air pressure without any inaccuracies introduced by local
> airframe air flow. See Note One below.
>
> So much for the dynamic force side of the airspeed indicator balancing act,
> what about the static force side? An accurate static force is provided by a
> static port ideally located somewhere on the airframe such that it is
> measuring the true static air pressure. But finding that ideal location and
> making the perfect static port that does not introduce static air pressure
> errors is not always so quick and easy. And what do we do if we discover
> that the static port that we have installed is not producing accurate
> static
> air pressure? See Note Two below.
>
> ALTITUDE. An altimeter is also a balancing mechanism. It measures the
> difference between the initial altitude setting of the altimeter mechanism
> as compared to the static air pressure encountered by that same mechanism
> while in flight and displays that difference in some lineal measurement
> (usually in feet in our part of the world). If the static pressure provided
> to the altimeter via the static port and the connecting tubing is in error
> or changes with the airplane's airspeed, when the actual altitude is
> constant, then the altimeter's altitude indication will be in error. And
> what do we do if we discover that the static port that we have installed is
> not producing accurate static air pressure? See Note Two below.
>
> 'OC' Says: "The best investment we can make is the effort to gather and
> understand knowledge."
>
> Note One: Why don't we use these long boom and vane type pitot tubes on our
> experimental amateur built aircraft? Because the boom and vane would take a
> terrific beating from people walking into them on the ground and because
> the
> dynamic force errors introduced by the type of pitot tubes that we commonly
> use are just not great enough to cause us concern. There is not very much
> we
> can do about adjusting the force coming from dynamic air pressure other
> than
> using a pitot tube located a sufficient distance from a disturbing piece of
> airframe (usually the bottom surface of a wing) and avoiding a leak or kink
> in the tubing going from the pitot tube to the airspeed indicator.
>
> Note Two: So we have built our airplane, installed our static port(s), and
> discovered that we are getting inaccurate airspeed and / or altitude
> indications and decide to do something about it. We could just go on
> installing new static ports in different locations, but that is a lot of
> work and we are not assured of better results. So we should do just what
> the
> big boy aerodynamic types do, we fudge or bandaid as needed to get the air
> to give us the results that we want.
>
> Let's say that the airspeed indicator is reading too high -- it says the
> airplane is going faster than it really is. (See Note Three). The dynamic
> air pressure side of the airspeed indicator is providing too much force in
> the desired balancing act. How can we counteract that excess dynamic force?
> We increase the static force being fed to the airspeed instrument by the
> static port by installing a small wedge just aft of the opening on the
> static port (thin edge of the wedge facing forward towards the hole). This
> small wedge causes air to pile up and increase the static air pressure
> going
> to the airspeed indicator (and also to the altimeter unless you have
> provided separate static ports for the two instruments) and give us the
> accurate force balance measurement that we want.
>
> Let's say that the altimeter reading goes down 200 feet when you speed up
> 60
> miles per hour (Mike, you did not say which direction your altitude was
> changing with the changes in airspeed). This means that the static port is
> feeding greater than static pressure as your airplane flies faster. How can
> we reduce that undesired increase in static air pressure? We install a
> small
> wedge in front of the hole in the static port (thin edge of the wedge
> facing
> aft towards the hole) to shield it a bit from dynamic air pressure coming
> from the front in order to get a more stable and accurate altitude reading.
>
> How do we get the right size wedge facing the correct direction to get the
> airspeed and altitude results that we want? The same way the big boys do:
> TRIAL AND ERROR and MORE TRIAL AND ERROR. Because our airplanes are
> experimental, amateur built we are permitted to do just that -- experiment.
>
> Note Three: So now we know how to tweak our static port(s) to give us
> accurate airspeed and altitude information, but how do we know that the
> airspeed and altitude information is inaccurate in the first place and
> during our trial and error efforts how do we know when we have achieved the
> accuracy that we are seeking? The answer to those two questions is not as
> simple as one might first expect. I won't attempt to answer them here
> because the answers are too big and complex to answer in this forum. What I
> will suggest is that the reader google "accurate airspeed" and "accurate
> altitude" and delve into those subjects to the level desired. Here is just
> one source you will find:
>
> http://gpsinformation.net/main/altitude.htm
>
> Note Four: This is a personal view point. There are several methods
> available for determining accurate true airspeed. Some rather elaborate --
> some use GPS. Just google "accurate airspeed using GPS".
>
> One thing that I've never quite understood regarding these methods is the
> focus on precisely determining airspeed accuracy indication in the cruising
> airspeed range. If I determine that my airspeed indicator shows 150 knots
> indicated airspeed and I determine through some elaborate scheme that I am
> actually only going 145 knots through the air what do I do with that
> information? Being 5 nautical miles short of my destination after a one
> hour
> flight is a trivial naviagation error contribution compared to all the
> other
> error sources (such as heading, wind, and climb airspeed) that I have to
> contend with and should overcome anyway by some means of real time enroute
> navigation.
>
> I think that if I were going to invest a lot of time and effort in
> determining my exact airspeed error I would be inclined to do that
> determination in the approach airspeed arena, not the cruising airspeed
> arena. And even then I would not be obsessed with absolute airspeed
> accuracy, I'd just want to know what number on the indicator gives me the
> right kind of safe approach and landing time after time.
>
> ================================================
>
> ----- Original Message ----- From: <bwilder@tqci.net>
> To: "Keith Palmer" <kdpalmer@mweb.co.za>
> Cc: "mike mccann" <mvmccann@gmail.com>; "Pulsar builders"
> <pulsar-builders@caseyk.org>
> Sent: Thursday, April 15, 2010 9:18 AM
> Subject: Re: Here's an odd question
>
>
> I noticed that the back half of the round washer where the static exits on
>> the SR22 had the back half of it filed down so there was in effect a
>> little shield protecting the static exit hole. ((Sorry about this
>> description.)
>>
>> I asked the people at their booth why they did that. I think I attended
>> four air shows before I found someone who was involved with the
>> engineering of the system. The answer - - - - "That is what we had to do
>> to make the system work right". There didn't seem to be any theory behind
>> it. They indicated that they had to fiddle around to get it to behave the
>> way they wanted. Maybe they were just trying to get rid of me.
>>
>> In any event, I did the same with mine and it works fine.
>>
>> Bernie Wilder
>>
>
> =============================================
>
>>
>>> ----- Original Message -----
>>> From: mike mccann
>>> To: Pulsar builders
>>> Sent: Thursday, April 15, 2010 5:06 AM
>>> Subject: Here's an odd question
>>>
>>>
>>> All,
>>>
>>> Utilizing a GPS, I've found that my altimeter in my Pulsar varies with
>>> changes in airspeed (altitude will change 100-200 feet with speed
>>> changes of 60 mph).
>>>
>>> Has anyone ever heard of this. Not sure why this would be, or more
>>> importantly, how to fix it.
>>>
>>> Many thanks,
>>>
>>> Mike
>>>
>>> Pulsar 1
>>> N116Km
>>>
>>
>
>
Message 8
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| Subject: | Re: RE: Designing a circuit question |
Just to be clear, if all you want to do is light an LED (the original plan), there's
no need for a relay. Any of those $1 microprocessors should be able to
drive a normal LED directly off an output pin. Of course, if you're going to
the trouble of putting together this sort of circuit, making it control a relay
to take the power off the motor would be a fairly easy add-on.
Doug Ilg
Grumman Tiger N74818, College Park Airport (KCGS), Maryland
Challenger II LSS LW (N641LG reserved) - kit underway at Laurel Suburban (W18)
----- Original Message ----
> From: David <ainut@hiwaay.net>
> To: aeroelectric-list@matronics.com
> Sent: Sun, April 18, 2010 12:41:29 AM
> Subject: Re: AeroElectric-List: RE: Designing a circuit question
>
> Not this one. That would have to be another circuit. A $1 microprossesser
> could handle a $17 relay to do that job.
>
> David
Message 9
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| Subject: | Accurate Altitude and Airspeed |
Sam,
In order for the Dynon to get the correct wind, it must have a accurate
indicated airspeed.
I do not know what you are flying, but the Zenith 601XL with standard pitot
static setup is very inaccurate at cruise speeds.
Check what your indicated vs calibrated speeds are and If possible adjust
to get the indicated very close to calibrated at your cruise speed.
Floyd Wilkes
601XL
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Sam
Hoskins
Sent: Sunday, April 18, 2010 9:43 AM
Subject: Re: AeroElectric-List: Accurate Altitude and Airspeed
This is great information about the static ports. I recently switched from
steam gauges to a Dynon FlightDek. One of the neatest features is the winds
aloft display. Unfortunately, I figured out that it was pretty inaccurate.
One day, I went up and flew four headings and this is what got:
Compass Wind Direction Wind Speed
360 242 20
270 334 18
180 251 31
090 271 08
This told me the display was pretty much worthless. I posted s couple of
notes about it on the Dynon factory forum and was told to look after my
static ports, but no indication how to go about it.
I will definitely be investigating the wedges at the static ports.
Thanks.
Sam Hoskins
Murphysboro, IL
On Thu, Apr 15, 2010 at 5:06 PM, <bakerocb@cox.net> wrote:
4/15/2010
Hello Mike, You wrote: "Not sure why this (altitude variation with airspeed)
would be, or more importantly, how to fix it."
Hello Bernie, You wrote: "There didn't seem to be any theory behind it."
This is not a very rare or mysterious phenomena. Inaccurate airspeed
indications can be caused by inaccurate dynamic and static air pressure
forces. Inaccurate altitude indications can be caused by inaccurate static
pressure forces.
AIRSPEED. Let's talk about inaccurate airspeed measurements first. An
airspeed indicator is a balancing mechanism. It balances the difference
between a force created by dynamic air pressure and a force created by
static air pressure. The force from the dynamic air pressure is the result
of the forward movement of the airplane. The faster the airplane moves the
greater the force exerted.
In order to get an accurate measure of that dynamic force one needs to
accurately sense the free stream dynamic air pressure and send it to the
airspeed indicator via leak and kink free tubing. That means sensing the air
movement in the actual direction that the airplane is moving and having that
air movement not affected by some local air flow direction change caused by
the airframe itself. This is why you sometimes see flight test airplanes
with a long boom sticking out forward with a small vane mechanism on the
front of it. This boom and vane mechanism, along with connecting tubing, is
a pitot tube system intended to accurately measure the force from the free
stream dynamic air pressure without any inaccuracies introduced by local
airframe air flow. See Note One below.
So much for the dynamic force side of the airspeed indicator balancing act,
what about the static force side? An accurate static force is provided by a
static port ideally located somewhere on the airframe such that it is
measuring the true static air pressure. But finding that ideal location and
making the perfect static port that does not introduce static air pressure
errors is not always so quick and easy. And what do we do if we discover
that the static port that we have installed is not producing accurate static
air pressure? See Note Two below.
ALTITUDE. An altimeter is also a balancing mechanism. It measures the
difference between the initial altitude setting of the altimeter mechanism
as compared to the static air pressure encountered by that same mechanism
while in flight and displays that difference in some lineal measurement
(usually in feet in our part of the world). If the static pressure provided
to the altimeter via the static port and the connecting tubing is in error
or changes with the airplane's airspeed, when the actual altitude is
constant, then the altimeter's altitude indication will be in error. And
what do we do if we discover that the static port that we have installed is
not producing accurate static air pressure? See Note Two below.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
Note One: Why don't we use these long boom and vane type pitot tubes on our
experimental amateur built aircraft? Because the boom and vane would take a
terrific beating from people walking into them on the ground and because the
dynamic force errors introduced by the type of pitot tubes that we commonly
use are just not great enough to cause us concern. There is not very much we
can do about adjusting the force coming from dynamic air pressure other than
using a pitot tube located a sufficient distance from a disturbing piece of
airframe (usually the bottom surface of a wing) and avoiding a leak or kink
in the tubing going from the pitot tube to the airspeed indicator.
Note Two: So we have built our airplane, installed our static port(s), and
discovered that we are getting inaccurate airspeed and / or altitude
indications and decide to do something about it. We could just go on
installing new static ports in different locations, but that is a lot of
work and we are not assured of better results. So we should do just what the
big boy aerodynamic types do, we fudge or bandaid as needed to get the air
to give us the results that we want.
Let's say that the airspeed indicator is reading too high -- it says the
airplane is going faster than it really is. (See Note Three). The dynamic
air pressure side of the airspeed indicator is providing too much force in
the desired balancing act. How can we counteract that excess dynamic force?
We increase the static force being fed to the airspeed instrument by the
static port by installing a small wedge just aft of the opening on the
static port (thin edge of the wedge facing forward towards the hole). This
small wedge causes air to pile up and increase the static air pressure going
to the airspeed indicator (and also to the altimeter unless you have
provided separate static ports for the two instruments) and give us the
accurate force balance measurement that we want.
Let's say that the altimeter reading goes down 200 feet when you speed up 60
miles per hour (Mike, you did not say which direction your altitude was
changing with the changes in airspeed). This means that the static port is
feeding greater than static pressure as your airplane flies faster. How can
we reduce that undesired increase in static air pressure? We install a small
wedge in front of the hole in the static port (thin edge of the wedge facing
aft towards the hole) to shield it a bit from dynamic air pressure coming
from the front in order to get a more stable and accurate altitude reading.
How do we get the right size wedge facing the correct direction to get the
airspeed and altitude results that we want? The same way the big boys do:
TRIAL AND ERROR and MORE TRIAL AND ERROR. Because our airplanes are
experimental, amateur built we are permitted to do just that -- experiment.
Note Three: So now we know how to tweak our static port(s) to give us
accurate airspeed and altitude information, but how do we know that the
airspeed and altitude information is inaccurate in the first place and
during our trial and error efforts how do we know when we have achieved the
accuracy that we are seeking? The answer to those two questions is not as
simple as one might first expect. I won't attempt to answer them here
because the answers are too big and complex to answer in this forum. What I
will suggest is that the reader google "accurate airspeed" and "accurate
altitude" and delve into those subjects to the level desired. Here is just
one source you will find:
http://gpsinformation.net/main/altitude.htm
Note Four: This is a personal view point. There are several methods
available for determining accurate true airspeed. Some rather elaborate --
some use GPS. Just google "accurate airspeed using GPS".
One thing that I've never quite understood regarding these methods is the
focus on precisely determining airspeed accuracy indication in the cruising
airspeed range. If I determine that my airspeed indicator shows 150 knots
indicated airspeed and I determine through some elaborate scheme that I am
actually only going 145 knots through the air what do I do with that
information? Being 5 nautical miles short of my destination after a one hour
flight is a trivial naviagation error contribution compared to all the other
error sources (such as heading, wind, and climb airspeed) that I have to
contend with and should overcome anyway by some means of real time enroute
navigation.
I think that if I were going to invest a lot of time and effort in
determining my exact airspeed error I would be inclined to do that
determination in the approach airspeed arena, not the cruising airspeed
arena. And even then I would not be obsessed with absolute airspeed
accuracy, I'd just want to know what number on the indicator gives me the
right kind of safe approach and landing time after time.
=======================
----- Original Message ----- From: <bwilder@tqci.net>
Cc: "mike mccann" <mvmccann@gmail.com>; "Pulsar builders"
<pulsar-builders@caseyk.org>
Sent: Thursday, April 15, 2010 9:18 AM
Subject: Re: Here's an odd question
I noticed that the back half of the round washer where the static exits on
the SR22 had the back half of it filed down so there was in effect a
little shield protecting the static exit hole. ((Sorry about this
description.)
I asked the people at their booth why they did that. I think I attended
four air shows before I found someone who was involved with the
engineering of the system. The answer - - - - "That is what we had to do
to make the system work right". There didn't seem to be any theory behind
it. They indicated that they had to fiddle around to get it to behave the
way they wanted. Maybe they were just trying to get rid of me.
In any event, I did the same with mine and it works fine.
Bernie Wilder
====================
----- Original Message -----
From: mike mccann
To: Pulsar builders
Sent: Thursday, April 15, 2010 5:06 AM
Subject: Here's an odd question
All,
Utilizing a GPS, I've found that my altimeter in my Pulsar varies with
changes in airspeed (altitude will change 100-200 feet with speed
changes of 60 mph).
Has anyone ever heard of this. Not sure why this would be, or more
importantly, how to fix it.
Many thanks,
Mike
Pulsar 1
N116Km
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Message 10
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| Subject: | Re: Accurate Altitude and Airspeed |
On 2010-04-15, at 18:06 , <bakerocb@cox.net> <bakerocb@cox.net> wrote:
> One thing that I've never quite understood regarding these methods is the
> focus on precisely determining airspeed accuracy indication in the cruising
> airspeed range. If I determine that my airspeed indicator shows 150 knots
> indicated airspeed and I determine through some elaborate scheme that I am
> actually only going 145 knots through the air what do I do with that
> information? Being 5 nautical miles short of my destination after a one hour
> flight is a trivial naviagation error contribution compared to all the other
> error sources (such as heading, wind, and climb airspeed) that I have to
> contend with and should overcome anyway by some means of real time enroute
> navigation.
>
> I think that if I were going to invest a lot of time and effort in
> determining my exact airspeed error I would be inclined to do that
> determination in the approach airspeed arena, not the cruising airspeed
> arena. And even then I would not be obsessed with absolute airspeed
> accuracy, I'd just want to know what number on the indicator gives me the
> right kind of safe approach and landing time after time.
As you note, an accurate airspeed indication is not really that important, looked
at in isolation. Even if there is a significant error at approach speeds,
it is not so important as long as the error is the same on every flight. Determining
what IAS our aircraft needs for a safe, effective approach and landing
is one of the many things we will do during the flight test phase.
But, with modern avionics, many EFIS systems calculate TAS based on IAS, altitude
and temperature, and use that in conjunction with GPS track and groundspeed
to calculate wind. They then put a nice little wind vector on the display, and
it bugs the heck out of folks if the wind info is wrong.
The most important aspect of static system errors is not the effect on IAS. The
important aspect is the effect on the altimeter accuracy. It is quite possible
to have static system position errors that will give over 100 ft error in
the altimeter at cruise airspeeds. If we are flying at our VFR cruising altitude,
and there is IFR traffic that is supposed to be 500 ft above or below us,
errors in our static system can become significant. If we have 100 ft of static
system error, plus each aircraft has 50 ft of altimeter instrument error,
plus perhaps we are not on quite the right altimeter setting because we aren't
using flight following, and each pilot is 50 ft high or low from his nominal
indicated altitude, these errors may add up. It is quite conceivable that aircraft
that are supposed to be 500 ft apart may turn out to be a have less than
200 ft of altitude separation. If we are flying IFR approaches in IMC, the
effect of static system position error on our altimeter is important to know.
--
Kevin Horton
RV-8
Ottawa, Canada
http://www.kilohotel.com/rv8
Message 11
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| Subject: | Re: Crowbar OV module part |
Phil: I sent you an off-list response on your MBS 4991 problem using
your aol address on 4/11. If you did not receive it and would like to,
let me know off list at mcculleyja@starpower.net.
JIM
=========================================================================
Phil wrote:
>
> Bob: The part listed as "MBS4991" is no longer carried by Digi-Key.
> Mouser lists a possible replacement as a silicon bi-lateral switch by
> NTE as their part NTE6403. Is this the correct type item? Or is that
> device something else?
>
> Need to build 2 OV modules for my electrically dependent, dual
> alternator project.
>
> Phil
> RV-10 w/ Mazda 20B rotary engine in IL
============================================================================
Message 12
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On 4/18/2010 8:52 AM, jtortho@aol.com wrote:
>
> I realize this is more avionics then electrics, but this place is my
> primary resource.
>
> After a small building hiatus, I am back on wiring my panel.
>
> the 300 xl has MIC Audio hi and Low as possible inputs.
>
> The AVCOM AC6PA intercom has a MIC to Radio output, but I cannot find:
>
> output levels at that MIC to radio connector in the AVCOM book.
>
> input levels listed in the 300XL installation for either input.
>
>
> Anybody have the answer or an additional resource to review?
>
> Jim Timoney
> Searey 80% done, 90% to go
Hi Jim,
Typically, the 'hi' & 'low' in aviation radio/intercom terminology
refers to signal (hi) and return path (low), rather than different
levels. I'd expect the intercom's mic to radio terminal to go to the mic
hi terminal on the radio. I'd expect the mic low terminal to connect to
the intercom's 'low' or 'ground' or 'return', etc; depending on AVCOM's
terminology.
Hope that helps.
Charlie
Message 13
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| Subject: | Re: Zeftronics G1200N |
Good Afternoon Peter,
To tell you the truth, I don't remember. I kinda think they were mentioned
,
but have no recollection of the manner.
Happy Skies,
Old Forgetful Bob
In a message dated 4/18/2010 9:27:17 A.M. Central Daylight Time,
vk3eka@bigpond.net.au writes:
Bob,
Thanks, did you ever get a copy of the fault light codes?
Looks like I=99ll have to do a little more testing.
Cheers
Peter
Message 14
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| Subject: | Re: Designing a circuit question |
At 06:01 PM 4/17/2010, you wrote:
>I have an in flight adjustable IVO prop. What
>Id like to have is a light that indicates when
>I get to the flat pitch stop without adding rings and brushes.
>For those who arent familiar with the IVO, the
>adjustment is made by a motor driving a
>jack-screw that moves a collar which torques a
>rod embedded in the blades. There are no
>electrical stops, just a rubber washer at each
>end of the run. When the collar hits the end,
>the motor stalls. The rubber washer provides a
>softer stall which is a bit easier on the gears
>driving the jack screw. A 10A CB is the
>ultimate stop. Not elegant, but it works.
>On the ground, before starting the engine, its
>easy to verify the prop is in fine pitch by
>listening to the motor. The problem is before
>landing, when Id like to have the prop in fine
>pitch, it has to be done by guess and feel, or
>just hold the switch until the CB pops which
>is not a good thing to do on a regular basis.
>So, what Id like is a circuit that can sense an
>amperage spike going over 9A would be perfect
> and turn on a light (LED of course :-) The
>ramp up to 9A is steep goes from 5-6A to 9A very quickly (if that helps).
>I can build the circuit, I just dont know how to design it.
The reed switch sensor Joe mentioned is worthy of further
thought. You could also build a simple constant current
generator set for something less than the CB trip current.
By watching for the voltage to spike across the generator
could light an LED to indicate end-of-travel and stop using
the CB as an operating indicator.
I'm just getting ready to head for Wichita but I'll noodle
the idea on the way up. I can perhaps publish something later
this evening.
Bob . . .
Message 15
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| Subject: | how to wire an electret microphone |
I am considering trying to build a headphone for my plane. Can someone tell
me how to wire an electret microphone like the one below so that it can be
plugged into the planes jack?
http://www.radioshack.com/product/index.jsp?productId 62216
You can safely assume that I am dumb enough to try this with absolutely no
knowledge of how to do it and would need a very good explanation.
Something like, "just use a condenser.", will not help me much. :>)
Bill B
Message 16
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| Subject: | Re: RE: Designing a circuit question |
Doug,
It may be clear to you, but you've got to do better than that to be clear to
me :-)
I understand the concept, but need a circuit diagram, and which $1
microprocessor to use.
I agree that once I know how to turn the LED on, adding a relay is straight
forward. Have to admit I hadn't thought of that. I have to think about it
and decide if it is worth the extra complexity and parts - vs. just me just
letting go of the switch...
Dennis
----------------------
Just to be clear, if all you want to do is light an LED (the original plan),
there's
no need for a relay. Any of those $1 microprocessors should be able to
drive a normal LED directly off an output pin. Of course, if you're going
to
the trouble of putting together this sort of circuit, making it control a
relay
to take the power off the motor would be a fairly easy add-on.
Doug Ilg
Message 17
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| Subject: | Re: RE: Designing a circuit question |
Dennis,
I'm not really the right person to give lessons on microprocessors. All that I've
done is to implement simple schematics and programs that I found on the 'net.
(A quick search for "PIC16" should find some sites with projects for that
popular line of microprocessors.) I know from that that you can drive an LED
directly off an output pin with an appropriate resistor.
My point was to tell you that the relay that was referred to is not necessary for
your original purpose (to light an LED). It would be useful to actually interrupt
current to the motor, if you chose to do that.
Maybe the person who originally suggested using a microprocessor can give you better
advice on how to use those.
Doug Ilg
Grumman Tiger N74818, College Park Airport (KCGS), Maryland
Challenger II LSS LW (N641LG reserved) - kit underway at Laurel Suburban (W18)
----- Original Message ----
> From: Dennis & Anne Glaeser <glaesers@wideopenwest.com>
> To: aeroelectric-list@matronics.com
> Sent: Sun, April 18, 2010 6:42:02 PM
> Subject: AeroElectric-List: Re: RE: Designing a circuit question
Doug,
It
> may be clear to you, but you've got to do better than that to be clear to
me
> :-)
I understand the concept, but need a circuit diagram, and which
> $1
microprocessor to use.
I agree that once I know how to turn the LED on,
> adding a relay is straight
forward. Have to admit I hadn't thought of
> that. I have to think about it
and decide if it is worth the extra
> complexity and parts - vs. just me just
letting go of the
> switch...
Message 18
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| Subject: | Re: how to wire an electret microphone |
Bill,
With good headphones so cheap, especially 2nd hand, I don't know why you
would want to do this. Especially since all the deep pocket guys have
tossed over their faithful ANR headsets for the Bose and Zulu models.
However,... the first thing is to probably consider is the type of mike
element. It has to deal with cancelling most of the back ground noise.
I am guessing the RS mike element may not qualify as a noise cancelling
mike....
David
-------------------------------------------------------------------------
-------
----- Original Message -----
From: Bill Bradburry
To: aeroelectric-list@matronics.com
Sent: Sunday, April 18, 2010 12:59 PM
Subject: AeroElectric-List: how to wire an electret microphone
I am considering trying to build a headphone for my plane. Can
someone tell me how to wire an electret microphone like the one below so
that it can be plugged into the planes jack?
http://www.radioshack.com/product/index.jsp?productId 62216
You can safely assume that I am dumb enough to try this with
absolutely no knowledge of how to do it and would need a very good
explanation.
Something like, "just use a condenser.", will not help me much. :>)
Bill B
Message 19
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| Subject: | Re: how to wire an electret microphone |
Bill=3B
Trying to build headphones for the exercise of doing could certainly be par
t of the learning experience if you have the time available=2C however=2C y
ou might want to check the product reviews found on the link you provided.
The description says this is an "Electret Mic" but one of the reviews point
s out that in fact it is actually a "Condenser Mic". I don't know the signi
ficance of that discrepancy=2C but it is something you might want to note.
Bob McC
Bill=2C
With good headphones so cheap=2C especially 2nd hand=2C I don't know why yo
u would want to do this. Especially since all the deep pocket guys have to
ssed over their faithful ANR headsets for the Bose and Zulu models.
However=2C... the first thing is to probably consider is the type of mike e
lement. It has to deal with cancelling most of the back ground noise. I a
m guessing the RS mike element may not qualify as a noise cancelling mike..
..
David
----- Original Message -----
From: Bill Bradburry
Sent: Sunday=2C April 18=2C 2010 12:59 PM
Subject: AeroElectric-List: how to wire an electret microphone
I am considering trying to build a headphone for my plane. Can someone tel
l me how to wire an electret microphone like the one below so that it can b
e plugged into the planes jack?
http://www.radioshack.com/product/index.jsp?productId 62216
You can safely assume that I am dumb enough to try this with absolutely no
knowledge of how to do it and would need a very good explanation.
Something like=2C =93just use a condenser.=94=2C will not help me much=85
:>)
Bill B
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.ma
tronics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
Message 20
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| Subject: | B & C Specialties Warning Light- Would Like to Dim |
I'm starting a significant upgrade of the VFR-only panel in my flying GlaStar to
an IFR panel. I currently have the B & C Specialty LR3C-14 alternator controller
and will be installing the B & C SD-20 standby alternator with a SB1B-14
controller. The currently installed low voltage light will be replaced with
a "standby alternator on" light.
The current warning light is way too bright, especially at night. I expect the
standby alternator "on" light to be just as bright.
Is there an easy way to dim the light after it has come on and gotten my attention?
If dimming it is too difficult, I'm thinking of adding a small switch so
I can shut it off after it has come on. This switch would be normally "on" and
I'd have to add that as a checklist item.
I already have and will continue to use a B & C dimmer (DIM5-14 or DIM15-14).
If I recall correctly, it will handle two or three different circuits. Can it
be wired such that it will dim the warning light while increasing the brightness
of the other circuit -- say my other panel lights -- or do all circuits have
to work in the same direction? If it can dim one circuit while brightening
up the other, I think I could find a happy medium and use existing hardware.
Bob
GlaStar
N248BF
~300 Hours
Message 21
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| Subject: | Re: how to wire an electret microphone |
At 19:34 4/18/2010, you wrote:
>The description says this is an "Electret Mic" but one of the
>reviews points out that in fact it is actually a "Condenser Mic". I
>don't know the significance of that discrepancy, but it is something
>you might want to note.
An electret mic is nothing more than internally polarized condenser
mic that only needs an external low voltage applied to make the
innards (amplifier) work. Most inexpensive ones are
omni-directional, and any response pattern is achieved in how it is
mounted and packaged.
Ron Q.
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