Today's Message Index:
----------------------
1. 03:25 AM - Serving Thermocouple wire (Dale Ensing)
2. 06:06 AM - Re: Slow make/break contacts (David E. Nelson)
3. 07:50 AM - Re: Thermocouple wire (Jim McBurney)
4. 11:44 AM - Re: Two Fuel pumps Z-19RB (Scott R. Shook)
5. 12:35 PM - Contactor Diodes (Dave VanLanen)
6. 01:02 PM - Re: Contactor Diodes (Bob White)
7. 01:40 PM - Re: Two Fuel pumps Z-19RB (jon@finleyweb.net)
8. 04:37 PM - Re: Contactor Diodes (Robert L. Nuckolls, III)
9. 05:04 PM - Alaskan STOL Contest (Robert L. Nuckolls, III)
10. 08:11 PM - Alternator Warranty Data Point - Rebuilt vs. New (Bill Schlatterer)
11. 09:03 PM - Re: Alternator Warranty Data Point - Rebuilt vs. New (Fiveonepw@aol.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: | Serving Thermocouple wire |
In my Boy Scout days many, many years ago we called this process "whipping".
I still do but serving is probably the more universal term.
Dale Ensing
> Interestingly enough, the only result from Google for "serving
> thermocouple wire" is to AC-21-99, Aircraft Wiring and Bonding
>
> Section 2 Chapter 16, Figure 16-14 shows the procedure and seems to
> match with the nautical terminology although I've don't recall hearing
> it before in reference to wiring.
> (http://www.casa.gov.au/rules/1998casr/021/021c99s2c16.pdf)
>
> Bob W. (Hanging on to the "bitter end".)
>
> Do not archive
> --
> N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> 3.8 Hours Total Time and holding
> Cables for your rotary installation - http://roblinstores.com/cables/
>
>
>
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 |
|
| Subject: | Re: Slow make/break contacts |
Very well, then. Boy, those marketing folks can sell anything! Thank you,
Bob.
Take care,
/\/elson
do not archive
~~ Lately my memory seems to be like a steel trap .... without any spring. ~~
On Tue, 17 Jun 2008, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@cox.net>
>
> At 01:15 PM 6/17/2008 -0500, you wrote:
>> <david.nelson@pobox.com>
>>
>>
>> Hi Bob,
>>
>> While I was looking for the S700 series specs on Carling's www site, I came
>> around a line of switches (F Series, in particular) with "slow make/break"
>> contacts. This struck me as odd. Under what circumstances would one want
>> to spread the contacts slowly?
>
> It's not that you WANT to, it's an artifact of an inexpensive
> switch. You can buy switches with very fast contact spreading
> velocities and fast/forceful closing characteristics but these
> will use a mechanism that is much more complicated than:
>
> http://aeroelectric.com/Pictures/Switches/Carling_Cutaway.jpg
>
> While the el-cheeso switch does have an spring loaded, over-center
> action, it's still classed as a slow make-break device because
> you can "tease" it open and "sneak up" on a closure by holding
> the handle and preventing it from exploiting the over-center
> behavior.
>
> In a fast make/break device, you can't tease it. Once past the
> point of no return, the switch snaps to the new position with
> gusto.
>
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
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: Thermocouple wire |
Yes, WE did!
Do not archive
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: | Two Fuel pumps Z-19RB |
Correct me if I am wrong here, but this is my understanding of a Fuel
Injected systems such as Subaru's.
On a continuous loop system such as the Subaru FI system, doesn't the EFI
computer control the mixture (rich/lean) and not the fuel pumps? The fuel
system pumps gallons of fuel through in a matter of minutes and the EFI
system allows only a small portion of that fuel to be released by the
injectors into the combustion chamber.
Having both pumps on during takeoff, landing, and other low altitude
maneuvers is only good measure in case of a failure on the single pump.
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Sam
Hoskins
Sent: Monday, 16 June, 2008 06:13
Subject: Re: AeroElectric-List: Two Fuel pumps Z-19RB
I think it might be better to only have one fuel pump at a time, to prevent
overloading the pressure regulator. I don't know how much flow the P.R. can
handle, since I have not yet powered up the system. If the regulator can
handle two pumps, then no problem. However, if it can't, then running two
pumps may adversely affect the mixture.
I recently saw an accident report involving a Lancair IV where it is
speculated that two pumps were running at once and the engine lost power
because of an excessively rich condition.
Anyway, that's my reasoning.
Sam Hoskins
Quickie Blog <http://www.samhoskins.blogspot.com/>
Quickie Website <http://home.mchsi.com/%7Eshoskins/index.htm>
On Mon, Jun 16, 2008 at 7:52 AM, Joe <fran5sew@banyanol.com> wrote:
Sam,
Why are you using a double pole switch for "System B Engine Secondary" ECU
instead of a single pole switch?
Suggestion for Ignition Coil +12V Supply: connect switch terminals 1 & 4
together and terminals 3 & 6 together for redundancy.
Would it hurt anything to have two pumps running at once? It would greatly
simplify the circuit to have one switch for each pump, with each switch
having 3 positions: source A, OFF, source B. It would be up to the pilot to
make sure that only one pump in turned on at a time.
If you absolutely have to prevent both pumps from running at once, let me
know and I will draw a circuit using either 4 switches or else 2 switches
plus diodes.
Joe
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: | Contactor Diodes |
I am reading Chapter 11 of the AeroElectric manual, pp. 11-20 and 11-21
regarding battery and starter contactors, and I am having trouble
understanding the use of diodes for spike protection.
In figure 11-20 for a battery contactor, the diode is connected between the
coil terminal and the large battery terminal. When the contactor switch is
opened, and the magnetic field of the coil collapses, what prevents an
electrical spike from traveling directly out of the coil back through the
22AWG wire to the master switch, bypassing the diode, which is shown as
being wired "in parallel" to the coil?
In figure 11-21 for a starter contactor, the direction of the diode appears
to prevent a flow to ground, where there are no electrical components to
protect. Again, what would prevent the spike from traveling back through
the 20AWG wire to the starter switch, bypassing the diode?
I'm sure these are "dumb" questions, but I'm not very quick at picking up
some of these things as some folks are. I would appreciate help in
understanding it.
Thanks,
Dave Van Lanen
Do Not Archive
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: Contactor Diodes |
On Wed, 18 Jun 2008 14:29:23 -0500
"Dave VanLanen" <davevanlanen@sbcglobal.net> wrote:
> I am reading Chapter 11 of the AeroElectric manual, pp. 11-20 and 11-21
> regarding battery and starter contactors, and I am having trouble
> understanding the use of diodes for spike protection.
>
> In figure 11-20 for a battery contactor, the diode is connected between the
> coil terminal and the large battery terminal. When the contactor switch is
> opened, and the magnetic field of the coil collapses, what prevents an
> electrical spike from traveling directly out of the coil back through the
> 22AWG wire to the master switch, bypassing the diode, which is shown as
> being wired "in parallel" to the coil?
>
> In figure 11-21 for a starter contactor, the direction of the diode appears
> to prevent a flow to ground, where there are no electrical components to
> protect. Again, what would prevent the spike from traveling back through
> the 20AWG wire to the starter switch, bypassing the diode?
>
> I'm sure these are "dumb" questions, but I'm not very quick at picking up
> some of these things as some folks are. I would appreciate help in
> understanding it.
>
> Thanks,
> Dave Van Lanen
>
> Do Not Archive
>
Hi Dave,
When you interrupt the current flow through a coil, there is a voltage
produced that is proportional to the speed that the current changes. It
is also the opposite polarity to the voltage that was applied to
generate the current flow in the first place. What the diode does is
provide a low impedance load for the reverse polarity spike. Voltage
will be limited to the forward voltage of the diode, and current flow
will decay more slowly. That's why the coil drop out time is increased
when the spike protection is used.
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
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: | Two Fuel pumps Z-19RB |
=0AHi Scott - Good Question but a long answer... :-)=0A=0A =0A=0AWith an OE
M EFI system (i.e. Subaru), there are two modes to consider - Open and Clos
ed loop. In Closed loop, the oxygen sensor output is being referenced by t
he ECU and the mixture is adjusted to obtain the optimal setting (stoichiom
etric). In Open loop, lookup table data values are used to set the mixture
(based on RPM, atmospheric pressure, and ??? (I can't remember but it seem
s like there is more..)). In both cases, the mixture is varied by the amou
nt of time the injectors are open (pulse width). In most all modes of flig
ht, the OEM ECU is in Open loop mode. For example; the EJ-22 Legacy ECU go
es into Open loop mode at about 3000 rpm (if memory serves). A number of pe
ople running the OEM system were varying fuel pressure to adjust the mixtur
e in flight.=0A=0A =0A=0AThe RWS system (EC2) does not use an oxygen sensor
- rather only a set of lookup tables. These values are very easy to set by
the operator (in flight or on the ground) plus a mixture "dial" is also pr
ovided to set the mixture during atypical situations (i.e. idle when very c
old (richen), long-hot climb (richen for cooling), etc...).=0A=0A =0A=0AIn
the case of the OEM Open Loop and all the time for the RWS system, increasi
ng the fuel pressure will result in more fuel being injected for the given
injector pulse. Higher pressure - richer mixture, lower pressure - leaner m
ixture. So, going back to the conversation; when fuel pump one is running,
I see about 36 psi. Turning on pump two increases the presure by about 3ps
i which affects the mixture (richens) but it is by such a small percentage
that it is really not noticeable (at least not on the air/fuel ratio guage
that I use).=0A=0A =0A=0AThe issue that I believe Sam is worried about is h
is fuel pressure regulator being unable to 'bypass' enough fuel when both p
umps are on resulting in the pressure climbing and the mixture getting rich
er and richer.=0A=0A =0A=0AJon=0A=0A-----Original Message-----=0AFrom: "Sco
tt R. Shook" <sshook@cox.net>=0ASent: Wednesday, June 18, 2008 2:24pm=0ATo:
aeroelectric-list@matronics.com=0ASubject: RE: AeroElectric-List: Two Fuel
pumps Z-19RB=0A=0A=0A=0A=0A=0A=0A=0A=0ACorrect me if I am wrong here, but
this is my understanding of a Fuel Injected systems such as Subaru=99
s. =0A=0A =0A=0AOn a continuous loop system such as the Subaru FI system, d
oesn=99t the EFI computer control the mixture (rich/lean) and not the
fuel pumps? The fuel system pumps gallons of fuel through in a matter of
minutes and the EFI system allows only a small portion of that fuel to be r
eleased by the injectors into the combustion chamber.=0A=0A =0A=0AHaving bo
th pumps on during takeoff, landing, and other low altitude maneuvers is on
ly good measure in case of a failure on the single pump.=0A=0A=0A=0A
=0AScott R. Shook =0ARV-7A (Building) =0AN696JS (R
eserved) =0A=0A=0A=0A=0A=0A=0A=0AFrom: owner-aeroelectric-list-server@matro
nics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Sam Hoskins=0ASent: Monday, 16 June, 2008 06:13=0ATo: aeroelectric-list@ma
tronics.com=0ASubject: Re: AeroElectric-List: Two Fuel pumps Z-19RB=0A=0A
=0A=0AI think it might be better to only have one fuel pump at a time, to p
revent overloading the pressure regulator. I don't know how much flow the
P.R. can handle, since I have not yet powered up the system. If the regula
tor can handle two pumps, then no problem. However, if it can't, then runn
ing two pumps may adversely affect the mixture. =0A=0AI recently saw an acc
ident report involving a Lancair IV where it is speculated that two pumps w
ere running at once and the engine lost power because of an excessively ric
h condition.=0A=0AAnyway, that's my reasoning.=0A=0ASam Hoskins=0A[http://w
ww.samhoskins.blogspot.com/] Quickie Blog=0A[http://home.mchsi.com/~shoskin
s/index.htm] Quickie Website=0A=0A=0A=0AOn Mon, Jun 16, 2008 at 7:52 AM, Jo
e <fran5sew@banyanol.com> wrote:=0A=0A=0A=0A=0A=0ASam,=0A=0A =0A=0AWhy are
you using a double pole switch for "System B Engine Secondary" ECU instead
of a single pole switch?=0A=0A =0A=0ASuggestion for Ignition Coil +12V Sup
ply: connect switch terminals 1 & 4 together and terminals 3 & 6 together f
or redundancy.=0A=0A =0A=0AWould it hurt anything to have two pumps running
at once? It would greatly simplify the circuit to have one switch for eac
h pump, with each switch having 3 positions: source A, OFF, source B. It w
ould be up to the pilot to make sure that only one pump in turned on at a t
ime.=0A=0A =0A=0AIf you absolutely have to prevent both pumps from running
at once, let me know and I will draw a circuit using either 4 switches or e
lse 2 switches plus diodes.=0A=0A =0A=0AJoe=0A=0A=0A =0A =0A =0A=0A =0A =0A
=0A=0A=0A=0A=0A=0A=0Ahttp://www.matronics.com/Navigator?AeroElectric-List
=0A=0A=0A=0Ahttp://forums.matronics.com=0A=0A=0A=0A=0Ahttp://www.matronics.
nics.com/Navigator?AeroElectric-List] http://www.matronics.com/Navigator?Ae
://www.matronics.com/contribution] http://www.matronics.com/contribution=0A
============0A=0A
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: | Re: Contactor Diodes |
At 02:29 PM 6/18/2008 -0500, you wrote:
>I am reading Chapter 11 of the AeroElectric manual, pp. 11-20 and 11-21
>regarding battery and starter contactors, and I am having trouble
>understanding the use of diodes for spike protection.
>
>In figure 11-20 for a battery contactor, the diode is connected between
>the coil terminal and the large battery terminal. When the contactor
>switch is opened, and the magnetic field of the coil collapses, what
>prevents an electrical spike from traveling directly out of the coil back
>through the 22AWG wire to the master switch, bypassing the diode, which is
>shown as being wired in parallel to the coil?
>
>In figure 11-21 for a starter contactor, the direction of the diode
>appears to prevent a flow to ground, where there are no electrical
>components to protect. Again, what would prevent the spike from traveling
>back through the 20AWG wire to the starter switch, bypassing the diode?
>
>I m sure these are dumb questions, but I m not very quick at picking up
>some of these things as some folks are. I would appreciate help in
>understanding it.
No problem Dave,
See:
http://www.aeroelectric.com/articles/spike.pdf
http://www.aeroelectric.com/articles/spikecatcher.pdf
If these don't answer or satisfactorily explain
then get back with us here on the List.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
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: | Alaskan STOL Contest |
A reader sent me this video. Impressive enough to dedicate
some server space to it. You're invited to view it at:
http://www.aeroelectric.com/Pictures/Video/Alaska_STOL.wmv
This is a BIG file, about 4.5 Mb so if you're saddled with
dial-up, be aware that it will take awhile.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
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: | Alternator Warranty Data Point - Rebuilt vs. New |
Just a data point I thought might be interesting. I recently had the
opportunity to review warranty rates on several of the major rotating
electrical rebuilders for alternator warranty returns through autopart
stores. Low number was 9.6% and high was 18%. This includes wholesale as
well as retail sales with no data as to specific cause. The manufacturers
all report "true" warranty rates at 5%- 8% on product tested after it was
returned. Warranty on New Alternators was running 5.6% so they were
substantially better. No numbers on the "true" rates for New product but I
would think it about 3%. These numbers are very much in line with
historical rates we saw several years ago. Also should note that warranty
rates do vary considerably by specific application and these numbers apply
to the category and not a particular unit.
It is interesting that while the technology involved in the rebuilding and
testing processes has improved over the past few years, the actual return
rates have not reflected the benefits of better processes. ( I attribute
that to "trial and error" troubleshooting on the retail side.)
I would interpret this to say that if you are using an automotive
alternator, the odds of a failure in the first few hours of operation are
about double for rebuilt versus new and 1 bad rebuilt unit out of every
10-15 should be a normal expectation. For our purposes,... buy new if you
can.
It would be very interesting to know what the return rate and actual failure
rate is on B&C units after they have done all the extra tuning, balancing,
etc. Maybe Bob could get that number for comparison?
Bill S
7a Finishing
Z13 P-mag B&C
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: | Re: Alternator Warranty Data Point - Rebuilt vs. New |
In a message dated 6/18/2008 10:12:40 P.M. Central Daylight Time,
billschlatterer@sbcglobal.net writes:
It would be very interesting to know what the return rate and actual failure
rate is on B&C units after they have done all the extra tuning, balancing,
etc.
>>>>>>>>>>>>>>>>
My personal track record is nearing 600 hrs on 2 B&C L40s (2 planes) and
they are both still kicking coulombs with nary a hickup!
Soliciting other love/war stories-
Mark
**************Gas prices getting you down? Search AOL Autos for
fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007)
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! --
|