Today's Message Index:
----------------------
1. 06:48 AM - Re: Alternator output (Robert L. Nuckolls, III)
2. 07:07 AM - Re: AeroElectric-List Digest: 11 Msgs - 07/11/05 (Dave Harmon)
3. 08:16 AM - Internal regulation (Kevin Horton)
4. 08:58 AM - Re: Internal regulation (Hinde, Frank George (Corvallis))
5. 09:20 AM - Re: AeroElectric-List Digest: 11 Msgs - 07/11/05 (Glaeser, Dennis A)
6. 09:53 AM - Re: Internal regulation (Phil Birkelbach)
7. 05:57 PM - split pin connectors ()
8. 06:21 PM - Re: ICOM PTT ()
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: | Re: Alternator output |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 09:04 AM 7/8/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "Vern W." <vernw@ev1.net>
>
> I'd like to ask a simple follow-up question here, Bob.
> In a scenario of Z13/8 with only the one main battery existing in the
>system, if (for example) a lug breaks on the battery and it's taken out of
>the system, will the main alternator continue to power the system? Or
>without the battery in the system, would there be a voltage runaway and the
>main alternator would have to be taken offline? ... (If that were the case,
>then the SD8 would have no chance of coming alive by itself).
> If the main alternator WOULD continue to power the system within the
>proper voltage range (due to it's regulator controlling the voltage?), and
>the SD8 is then switched on, would the SD8 come alive using the voltage from
>the main alternator as the exciter? And then would the SD8 continue to power
>the system on it's own without a battery in the system?
> What I'm trying to get straight in my head is the various failure
>scenarios possible and how the "surviving" components are expected to react.
A worthwhile endeavor. Most alternators will continue to produce
power with a disconnected battery as long as they don't get "stalled".
A wound field alternator needs a sample of it's own output to produce
power . . . load it severely (in excess of it's ratings) just for
a few milliseconds and it may quit and stay dead.
Battery terminal breakage (or battery contactor failure) is
relatively rare. I've never encountered one personally or known
one who has. I've replaced dozens of contactors that failed in
pre-flight but never one that failed in flight.
Is the risk zero? No, just small. If this worries you, then
perhaps a dual battery installation is in order either in the
form of Z-30 implementation or perhaps Z-14. Keep in mind that
hundreds of thousands of spam cans have flown for nearly
a century with electrical systems being WAAAAYYYY down on the
list of contributing events for the entire constellation of
accident scenarios.
When I walk up to a rental airplane and make ready to launch,
I don't care if ANYTHING on the panel is getting power. I have
tools in my flight back and the mindset that I intend to arrive
at the airport of original destination with the airplane in
a "J-3 Mode" of operation if necessary.
I'll suggest it's much easier to prepare yourself for the
worst kinds of electrical failure than it is to design a system that
will NEVER fail. The worst case is that your "bullet proof"
system will fail you anyhow and you'll find yourself ill-prepared
to cope with it.
What kind of airplane are you building? How is it electrically
dependent? How do you plan to use the airplane? How much are
YOU electrically dependent? The road to comfortable flight
is lined with answers to these questions even if some answers
do not offer 99.999999 or even 90.0 percent reliability.
Bob . . .
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: AeroElectric-List Digest: 11 Msgs - 07/11/05 |
"AeroElectric-List Digest List" <aeroelectric-list-digest@matronics.com>
--> AeroElectric-List message posted by: "Dave Harmon" <vagabondpa15@verizon.net>
Can we go over again why it's not rec. to use internal regulation on
alternators.
Dave
----- Original Message -----
From: "AeroElectric-List Digest Server"
<aeroelectric-list-digest@matronics.com>
Subject: AeroElectric-List Digest: 11 Msgs - 07/11/05
> *
>
> ==================================================
> Online Versions of Today's List Digest Archive
> ==================================================
>
> Today's complete AeroElectric-List Digest can also be found in either of
> the
> two Web Links listed below. The .html file includes the Digest formatted
> in HTML for viewing with a web browser and features Hyperlinked Indexes
> and Message Navigation. The .txt file includes the plain ASCII version
> of the AeroElectric-List Digest and can be viewed with a generic text
> editor
> such as Notepad or with a web browser.
>
> HTML Version:
>
>
> http://www.matronics.com/digest/aeroelectric-list/Digest.AeroElectric-List.2005-07-11.html
>
> Text Version:
>
>
> http://www.matronics.com/digest/aeroelectric-list/Digest.AeroElectric-List.2005-07-11.txt
>
>
> ================================================
> EMail Version of Today's List Digest Archive
> ================================================
>
>
> AeroElectric-List Digest Archive
> ---
> Total Messages Posted Mon 07/11/05: 11
>
>
> Today's Message Index:
> ----------------------
>
> 1. 05:57 AM - Diodes 101 (Lui Esc)
> 2. 06:33 AM - Re: Split Pin Connectors? ()
> 3. 07:14 AM - Re: Diodes 101 (chad-c_sip@stanfordalumni.org)
> 4. 07:14 AM - Re: Diodes 101 (Robert L. Nuckolls, III)
> 5. 07:19 AM - Re: Z13 with B&C Alt/Reg combination ? (Robert L.
> Nuckolls, III)
> 6. 08:33 AM - Re: Re: Help - low voltage - update (Robert L.
> Nuckolls, III)
> 7. 08:35 AM - Re: Help - low voltage - update (P.S.) (Robert L.
> Nuckolls, III)
> 8. 09:04 AM - Re: alternator testing (Mark & Lisa)
> 9. 09:06 AM - Re: 24V Starter (Mark & Lisa)
> 10. 09:32 AM - Overvoltage and PM alternators (Jon Goguen)
> 11. 05:54 PM - Fw: Diagnostic voltages for Alternator (Rick Fogerson)
>
>
> ________________________________ Message 1
> _____________________________________
>
>
> Time: 05:57:58 AM PST US
> From: "Lui Esc" <f1rocketbuilder@hotmail.com>
> Subject: AeroElectric-List: Diodes 101
>
> --> AeroElectric-List message posted by: "Lui Esc"
> <f1rocketbuilder@hotmail.com>
>
> Does anyone knows if there is any document that covers Diodes by
> themselves?
> I have a few gray areas understanding which diode to use, identify,
> rating,
> etc.
>
> There are several diodes shown on the Aeroelectric diagrams but I can't
> see
> part numbers to reference. Ex. a diode between the essential bus and the
> primary bus, also, diode on the starter seleniod.
>
> I need to use some diodes in other areas but, I am still learning and want
> to be sure I use/order the correct stuff.
>
> I sent an email to Bob via his web site, but I did not hear back from him.
> I just learned about this forum, so I subscribed to the Digest.
>
> Thanks,
> LE
>
>
> Comments/Questions: Building a F-1 Rocket. Love your publications,
> learned
> a lot thanks to you. But continue trying to learn and understand the
> electric side as much as I can since I am doing the wiring by myself. Do
> you have a document that covers Diodes by themselves? I have a gray area
> trying to identify part number or diode required on certain areas
> mentioned
> in your publications. Ex. a diode between the essential bus and the
> primary
> bus and others. Thanks. Luis
>
>
> ________________________________ Message 2
> _____________________________________
>
>
> Time: 06:33:02 AM PST US
> From: <bakerocb@cox.net>
> Subject: AeroElectric-List: Re: Split Pin Connectors?
>
> --> AeroElectric-List message posted by: <bakerocb@cox.net>
>
> Aeroelectric-list message previously posted by Bob Nuckolls
>
> <<....skip....What's the brand and model number of the autopilot?
> One can often deduce the connector technology by knowing
> who made the system. Manufacturers often have a stable
> of connectors-of-choice. Getting a peek at the installation/
> maintenance manual for the autopilot may help. Was the
> autopilot installed as a Beechcraft option? If so, I
> may have access to data in the company archives that
> would help. Bob . . .>>
>
> 7/1/2005
>
> Hello Bob Nuckolls, I am the owner of the Beechcraft Sierra with autopilot
> problems that OC Baker referred to . In answer to your response I can
> provide the following additional data, and any help/suggestions you
> provide
> would be greatly appreciated.
>
> The POH for the Beechcraft Sierra C24R depicts an autopilot in the
> instrument panes for all a/c after serial no. MC 571. My a/c, serial no.
> is
> MC 778 mfg'd in 1982. However, the POH does not provide any information on
> the autopilot itself. Neither the logs nor the weight and balance sheets
> mention an autopilot add-on. I therefore am led to believe that it was a
> factory install at time of delivery. The autopilot itself is a Century IIB
> mfg'd by Flight Systems, Inc. PO Box 610, Mineral Wells, TX 76067. As to
> "split pin connectors", another Sierra owner offers that the techie was
> referring to the "Little Blue Plugs used by Century for many of their
> autopilot connections. They have stamped receptor pins rather than solid
> ones."
>
> Does any of this additional info help shed some light on the problem?
> Thanks
> for you help. George Philipps
>
>
> ________________________________ Message 3
> _____________________________________
>
>
> Time: 07:14:15 AM PST US
> From: chad-c_sip@stanfordalumni.org
> Subject: Re: AeroElectric-List: Diodes 101
> Z-USANET-MsgId: XID223JgkoNs0424X37
>
> --> AeroElectric-List message posted by: chad-c_sip@stanfordalumni.org
>
> A good ol' Google Search on "diode tutorial" brought up this link:
>
> http://www.americanmicrosemi.com/tutorials/diode.htm
>
> It seemed like a good introduction. At least from that you know the
> terminology used when describing a diode. And now you can compare the
> performance of different beasties. The only other thing I'd add is that
> "full
> wave rectifiers" are really just 4 diodes laid out nose-to-tail in a
> diamond
> pattern. We tend to talk about rectifiers as power diodes are they already
> come in larger power packages ready to be attached to a heat sink. And
> there's
> no reason you can't simply use only one of the 4 diodes in the package.
>
> Good luck.
>
> Chad
>
> Chad Sipperley
> Lancair IV-P turbine (under construction)
> Phoenix, AZ
>
> ------ Original Message ------
> From: "Lui Esc" <f1rocketbuilder@hotmail.com>
> Subject: AeroElectric-List: Diodes 101
>
>> --> AeroElectric-List message posted by: "Lui Esc"
> <f1rocketbuilder@hotmail.com>
>>
>> Does anyone knows if there is any document that covers Diodes by
> themselves?
>> I have a few gray areas understanding which diode to use, identify,
>> rating,
>
>> etc.
>>
>> There are several diodes shown on the Aeroelectric diagrams but I can't
>> see
>
>> part numbers to reference. Ex. a diode between the essential bus and the
>> primary bus, also, diode on the starter seleniod.
>>
>> I need to use some diodes in other areas but, I am still learning and
>> want
>> to be sure I use/order the correct stuff.
>>
>> I sent an email to Bob via his web site, but I did not hear back from
>> him.
>
>> I just learned about this forum, so I subscribed to the Digest.
>>
>> Thanks,
>> LE
>>
>>
>> Comments/Questions: Building a F-1 Rocket. Love your publications,
>> learned
>
>> a lot thanks to you. But continue trying to learn and understand the
>> electric side as much as I can since I am doing the wiring by myself.
>> Do
>> you have a document that covers Diodes by themselves? I have a gray area
>> trying to identify part number or diode required on certain areas
>> mentioned
>
>> in your publications. Ex. a diode between the essential bus and the
>> primary
>
>> bus and others. Thanks. Luis
>>
>>
>>
>>
>>
>>
>>
>
>
> ________________________________ Message 4
> _____________________________________
>
>
> Time: 07:14:15 AM PST US
> From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Subject: Re: AeroElectric-List: Diodes 101
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> At 07:56 AM 7/11/2005 -0500, you wrote:
>
>>--> AeroElectric-List message posted by: "Lui Esc"
>><f1rocketbuilder@hotmail.com>
>>
>>Does anyone knows if there is any document that covers Diodes by
>>themselves?
>>I have a few gray areas understanding which diode to use, identify,
>>rating,
>>etc.
>>
>>There are several diodes shown on the Aeroelectric diagrams but I can't
>>see
>>part numbers to reference. Ex. a diode between the essential bus and the
>>primary bus, also, diode on the starter seleniod.
>>
>>I need to use some diodes in other areas but, I am still learning and want
>>to be sure I use/order the correct stuff.
>>
>>I sent an email to Bob via his web site, but I did not hear back from him.
>>I just learned about this forum, so I subscribed to the Digest.
>
> ANY rectifier diode that LOOKs like this will do:
>
> http://www.aeroelectric.com/Pictures/s401-25.jpg
>
> Here's an excerpt from the Radio Shack catalog:
>
> http://www.aeroelectric.com/Pictures/RS_Diodes.jpg
>
> Note that it offers an 276-1185 full wave bridge rectifier
> which is suited for use as the e-bus normal feed diode illustrated
> above
>
> It also offers the 1N540X series diodes which
> are my favorites for use on contactors. These are
> mechanically more robust and easy to work with.
>
> See:
>
> http://www.aeroelectric.com/Pictures/s701-1l.jpg
> http://www.aeroelectric.com/Pictures/s701-2.jpg
>
> If the 5400 series are too heavy mechanically
> for your application, consider the 1N400x series
> on the same page.
>
> A typical useage for the 4000 series is shown
> here:
>
> http://www.aeroelectric.com/Pictures/s704inst.jpg
>
> Ratings for diodes used as spike catchers is
> not critical. Only the e-bus normal feed diode
> needs to have some electrical heftiness and
> the 276-1185 or any of its siblings will be fine.
> If it comes in this package, then it's big enough.
>
> See note 12 of
>
> http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf
>
> and
>
> http://aeroelectric.com/articles/spikecatcher.pdf
>
> Bob . . .
>
>
> ________________________________ Message 5
> _____________________________________
>
>
> Time: 07:19:17 AM PST US
> From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Subject: Re: AeroElectric-List: Z13 with B&C Alt/Reg combination ?
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> At 10:35 PM 7/10/2005 -0500, you wrote:
>
>>--> AeroElectric-List message posted by: "Bill Schlatterer"
>><billschlatterer@sbcglobal.net>
>>
>>
>>Bob, am I missing something? I was looking for the Z13 diagram with the
>>B&C
>>alt/reg combination and can't seem to find it. Would be great to see with
>>P-mag but assume you can just add in the R11C Z13 w/P-Mags.
>>
>>Bill S
>>RV7a Arkansas
>
> The z-figures are crafted to illustrate architectures, not to make
> specific recommendations for use of parts. I COULD craft a dozen
> z-13's, each depicting a different regulator, alternator, etc.
>
> Usage of the LR-3 series devices is illustrated in several
> other z-figures . . . if that's your regulator of choice for
> Z-13, then you'll need to draw out your own power distribution
> diagram modified to include your features of choice.
>
> EVERYONE should do their own power distribution diagrams to
> exactly match their project. The Z-figures are only a guide to
> get you started.
>
> Bob . . .
>
>
> ________________________________ Message 6
> _____________________________________
>
>
> Time: 08:33:48 AM PST US
> From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Subject: Re: AeroElectric-List: Re: Help - low voltage - update
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> Before you pull anything off the airplane, let's do a good job of
> diagnosis to KNOW which part needs attention. I've got a piece nearly
> finished on alternator system troubleshooting that I'll publish on
> the website in next day or so along with links from this list.
>
> Bob . . .
>
> At 06:38 AM 7/9/2005 -0400, you wrote:
>
>>--> AeroElectric-List message posted by: "Mike & Lee Anne Wiebe"
>><mwiebe@sympatico.ca>
>>
>>Thx Jim - that makes some sense. I think it's time to pull the
>>alternator and check the diode bridge.
>>
>>You raise another interesting idea. What do you think of this scenario?
>>I recently changed the battery to a smaller one (had the Odessey 680
>>ready to go for the new aircraft, so when it came time for a
>>"Knuckoll's change-out" I replaced the large B&C with the Odessey). The
>>alternator is the larger B&C, so alternator load shouldn't be the
>>problem (presuming the diodes are OK). Do you think a change to a
>>smaller battery might have changed the ability of the system to "sink"
>>the pulsing load of the strobes, and make voltage vary more?
>>
>>I guess it's also possible that its done this since new, and I've just
>>never noticed. Though somehow I think I would have before now.
>>
>>Mike
>>
>>
>>--
>>
>>
>>-- incoming mail is certified Virus Free.
>
>
> Bob . . .
>
>
> --------------------------------------------------------
> < Throughout history, poverty is the normal condition >
> < of man. Advances which permit this norm to be >
> < exceeded -- here and there, now and then -- are the >
> < work of an extremely small minority, frequently >
> < despised, often condemned, and almost always opposed >
> < by all right-thinking people. Whenever this tiny >
> < minority is kept from creating, or (as sometimes >
> < happens) is driven out of a society, the people >
> < then slip back into abject poverty. >
> < >
> < This is known as "bad luck". >
> < -Lazarus Long- >
> <------------------------------------------------------>
> http://www.aeroelectric.com
>
>
> ________________________________ Message 7
> _____________________________________
>
>
> Time: 08:35:20 AM PST US
> From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Subject: AeroElectric-List: Re: Help - low voltage - update (P.S.)
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> PS have you conducted the tests described in:
>
> http://www.aeroelectric.com/articles/Alternators/Alternator_Test.pdf
>
> This is the best way to isolate the problem with respect to
> regulation or alternator issues . . .
>
> B-
>
> Before you pull anything off the airplane, let's do a good job of
> diagnosis to KNOW which part needs attention. I've got a piece nearly
> finished on alternator system troubleshooting that I'll publish on
> the website in next day or so along with links from this list.
>
> Bob . . .
>
>
> ________________________________ Message 8
> _____________________________________
>
>
> Time: 09:04:07 AM PST US
> From: "Mark & Lisa" <marknlisa@hometel.com>
> Subject: Re: AeroElectric-List: alternator testing
>
> --> AeroElectric-List message posted by: "Mark & Lisa"
> <marknlisa@hometel.com>
>
> Bob,
>
> Thanks again!
>
> Mark & Lisa Sletten
> Legacy FG N828LM
> http://www.legacyfgbuilder.com
>
> DO NOT ARCHIVE
>
>
> ________________________________ Message 9
> _____________________________________
>
>
> Time: 09:06:32 AM PST US
> From: "Mark & Lisa" <marknlisa@hometel.com>
> Subject: Re: AeroElectric-List: 24V Starter
>
> --> AeroElectric-List message posted by: "Mark & Lisa"
> <marknlisa@hometel.com>
>
> Jim,
>
> Thank you too!
>
> Mark & Lisa Sletten
> Legacy FG N828LM
> http://www.legacyfgbuilder.com
>
> DO NOT ARCHIVE
>
>
> ________________________________ Message 10
> ____________________________________
>
>
> Time: 09:32:25 AM PST US
> From: Jon Goguen <jon.goguen@umassmed.edu>
> Subject: AeroElectric-List: Overvoltage and PM alternators
>
> --> AeroElectric-List message posted by: Jon Goguen
> <jon.goguen@umassmed.edu>
>
> Hi All,
>
> My first post to the list. I'm co-builder of the Kitfox described in
> the signature along with my uncle Nelson Goguen. Most of what remains
> to get the ship finished is electrical so here I am. I've read Bob's
> Aeroeletric Connection and found it very informative, and very much
> like his design philosophy and the principle that we should build
> better than certified. I've had a lifelong interest in electronics
> and instrumentation, and hope I might be able to make some useful
> contributions to the community. Thanks in advance for all your relies.
>
> Now down to business. I'm wondering about the importance of
> overvoltage protection on PM alternators. Without a field coil,
> extreme voltage runaway shouldn't be possible with these machines.
> They do produce 30 volts or so, which could certainly be damaging if it
> passed through the regulator, but I believe the regulators use a phase
> control shunt-based design. If so, the shunting SCRs would virtually
> always fail in the conducting mode, which would give low rather than
> high voltage output. Does anyone know of a documented case of
> overvoltage problems with a properly installed PM alternator?
>
> Given the simplicity and reliability of PM alternators, it would seem
> that the regulator is by far the weakest link in the charging system.
> This would argue for a dual regulator design. I don't know enough
> about the regulator innards to know if paralleling two of them would
> result in undesirable interactions, but I suspect that it might. This
> could be avoided by simply providing means to switch between the two
> regulators.
>
> So:
>
> Does OV protection really make sense for a PM alternator system?
>
> Would a dual-regulator design provide a worthwhile enhancement in
> reliability?
>
> Thanks!
>
> Jon
>
> Jon Goguen
> jon.goguen@umassmed.edu
> Central Massachusetts
> Kitfox Series V Rotax 912S / N456JG (reserved)
> Complete except for electrics and avionics
>
>
> ________________________________ Message 11
> ____________________________________
>
>
> Time: 05:54:23 PM PST US
> From: "Rick Fogerson" <rickf@cableone.net>
> Subject: AeroElectric-List: Fw: Diagnostic voltages for Alternator
>
> --> AeroElectric-List message posted by: "Rick Fogerson"
> <rickf@cableone.net>
>
> Hi Bob,
> If you answered this already I must have missed it. Would appreciate some
> numbers
> as I don't have a clue what a high field voltage would be, etc.
> Rick
> ----- Original Message -----
> From: Rick Fogerson
> Subject: Diagnostic voltages for Alternator
>
>
> Hi Bob,
> I put a jack in my airplane a la Page Z-6 for alternator diagnostics. I
> have B&C's
> alternator and voltage regulator. Could I get some numbers/ranges to the
> voltages for the descriptive words in the following paragraphs:
>
> Paragraph (a) alt output is zero when the bus voltage is ______?
>
> Paragraph (e) If the field voltage is high_____? and does not drop
> significantly_____?
> when engine rpm increases but bus voltage seems normal under light load
> and sags under heavy loads....
>
> What would be the voltage regulators normal set point____?
>
>
> Thanks Bob and have a great 4th of July,
> Rick Fogerson
> RV3 done, making POH
> Boise, ID
>
>
>
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: | Internal regulation |
--> AeroElectric-List message posted by: Kevin Horton <khorton01@rogers.com>
On 12 Jul 2005, at 10:06, Dave Harmon wrote:
> --> AeroElectric-List message posted by: "Dave Harmon"
> <vagabondpa15@verizon.net>
>
> Can we go over again why it's not rec. to use internal regulation on
> alternators.
> Dave
Dave,
The first big question is whether you want to have over voltage
protection or not. Some folks who have never heard of any over
voltage cases on cars, figure that an automotive alternator with
internal regulation is reliable enough that they don't worry about an
over voltage. But, there was a message on this list a while back
from a guy who had an automotive alternator on his aircraft that
would go into an over voltage condition as soon as he selected it
on. So, over voltages do happen.
If your avionics are cheap, or you have enough money that you are
prepared to risk them, you could go without over voltage protection.
If you want over voltage protection, and you use an externally
regulated alternator, the over voltage protection device can simply
cut the power between the voltage regulator and the alternator
field. This line only has small current in it, so there is no
problem to chop the power if an over voltage ever occurs.
But, if you have an internally regulated alternator, the wire from
the voltage regulator to the field is buried inside the alternator -
you can't get at it. So, the only way to deal with an over voltage
is to have a contactor in the alternator output that is opened
automatically if the alternator runs away. This contactor will have
to open when the alternator is supplying as much current as it can
possibly do, and there is some question about whether the contactor
will actually reliably cut the alternator output, or whether it might
arc internally and weld closed.
There have also been a few unexplained problems with internally
regulated alternators sold by Van's aircraft if they are installed
with the over voltage protection sold by B&C Specialties. There have
been several events where something happened that fried the internal
regulator, but no one has been able to figure out the cause, so we
have no fix yet.
If you use an externally regulated alternator, you can use the over
voltage protection sold by B&C Specialties (and designed by Bob
Nuckolls). A small number of people have a philosophical problem
with the way it shorts out the field line to cause the field CB to
pop open, but no one has been able to demonstrate a real problem with
the design. It is simple, and it works.
So, my advice: if you want over voltage protection, go with an
externally regulated alternator. If you judge the cost and hassle of
replacing avionics to be less important than the cost and hassle of
an installing an externally regulated alternator + over voltage
protection, then go with an internally regulated alternator and skip
the over voltage protection.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
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: | Internal regulation |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Interesting thoughts Kevin...And a nice web site too!
Of course I've already got my internally regulated alt and my avionics
will cost a fortune..rather like yours in fact..:)
I went with one of those kilovolt contators driven by an OV module and
although I can't remember the numbers the break current was monstrously
huge from my recollection.
In short I have a hard time believing it will not break in a OV
event...At least I hope it will..:)
Frank
RV-7A..airframe complete, need to paint cockpit.
Dave,
The first big question is whether you want to have over voltage
protection or not. Some folks who have never heard of any over voltage
cases on cars, figure that an automotive alternator with internal
regulation is reliable enough that they don't worry about an over
voltage. But, there was a message on this list a while back from a guy
who had an automotive alternator on his aircraft that would go into an
over voltage condition as soon as he selected it on. So, over voltages
do happen.
If your avionics are cheap, or you have enough money that you are
prepared to risk them, you could go without over voltage protection.
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: AeroElectric-List Digest: 11 Msgs - 07/11/05 |
--> AeroElectric-List message posted by: "Glaeser, Dennis A" <dennis.glaeser@eds.com>
>Subject: Re: AeroElectric-List Digest: 11 Msgs - 07/11/05
>From: Dave Harmon (vagabondpa15@verizon.net
>Date: Tue Jul 12 - 7:07 AM
>--> AeroElectric-List message posted by: "Dave Harmon"
<vagabondpa15@verizon.net
>Can we go over again why it's not rec. to use internal regulation on
alternators.
>Dave
------------------------------------------------------
Bottom line: inability control the field current (elegantly
enable/disable the Alternator output), and unknown OV protection.
With most IR's, once the field is energized, it 'latches on' and there
is no external way to turn it off - so there is no external way to
disable the alternator in case of OV except by disconnecting the B lead
(which also can cause problems - search the archives for 'load dump').
Many modern automotive IR's have built-in OV protection, and may be just
fine - but it is next to impossible to get technical info on them in
order to make an educated decision. And even if you do, it would be for
that specific (make, model) regulator, not IR's in general. Bob won't
recommend something he can't verify (a reasonable position IMHO).
Dennis Glaeser
RV7A Empennage
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: Internal regulation |
--> AeroElectric-List message posted by: Phil Birkelbach <phil@petrasoft.net>
Excellent reply Kevin,
I went with the internal regulated alternator with a contactor on the
'B' lead (B for Big right :-) ) and the B&C crowbar overvoltage device.
I suspect that some day in the future the regulator inside the
alternator will shed all of it's smoke at which time I'll have it
overhauled and turned into an externally regulated type and buy a
regulator. It'll be a simple change.
The questions about the voltage spike killing the alternator, center
around disconnecting the alternator 'B' lead while the alternator is
producing current. My checklists are set up so that once I turn the
alternator on it stays on until the engine isn't turning anymore. If I
get the overvoltage event and the contactor opens it up then the
assumption is that the regulator is fried anyway.
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB - Finishing Up
http://www.myrv7.com
Kevin Horton wrote:
>--> AeroElectric-List message posted by: Kevin Horton <khorton01@rogers.com>
>
>On 12 Jul 2005, at 10:06, Dave Harmon wrote:
>
>
>
>>--> AeroElectric-List message posted by: "Dave Harmon"
>><vagabondpa15@verizon.net>
>>
>>Can we go over again why it's not rec. to use internal regulation on
>>alternators.
>>Dave
>>
>>
>
>
>Dave,
>
>The first big question is whether you want to have over voltage
>protection or not. Some folks who have never heard of any over
>voltage cases on cars, figure that an automotive alternator with
>internal regulation is reliable enough that they don't worry about an
>over voltage. But, there was a message on this list a while back
>from a guy who had an automotive alternator on his aircraft that
>would go into an over voltage condition as soon as he selected it
>on. So, over voltages do happen.
>
>If your avionics are cheap, or you have enough money that you are
>prepared to risk them, you could go without over voltage protection.
>
>If you want over voltage protection, and you use an externally
>regulated alternator, the over voltage protection device can simply
>cut the power between the voltage regulator and the alternator
>field. This line only has small current in it, so there is no
>problem to chop the power if an over voltage ever occurs.
>
>But, if you have an internally regulated alternator, the wire from
>the voltage regulator to the field is buried inside the alternator -
>you can't get at it. So, the only way to deal with an over voltage
>is to have a contactor in the alternator output that is opened
>automatically if the alternator runs away. This contactor will have
>to open when the alternator is supplying as much current as it can
>possibly do, and there is some question about whether the contactor
>will actually reliably cut the alternator output, or whether it might
>arc internally and weld closed.
>
>There have also been a few unexplained problems with internally
>regulated alternators sold by Van's aircraft if they are installed
>with the over voltage protection sold by B&C Specialties. There have
>been several events where something happened that fried the internal
>regulator, but no one has been able to figure out the cause, so we
>have no fix yet.
>
>If you use an externally regulated alternator, you can use the over
>voltage protection sold by B&C Specialties (and designed by Bob
>Nuckolls). A small number of people have a philosophical problem
>with the way it shorts out the field line to cause the field CB to
>pop open, but no one has been able to demonstrate a real problem with
>the design. It is simple, and it works.
>
>So, my advice: if you want over voltage protection, go with an
>externally regulated alternator. If you judge the cost and hassle of
>replacing avionics to be less important than the cost and hassle of
>an installing an externally regulated alternator + over voltage
>protection, then go with an internally regulated alternator and skip
>the over voltage protection.
>
>
>Kevin Horton RV-8 (finishing kit)
>Ottawa, Canada
>http://www.kilohotel.com/rv8
>
>
>
>
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: | split pin connectors |
--> AeroElectric-List message posted by: <bakerocb@cox.net>
7/12/2005
OC, please pass on to Bob Nuckolls.
A total of seven "split pin connectors" emanating from the autopilot, all
blue in color were found behind the instrument panel of the Beech Sierra,
Each one was first disconnected and then reconnected. No further trouble
shooting took place before an operational test was conducted on the Century
IIB autopilot. The test on the ground was successful, A subsequent airborne
operational test also proved the autopilot to be fully operational.
Thank you again for any time, effort and thought that went into this trouble
shooting. George Philipps
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 |
|
--> AeroElectric-List message posted by: <bakerocb@cox.net>
AeroElectric-List message previously posted by: OC Baker
> ....skip......But I don't know why they would mislead us about the non
> functioning of the IC-A4 on set transmitter button while the headset
> adapter is installed if the button and the radio works OK just like
> Charlie Brame says it does for the IC-A23.
>
> ICOM Tech Support, do you wish to comment?
>
> OC
7/12/2005
I went flying yesterday with a friend and conducted some ground tests with
my ICOM IC-A4 hand held radio. Here is what I observed:
1) With the headset adapter plugged in and a headset connected to the
adapter, the PTT button on the side of the radio activated the transmitter
and normal transmissions could be made with the microphone built into the
radio. Transmissions could be heard by the head set wearer (side tone) and a
separate receiving radio.
2) With the headset adapter plugged in and a headset connected to the
adapter with a standard large size PTT adapter cord (not 3.5mm) in line with
the microphone plug the transmitter could be activated by pushing the PTT
button on the adapter cord. Transmissions could be made with the headset
microphone and could be heard by sidetone in the headset and at a receiving
radio.
Why the IC-A4 manual states or implies that the two operations above cannot
be conducted is beyond me. Both of these modes of operation would be
considered normal and advantageous by any one considering buying or owning a
hand held radio.
ICOM Tech Support, do you wish to comment?
OC
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! --
|