Today's Message Index:
----------------------
1. 06:52 AM - Re: Intermittent Charging (Robert L. Nuckolls, III)
2. 07:23 AM - Re: Re: Primary Power Diagram RV-14 (Robert L. Nuckolls, III)
3. 05:48 PM - Re: Primary Power Diagram RV-14 (Mudfly)
4. 05:57 PM - Re: Intermittent Charging (H. Ivan Haecker)
5. 07:28 PM - Re: Intermittent Charging (user9253)
Message 1
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| Subject: | Re: Intermittent Charging |
At 06:14 PM 3/2/2023, you wrote:
>To those who have been following my sad tale of
>woe, I have good news to report. Today I took my
>alternator to another auto parts store and had
>another test run performed. Again I was told
>that the alternator was performing normally.
Never hurts to have confirmation
>So I =C2 purchased a new regulator (Ford type) and installed
>it. Everything has now returned to normal as the onboard
>volt meter stayed steady at about 14.5 volts no matter
>what the rpm. My conclusion is that despite the original
>regulator seeming to provide expected input to the field
>of the regulator, it wasn't. Perhaps if I had measured
>the current flow as Joe suggested, I could have determined
>that.
The alternator field looks like a resistor
to the regulator. Current flow would have
be proportional to applied voltage and would
have yielded no new information.
It's unfortunate that we didn't arrive at
a definitive conclusion before you got
out wrenches. That test-fixture with a known-
good regulator was crafted with that goal
in mind. The regulators can be had for
a pittance . . .
https://tinyurl.com/2nugnwu8
and the test tool can be re-purposed as a
spare part should it show that the in-service
part is bad.
The appearance of alternator whine was
the signal that chased me down the wrong
rabbit hole. Has that condition resolved?
Also, do you still have your failed
regulator. If you're not nailing carcasses
of bagged predators to the shop wall
I'd like to have it to run on my test
stand and get some measurements.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 2
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| Subject: | Re: Primary Power Diagram RV-14 |
At 02:38 PM 3/2/2023, you wrote:
>
>I have made changes to the Primary Power system design. I switched
>from CBs to fuses as recommended my several. I eliminated one bus
>completely, and moved the Hot Batt Bus firewall fwd . . .
I note that you're planning a rather sophisticated
(and expensive) regulator for the standby alternator.
You also wire it per B*C suggestions to power regulator
from the bus which is not firmly connected to the
b-lead of that same alternator.
In Z101 I suggest a dirt-cheap regulator for standby
service powered from the battery bus. Probability of
needing the stand-by alternator in flight is very
low. It gets pre-flight tested and then 'stowed'.
No o.v. protection necessary . . . the likelihood of
an o.v. event less than 4 hours after a pre-flight
test is low on a system already unlikely to
see service under 'duress'.
Further, powering from the battery bus keeps
the s/b alternator available in every situation.
>One question I have regards the avionics relay. I've read that some
>prefer a normally closed relay in case of switch failure.
Suggest you consider Z-101 philosophy of diode
fed normal power pathways with relays and/or
switches required ONLY for abnormal situations. I.e.
no switches or relays (other than battery
contactor) in distribution pathways.
Yeah, there are many airplanes out there with an
AVIONICS MASTER switch. An idea birthed onto
light aircraft back in the 60's while I was
building my aviation bona fides at Cessna.
I bought into it back then . . . but completely
discounted the concept based on dozens of
troubleshooting, design and certification projects
over the years.
What are the planned instruments for reading
alternator output? Technology of choice calls
for hall-effect sensors as opposed to shunts.
Further, know that alternator b-lead current
is a trouble-shooting adjunct of limited value
on the ground and no value in flight.
You KNOW from having established and verified
design goals what alternator currents are
under various flight conditions. Observing
and pondering those values in flight is a
distraction. BUS VOLTAGE is your primary source
of information on system operation with active
notification of low voltage being the condition
for transition between plan-A and plan-B.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 3
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| Subject: | Re: Primary Power Diagram RV-14 |
[quote="nuckolls.bob(at)aeroelect"]At 02:38 PM 3/2/2023, you wrote:
I have made changes to the Primary Power system design. I switched
from CBs to fuses as recommended my several. I eliminated one bus
completely, and moved the Hot Batt Bus firewall fwd . . .[/quote]
I note that you're planning a rather sophisticated
(and expensive) regulator for the standby alternator.
You also wire it per B*C suggestions to power regulator
from the bus which is not firmly connected to the
b-lead of that same alternator.
In Z101 I suggest a dirt-cheap regulator for standby
service powered from the battery bus. Probability of
needing the stand-by alternator in flight is very
low. It gets pre-flight tested and then 'stowed'.
No o.v. protection necessary . . . the likelihood of
an o.v. event less than 4 hours after a pre-flight
test is low on a system already unlikely to
see service under 'duress'.
Further, powering from the battery bus keeps
the s/b alternator available in every situation.
[quote]One question I have regards the avionics relay. I've read that some
prefer a normally closed relay in case of switch failure. [/quote]
Suggest you consider Z-101 philosophy of diode
fed normal power pathways with relays and/or
switches required ONLY for abnormal situations. I.e.
no switches or relays (other than battery
contactor) in distribution pathways.
Yeah, there are many airplanes out there with an
AVIONICS MASTER switch. An idea birthed onto
light aircraft back in the 60's while I was
building my aviation bona fides at Cessna.
I bought into it back then . . . but completely
discounted the concept based on dozens of
troubleshooting, design and certification projects
over the years.
What are the planned instruments for reading
alternator output? Technology of choice calls
for hall-effect sensors as opposed to shunts.
Further, know that alternator b-lead current
is a trouble-shooting adjunct of limited value
on the ground and no value in flight.
You KNOW from having established and verified
design goals what alternator currents are
under various flight conditions. Observing
and pondering those values in flight is a
distraction. BUS VOLTAGE is your primary source
of information on system operation with active
notification of low voltage being the condition
for transition between plan-A and plan-B.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"[/quote]
Bob,
Thank you for the thorough review and suggestions to my wire plan.
Luckily, I am heading out to work for several days so I have some time
to try and figure it all out and come up with a revision.
Regarding the regulator for the standby alternator. I may have to
keep that in my plan as I have both regulators already mounted,
although not wired yet. I will, however, be changing the
standby field wire to the battery bus. Think I had it that way several revisions
ago and forget why I changed it.
Removing the avionics switch is going to be more difficult. I realize it's
not required and just something else to break. I've been flying a Citation
XLS for 23 years (probably has some of your ideas onboard). It has
an avionics switch that we are required to turn off during starts, even
with the APU running. So for me it's just something I've always had.
With my setup, I would think an avionics relay failure in flight would
hopefully just be a nuisance...unless it caught on fire. It would be more difficult
if it failed on the ground after engine start. That could keep me grounded
a few extra hours.
Now about the shunts. I understand the monitoring of amps during flight
is about as useless as oh, I don't know, an...avionics switch:).
Again, just something I've always had. I see the benefits of the
hall-effect sensors and, if it looks like one will work ok with my garmin
stuff, I will be making that change.
Thanks again for all your help. I'll have a new revision up in about
week.
Shawn
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=510339#510339
Message 4
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| Subject: | Re: Intermittent Charging |
Things did not go so well today. Initially, the system was working normally
with 14.5v on the panel voltmeter at cruise power. 15 minutes into the
flight, the problem reappeared, with the voltmeter once again registering
only battery voltage. And the radio noise came back as well. On my return
trip home, no charging occurred until I got back on the ground, at which
time the voltmeter was back to 14.5 volts. Very discouraging.
Bob, If I ever resolve this problem, I=99ll be happy to send you the
regulator that got replaced. In the meantime, I=99ll be trying anothe
r
regulator for tomorrow=99s flight.
Ivan Haecker
On Sat, Mar 4, 2023 at 8:54 AM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 06:14 PM 3/2/2023, you wrote:
>
> To those who have been following my sad tale of woe, I have good news to
> report. Today I took my alternator to another auto parts store and had
> another test run performed. Again I was told that the alternator was
> performing normally.
>
>
> Never hurts to have confirmation
>
> So I =C3=82 purchased a new regulator (Ford type) and installed
> it. Everything has now returned to normal as the onboard
> volt meter stayed steady at about 14.5 volts no matter
> what the rpm. My conclusion is that despite the original
> regulator seeming to provide expected input to the field
> of the regulator, it wasn't. Perhaps if I had measured
> the current flow as Joe suggested, I could have determined
> that.
>
>
> The alternator field looks like a resistor
> to the regulator. Current flow would have
> be proportional to applied voltage and would
> have yielded no new information.
>
> It's unfortunate that we didn't arrive at
> a definitive conclusion before you got
> out wrenches. That test-fixture with a known-
> good regulator was crafted with that goal
> in mind. The regulators can be had for
> a pittance . . .
>
> https://tinyurl.com/2nugnwu8
>
> and the test tool can be re-purposed as a
> spare part should it show that the in-service
> part is bad.
>
> The appearance of alternator whine was
> the signal that chased me down the wrong
> rabbit hole. Has that condition resolved?
>
> Also, do you still have your failed
> regulator. If you're not nailing carcasses
> of bagged predators to the shop wall
> I'd like to have it to run on my test
> stand and get some measurements.
>
> Bob . . .
>
> Un impeachable logic: George Carlin asked, "If black boxes
> survive crashes, why don't they make the whole airplane
> out of that stuff?"
>
Message 5
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| Subject: | Re: Intermittent Charging |
Intermittent problems are difficult to troubleshoot. Perhaps the alternator
fails at a certain temperature. How about heating the alternator up prior to
having it tested at the auto parts store?
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=510341#510341
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