Today's Message Index:
----------------------
1. 01:13 AM - Grounding of head phone jacks (f1rocket@telus.net)
2. 01:26 AM - Dual antennae (f1rocket@telus.net)
3. 04:06 AM - Re: Pitch Trim Motor Slowdown (KITFOXZ@aol.com)
4. 07:23 AM - Re: Grounding of head phone jacks (Don Boardman)
5. 07:45 AM - Re: Reusing batteries (Robert L. Nuckolls, III)
6. 07:50 AM - Re: To E-Buss or not To E-buss (Robert L. Nuckolls, III)
7. 08:51 AM - Re: To E-Buss or not To E-buss (Don Boardman)
8. 10:38 AM - cooling fans, ONE DOLLAR (Dan Checkoway)
9. 12:42 PM - Myths and urban ledgends about motors (Robert L. Nuckolls, III)
10. 12:51 PM - To E-Buss or not To E-buss (Scott Diffenbaugh)
11. 03:19 PM - B&C 40 amp alternator : "F" tab? (Rick Fogerson)
12. 03:59 PM - Pitot Tube Wire (Brett Ferrell)
13. 04:50 PM - Re: Myths and urban ledgends about motors (Benford2@aol.com)
14. 05:18 PM - Re: Pitot Tube Wire (Richard@riley.net)
15. 06:13 PM - Re: Pitot Tube Wire (Phil Collins)
16. 08:40 PM - Re: B&C 40 amp alternator : "F" tab? (Dan Checkoway)
17. 10:40 PM - Re: NiMH batteries (j1j2h3@juno.com)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Grounding of head phone jacks |
--> AeroElectric-List message posted by: f1rocket@telus.net
Bob,
In one of the earlier postings you mentioned grounding of the head phone jacks
(female) back through the shield and only ground at the intercom/radio end.
I'm building an all metal plane, and will be following this advice, but when I
attach the head phone jack, I was just planning on drilling through a piece of
metal that is of course attached to the airframe.
My question is: Do the head phone jacks have an insolator built in (protecting
it from grounding at this location), or do I need to take some special care.
OR am I worrying about nothing (grounding at both ends acceptable).
I got down to reading your book, and I must say I'm impressed. Anyone on this
site should buy it, well worth the money. I esspecially like the fact that the
solutions are practical and you make it very easy to understand.
Jeff
F1 in progress
>
>
>
>
>
>
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: f1rocket@telus.net
Hi Bob,
In your book you mention about using dual antennae on the comm side.
What I'm thinking is to build two of the nav antennae you describe in the book,
and put a splitter (any idea where I can get one) in. Yes I know that the nav
is horizontal, and the comm is vertical, but my thinking was that two in the
wingtips should beat one underneath. Or am I out to lunch here? On the
splitter side, I know from commercial radio use, we try and keep the distance
between the base station (or amp) and the actual antenna as short as practical,
and I wonder if I will be loosing too much signal trying to split between two.
Maybe the one on the bottom is the best idea? The distance to each wing tip
antenna will be around 11 feet then to the radio stack will be about.
While I'm on the subject of antennae, does anyone know of a hidden ADF antennae
system?
On both the above subjects, the plane is all metal, so I have only a few places
to hide antennae and still end up with some sort of ground plane (still waiting
for someone to have the idea of hiding one in the gear leg fairings - if the
ground plane is sufficient).
Jeff
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Pitch Trim Motor Slowdown |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
In a message dated 12/5/2003 11:35:24 PM Eastern Standard Time,
joberst@cox-internet.com writes:
I previously posted a question on how to cut down the speed of my 12V DC
pitch trim motor. I got one response, which suggested I use the the
Matronics Mark III adjustable speed governor. I have two issues with
this... first, it is unclear to me what the current capacity of this unit is
(does anyone know that? - I am not using MAC servos)... second, it looks
like a bit of overkill, as I don't want adjustable speed, ground-actuation,
multiple switches - just a permanent slowdown to one speed.
Can anyone explain to me what the design goal is for a DC motor slowdown
circuit? I've been told that a simple dropping resistor could cause the
motor to overheat. Also, I don't want to do something to reduce the torque.
Will a fixed voltage regulator do it, or does it need to be pulsed, or??
Thanks.
Jim Oberst
Hello Jim,
The Matronics unit is probably the slickest way to do the job because you
will still have full tork available at slow speeds. Using a simple dropping
resistor will allow it to run at some lower voltage and slower speed, but also
with lower tork. A DC motor will not overheat this way. A/C motors overheat at
lower than designed voltages because the lower voltage does not allow their
A/C armature to turn up to designed RPM and they lag out of phase with their A/C
field. The heater/air conditioner DC motored blower in your car uses a
simple voltage divider resistor bank to give you 3 or more speeds typically. This
voltage divider is just two or more high wattage resistors wired in series
with the motor switch. The switch picks off one or more resistors to add to the
circuit. I might add that the resistors are in the supply air stream for
cooling.
With the right resistor and heat sink (you could strap the hot little devil
to the motor itself) you just may have the perfect solution for little money.
You will have to experiment (that's what we do right?) to see if say, half
speed (and half tork) will do the job.
How about a couple of push buttons (up/down) in parallel with your normal
pitch trim rocker switch that are wired to a one shot timed relay? A push of
either of the buttons will give you a pre set pulse to the motor at full voltage
but for only a few milliseconds. Repeating the push of the button will
reactivate the timed relay cycle. Here, you will have full tork but for a very
fine
adjustment.
You might toy with using a center tapped ship's battery thus making 6 volts
easily available to the pitch trim motor.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Grounding of head phone jacks |
--> AeroElectric-List message posted by: Don Boardman <dboardm3@twcny.rr.com>
Hi Jeff,
I can help you with this one. Bob's friends at B&C Specialty Products:
http://www.bandc.biz/parts.html
Sells the perfect Headset/Mic Jack Insulating Washer. The direct link is
below.
http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?24X358218#s892
Regards,
Don Boardman
& Partner, Randy Bowers
Super Moose #130 M-14PF 400HP, MT-prop/beta, Aerocet 3500 amphibs, Rome, NY
> Bob,
>
> In one of the earlier postings you mentioned grounding of the head phone jacks
> (female) back through the shield and only ground at the intercom/radio end.
> I'm building an all metal plane, and will be following this advice, but when
I
> attach the head phone jack, I was just planning on drilling through a piece of
> metal that is of course attached to the airframe.
> My question is: Do the head phone jacks have an insolator built in
> (protecting
> it from grounding at this location), or do I need to take some special care.
> OR am I worrying about nothing (grounding at both ends acceptable).
>
> I got down to reading your book, and I must say I'm impressed. Anyone on this
> site should buy it, well worth the money. I esspecially like the fact that
> the
> solutions are practical and you make it very easy to understand.
>
> Jeff
> F1 in progress
>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Reusing batteries |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:31 PM 12/5/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
>
>" The most life any one battery would see would be three years (one in the
>plane and two in the car)."
>
>I don't think so.
It's helpful to explain your deduction. If the airplane has
one battery changed out every year with used battery rotate to
car, then next year, one would be rotating a two year battery
out of the car in exchange for a one-year battery out of the
airplane. If the airplane has two batteries then a one year
battery rotates from main battery to aux battery and two year
old aux battery goes to car. At next annual, a three year old
battery in car gets replaced with another two year old battery
from the airplane. I'll suggest that in later scenario, total
battery service would be three years with two of those years
in the airplane.
Bob . . .
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: To E-Buss or not To E-buss |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 01:27 AM 12/6/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: Don Boardman <dboardm3@twcny.rr.com>
>
>Hi Bob and list,
>
>We are installing the All Electric Airplane on a Budget using Z-13.
>We have a 50 amp main alt. and the SD-8 on the vac. pad.
>
>My thoughts are about the elimination of the E-buss.
>If we loose the main alternator we would bring the SD-8 on line and simply
>turn off non-essential items bringing the total load on the system to 8 amps
>or less.
But what if you loose the battery contactor?
>In reviewing the loads on the system we come up with only a few that are not
>controlled by a switch. Clock and CD player keep alive and engine
>instruments. Clock and CD use less than a mA and will be on the always hot
>buss. That leaves the engine instruments as the only other loads not
>controlled by a switch. Instrument loads total .94 amps and if we add the
>battery contactor at 1 amp this results in a 2 amp load that we would not
>have control over. Leaving the question, is 6 amps enough to run the items
>we will need for a safe completion of the flight. If the answer is yes, then
>why not simply leave the load reduction to the pilot who would switch off
>the non essential items and illiminate the E-buss. This gives the pilot the
>option of turning on an item that might have been relligated to the main
>buss but could be useful for a short period of time and then turned off
>again.
>
>It looks like the items we would place on our E-buss run between 5-6 amps.
>So the loss of the 2 amps (instruments and contactor) buy simply staying
>with the main bus and turning off items to reduce load would seem to make
>sense.
>
>So in the event we lost the main alt. ...we would... move the Master to Bat,
>move the Aux Alt to on, turn off all unnecissary loads. At the airport,
>battery still up, put the gear down and land.
>
>Am I missing something?
Yup. The e-bus alternate feed path has two purposes. (1) Second path
to most reliable power source in event battery contactor is lost
and (2) means by which battery only operations loads may be reduced
to minimum en route values for endurance. The fact that you've added
and SD-8 only means that e-bus loads can now be as great as 8-10 amps
so that the battery can be held in reserve for approach to landing
by turning the battery master back on. If the battery master has
failed, difference in outcome of flight is insignificant.
Bob . . .
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: To E-Buss or not To E-buss |
--> AeroElectric-List message posted by: Don Boardman <dboardm3@twcny.rr.com>
Hi Bob,
Hope your Saturday is going well.
>> My thoughts are about the elimination of the E-buss.
>> If we loose the main alternator we would bring the SD-8 on line and simply
>> turn off non-essential items bringing the total load on the system to 8 amps
>> or less.
>
> But what if you loose the battery contactor?
> Yup. The e-bus alternate feed path has two purposes. (1) Second path
> to most reliable power source in event battery contactor is lost
Good point.
Bob, is it possible to keep the alternate feed switch, eliminate the E-bus
connecting the feed to the main bus? If possible would you need to use the
diode turned to feed the main bus or eliminate the diode all together?
>(2) means by which battery only operations loads may be reduced
> to minimum en route values for endurance. The fact that you've added
> and SD-8 only means that e-bus loads can now be as great as 8-10 amps
> so that the battery can be held in reserve for approach to landing
> by turning the battery master back on. If the battery master has
> failed, difference in outcome of flight is insignificant.
If it is possible to feed the main bus using the alternate feed and loads
are controlled by turning off items so that the battery is still up on
arrival then the loss of the contactor would be a non issue as the items on
the main bus would still be available at the airport.
Help,
Don B.
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | cooling fans, ONE DOLLAR |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
There's been some talk about cooling fans, and people have mentioned 8-12
bucks (I think). No need to spend that much:
$1 each: http://store.yahoo.com/nexfan03/evcafan80bl.html
Or, for quieter, ball bearing, $4.99 each:
http://store.yahoo.com/directron/uc001btc.html
http://store.yahoo.com/directron/80l1a.html
)_( Dan
RV-7 N714D
http://www.rvproject.com
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Myths and urban ledgends about motors |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
<snip>
>The Matronics unit is probably the slickest way to do the job because you
>will still have full tork available at slow speeds. Using a simple dropping
>resistor will allow it to run at some lower voltage and slower speed, but
>also
>with lower torque. A DC motor will not overheat this way. A/C motors
>overheat at
>lower than designed voltages because the lower voltage does not allow their
>A/C armature to turn up to designed RPM and they lag out of phase with
>their A/C
>field. The heater/air conditioner DC motored blower in your car uses a
>simple voltage divider resistor bank to give you 3 or more speeds
>typically. This
>voltage divider is just two or more high wattage resistors wired in series
>with the motor switch. The switch picks off one or more resistors to add
>to the
>circuit. I might add that the resistors are in the supply air stream for
>cooling.
<snip>
Lets separate apples and oranges here. There's no direct relationship
between operation/performance of AC squirrel-cage motors and brush
type dc motors. They're totally different technologies bounded by
different limits.
A series resistor will allow adjustment of PM motor speed
from zero to full speed as will application of a variable
voltage from 0 to rated volts.
A permanent magnet motor output torque is proportional
to current. One raises current draw by increasing LOAD on the
motor. Motor current is defined thusly:
Amps = (Eapplied-CounterEMF)/Ohms
Counter EMF (the voltage the PM motor would GENERATE if
spun up by an external rotation. Counter EMF is directly
proportional to speed. - You can use a PM motor
as a wind speed indicator. Mount one on roof with anemometer
cups to spin it, put a voltmeter on lead wires and calibrate
voltmeter in MPH wind speed.
Put a voltage on a motor and it runs. If nothing is attached
to the shaft, torque on the motor is limited to bearing and
brush friction plus internal windage (yes, aerodynamic drag
on rapidly rotating motor parts is a significant loss to be
considered during design).
Take a peek at this hypothetical motor:
http://www.aeroelectric.com/articles/Motors/PM_Motor_Constants.gif
Lets suppose we hook a 12 battery to this motor. What might
we expect? With Kb of 2v/1000 rpm, we can expect this motor
to run at slightly under 6000 rpm. If it had zero losses
(meaning also zero torque) then it would run at a speed
that produces a counter voltage exactly equal to applied voltage.
Torque is described like so:
Torque Constant (Kt) = Torque (oz-in)
Now, let's load this motor with a 2 in-oz load. With
a Kt of 1 in-oz per amp, we can expect the load current on
this motor to go up to 2 amps. With an internal resistance
of 1 ohm, we'll see a 2 volt drop. This means that Counter
EMF (generated volts) has to drop to 10 volts. At 2v/1000 rpm, the
NEW speed for this motor is 5000 rpm.
Hmmm . . . . okay, lets suppose we wanted to run this motor
with the same load but needed to slow it down to 3000 rpm.
What's a mother to do? We COULD add a resistor in series.
How big a resistor? With a new counter EMF of 6 volts,
we need to toss off 6 volts in total system resistance. With
a load of 2A, this means total resistance needs to be
3 ohms. 1 ohm is built into the motor so adding a 2 ohm
resistor should do the trick . . . and it will.
Now lets say that by the time our mechanism
is at limit, its load has increased to
3 in-oz. Okay, now the motor will be drawing 3 amps
instead of 2. What happens to speed? 3 amps of load
through our 3 ohms total resistance tosses off 9 volts.
Counter EMF drops to 3 volts which means that motor speed
at end of mechanism travel will drop to 1500 rpm.
Okay, we can say that speed regulation for this system
over stroke limits of the mechanism is 1500 to 3000 rpm . . .
a 1:2 ratio. If this is satisfactory to you. then perhaps
a series resistor will fill the bill.
Plan B says that we drive the motor with a constant
VOLTAGE source not unlike out dimmer regulators or several
other approaches. Now, what do we need to do to slow the
motor to 3,000 RPM operating speed? We still have the
predicted 2A load at beginning of stroke with 2 volt
being tossed off by internal resistance of the motor.
So, to get 3,000 RPM we need 6V Counter EMF added to
2 volts resistive loss for a total of 8 volts from our
constant voltage controller.
Now, as we reach end of stroke and current rises to
3A, the 1 ohm internal resistance of the motor will
toss off 3 volts of applied leaving us with a Counter
EMF requirement of 5 volts. 5 V divided by Kb of
2V/kRpm yields a new speed of 2500 rpm. Net change
of speed over stroke for constant voltage is 500
rpm or about 15%. Net change of speed over stroke
for series resistance is 1500 rpm or 50%.
In relatively constant load situations like blowers,
a series resistance is often adequate to the task.
In trim system operations where part of the trim
mechanism is a nut running on a threaded shaft,
actuator efficiency is so low that most of the
electrical energy fed to the actuator is used to
move the actuator . . . variable LOAD on actuator
have smaller effects on CURRENT and therefore smaller
effects on SPEED.
(Actuator in Beechject draws 2.5A unloaded, 2.9
amps under 350 pounds of aerodynamic loads . . .
motor speed doesn't change much under variable
loads in flight).
Consider too that voltage applied to the motor
is a function of both the control technology
-AND- system voltage. We generally design speed
control for trim systems to operate over DO-160
range of inputs . . . in a 14V airplane this
means 10.5 to 15.0 volts. In this case, a series
resistor is clearly not going to cut it.
In fact, we generally don't even use constant
voltage control. A speed sensor on the motor
is used to detect and correct applied voltage
so that speed is indeed constant. I put the first
trim speed controllers on Lears about 1980.
Trim speeds varied less than 1% from set-point
for all effects of voltage, load, temperature
and altitude combined.
In summary . . . motor CURRENT is function of
LOAD. The act of restricting available input
energy via reduction of voltage or inclusion
of resistance does not cause load to go up therefore
current doesn't go up either and motor is NOT
in danger of self-destruction by immolation.
Be assured also that you're not putting a
motors at risk by experimentation
with any speed control methodology. The perceived
drop off in performance observed with series
resistance control in no way alters the motor's
torque characteristics . . . in cases cited
above, operating torque was consistent at 2 to
3 in-oz. The extra-ordinary SPEED change
for series resistance control was a function
of loss of STABILITY of VOLTAGE applied to
terminals of the motor.
The methodology you choose to adjust speed of
any motor MUST account for variability of both
loads and system voltage. When in doubt about
load variation, a constant voltage controller
is easy to implement and will yield performance
that is more predictable.
In any case, what ever method you choose for
first flight can easily be changed if found
lacking in performance . . . not so for the
holy-watered birds.
Bob . . .
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | To E-Buss or not To E-buss |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
Hi Don,
There is a lot of good stuff in the archives on this subject. Go to:
www.matronics.com/searching/search.html. Select the aeroelectric list and
search the subject.
It appears pretty tough to improve on the Z-13 -- I have taken several
cracks at it in the process of becoming educated in all of the ins and outs.
I thought I was on to something only to have Bob point out the FAA frowns on
my idea.
Regarding your proposal, the E-bus provides for a separate source of power
to essential devices to get you down. Without it, if you were to lose your
battery contactor, you would be SOL.
Regards, RV7A
Scott Diffenbaugh
diff@foothill.net
Time: 10:25:59 PM PST US
Subject: AeroElectric-List: To E-Buss or not To E-buss
From: Don Boardman <dboardm3@twcny.rr.com>
--> AeroElectric-List message posted by: Don Boardman
<dboardm3@twcny.rr.com>
Hi Bob and list,
We are installing the All Electric Airplane on a Budget using Z-13.
We have a 50 amp main alt. and the SD-8 on the vac. pad.
My thoughts are about the elimination of the E-buss.
If we loose the main alternator we would bring the SD-8 on line and simply
turn off non-essential items bringing the total load on the system to 8 amps
or less.
In reviewing the loads on the system we come up with only a few that are not
controlled by a switch. Clock and CD player keep alive and engine
instruments. Clock and CD use less than a mA and will be on the always hot
buss. That leaves the engine instruments as the only other loads not
controlled by a switch. Instrument loads total .94 amps and if we add the
battery contactor at 1 amp this results in a 2 amp load that we would not
have control over. Leaving the question, is 6 amps enough to run the items
we will need for a safe completion of the flight. If the answer is yes, then
why not simply leave the load reduction to the pilot who would switch off
the non essential items and illiminate the E-buss. This gives the pilot the
option of turning on an item that might have been relligated to the main
buss but could be useful for a short period of time and then turned off
again.
It looks like the items we would place on our E-buss run between 5-6 amps.
So the loss of the 2 amps (instruments and contactor) buy simply staying
with the main bus and turning off items to reduce load would seem to make
sense.
So in the event we lost the main alt. ...we would... move the Master to Bat,
move the Aux Alt to on, turn off all unnecissary loads. At the airport,
battery still up, put the gear down and land.
Am I missing something?
Bob your critic of my thinking would be appreciated.
Regards,
Don Boardman
& Partner, Randy Bowers
Super Moose #130 M-14PF 400HP, MT-prop/beta, Aerocet 3500 amphibs
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | B&C 40 amp alternator : "F" tab? |
--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net>
Hi Bob,
Didn't get any instructions with alt. Which tab do you wire for field, horizontal
or vertical oriented tab or does it matter?
Thanks, Rick Fogerson
Boise, ID
RV3 wiring
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Brett Ferrell" <bferrell@123mail.net>
Bob/folks,
My heated pitot (AN315-1 from AeroInstruments) calls for MIL spec 22759/1 wire
to hook it up with. Where can I get a good source for a short length of this
specialty wire? Also, it claims to only draw 6.4-8 amps, so 18GA would be sufficient
correct? I expected to need bigger wire. Thanks.
Brett
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Myths and urban ledgends about motors |
--> AeroElectric-List message posted by: Benford2@aol.com
In a message dated 12/6/2003 1:43:54 PM Mountain Standard Time,
bob.nuckolls@cox.net writes:
>
> Hmmm . . . . okay, lets suppose we wanted to run this motor
> with the same load but needed to slow it down to 3000 rpm.
> What's a mother to do? We COULD add a resistor in series.
> How big a resistor? With a new counter EMF of 6 volts,
> we need to toss off 6 volts in total system resistance. With
> a load of 2A, this means total resistance
Ya got to LOVE this guy Bob...
Thanks again from all of us out in the internet world for all your time and
knowledge you share with us. Without you most of us would be scratching all the
hair off our thinning heads.
Ben Haas N801BH.
Jackson Hole Wy.
do not archive
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Pitot Tube Wire |
--> AeroElectric-List message posted by: Richard@Riley.net
I can't help with your question, but do you have a source for that
pitot? I don't find it with Google.
At 06:58 PM 12/6/03 -0500, you wrote:
>--> AeroElectric-List message posted by: "Brett Ferrell"
><bferrell@123mail.net>
>
>Bob/folks,
>
>My heated pitot (AN315-1 from AeroInstruments) calls for MIL spec 22759/1
>wire to hook it up with. Where can I get a good source for a short length
>of this specialty wire? Also, it claims to only draw 6.4-8 amps, so 18GA
>would be sufficient correct? I expected to need bigger wire. Thanks.
Message 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Phil Collins" <philc1@ix.netcom.com>
Brett
Tefzel wire I use meets MIL-W-22759 It's available from B & C Specialty,
Aircraft Spruce, Newark, etc... If you have some Tefzel wire around,
check the insulation. Should say 22759. On mine the number after the
slash is the gauge size. I used 18 gauge tefzel to my heated pitot (a
blade type out of a Piper) with no problems.
Phil
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Brett
Ferrell
Subject: AeroElectric-List: Pitot Tube Wire
--> AeroElectric-List message posted by: "Brett Ferrell"
<bferrell@123mail.net>
Bob/folks,
My heated pitot (AN315-1 from AeroInstruments) calls for MIL spec
22759/1 wire to hook it up with. Where can I get a good source for a
short length of this specialty wire? Also, it claims to only draw 6.4-8
amps, so 18GA would be sufficient correct? I expected to need bigger
wire. Thanks.
Brett
=
==
==
==
==
Message 16
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: B&C 40 amp alternator : "F" tab? |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
Rick,
The instructions that came with my B&C 40-amp alternator said simply to jump
the terminals together at the connector with a little jumper wire.
Wish I had a photo...I've got a photo of literally everything *but* this for
some reason. 8-)
)_( Dan
RV-7 N714D
http://www.rvproject.com
----- Original Message -----
From: "Rick Fogerson" <rickf@cableone.net>
Subject: AeroElectric-List: B&C 40 amp alternator : "F" tab?
> --> AeroElectric-List message posted by: "Rick Fogerson"
<rickf@cableone.net>
>
> Hi Bob,
> Didn't get any instructions with alt. Which tab do you wire for field,
horizontal or vertical oriented tab or does it matter?
> Thanks, Rick Fogerson
> Boise, ID
> RV3 wiring
>
>
Message 17
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: NiMH batteries |
--> AeroElectric-List message posted by: j1j2h3@juno.com
Does anyone know of a source for rechargeable lithium batteries in AA, C
or D sizes? Are the "non-rechargeable" lithium batteries truly
non-rechargeable, or is this a CYA statement from the manufacturers?
What happens if you try?
Jim Hasper - RV-7 just starting empennage (setting up shop in Franklin,
Tennessee)
Do not archive
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|