Today's Message Index:
----------------------
1. 01:20 PM - klixon cb (Roger Sherriff)
2. 04:34 PM - Re: klixon cb (Robert L. Nuckolls, III)
3. 05:35 PM - Re: klixon cb (Alec Myers)
4. 06:30 PM - Re: Re: IVO Prop current limiter (Robert L. Nuckolls, III)
5. 07:23 PM - Can Someone PLEASE Provide A Recommendation For A Plunger Switch?!?!? (William Hunter)
6. 07:41 PM - Re: Can Someone PLEASE Provide A Recommendation For A Plunger Switch?!?!? (Charlie England)
7. 07:41 PM - Re: Can Someone PLEASE Provide A Recommendation For A Plunger Switch?!?!? (Charlie England)
8. 07:56 PM - Re: klixon cb (Robert L. Nuckolls, III)
Message 1
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I notice that the top terminal on the klixon circuit breakers is marked "li
ne." Does it matter on which terminal the bus or the LRU go?
Thanks,
Roger.
Message 2
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At 03:19 PM 6/8/2017, you wrote:
>I notice that the top terminal on the klixon circuit breakers is
>marked "line." Does it matter on which terminal the bus or the LRU go?
>
No.
Bob . . .
Message 3
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I just had an issue with recharging a flat aircraft battery by running the e
ngine after a hand start. Not enough residual battery juice to close the mai
n contactor, so no current flowing from the alternator to the battery.
Come to think of it it might be a generator instead of an alternator because
even without a power source for excitation the bus was powering the aircraf
t radio. Still, no current going to the battery with the contactor resolutel
y open.
Is this a really obvious well known phenomenon that I've never really though
t about before?
On Jun 8, 2017, at 16:19, Roger Sherriff <rogsherriff@hotmail.com> wrote:
I notice that the top terminal on the klixon circuit breakers is marked "lin
e." Does it matter on which terminal the bus or the LRU go?
Thanks,
Roger.
Message 4
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| Subject: | Re: IVO Prop current limiter |
At 03:41 PM 6/7/2017, you wrote:
>
>Finally got the plane out to run the engine. I modified the
>circuit, adding the 100 uF capacitor and the 10 Ohm resistor per
>Bob's instruction.
>
>Same behavior as before -- without engine running, the blades would
>change pitch fairly consistently, with an occasional premature
>cut-off at the extremes when trying to reverse the pitch; with the
>engine running, the pitch would change slightly, but the power would
>be cut off rapidly.
>
>I added my multi-meter in the loop to see what kind of current was
>flowing. Without the engine running, cut-off would occur, as
>before, at around 9 Amps.
>
>With the engine running, the meter indicated around 2 to 8 Amps
>before the circuit was shut down, with most readings around 2 to 5
>or so Amps before cut-off. Not sure how reliable the meter readings
>are given the quick circuit shut-down.
Well . . . fooey. This isn't going to be a 'problem'
with your bus voltage. Circuits of this strip are
inherently sensitive to dv/dt (fast rise noise) effects.
Unfortunately, I didn't push this circuit through the
DO160 examination . . . hmmmm . . . I think I was still
at Raytheon/Beech. It's no doubt possible to tranquilize
the little critter with the right test equipment but
that's no longer in my bag of tricks.
Let's go to plan B. In the time since that circuit
was proposed, moving to a digital sensing, timing
and reaction circuit makes a lot of sense. There's
a LOT MORE separate between the bus and the parts
that sift the fine sands of performance.
I'm up to my eyeballs in a couple of programs now
but I'll see if I can sketch out the diagram and
get my super software guy to program a chip
to try.
Watch this space . . .
Bob . . .
Message 5
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| Subject: | Can Someone PLEASE Provide A Recommendation For A |
Plunger Switch?!?!?
Greetings,
I have built a fiberglass air filter box that has an automatic alternate
air
door that I want to monitor with a micro switch and I was hoping someone
could please give me a recommendation for a micro switch to purchase.
The construction of this air filter box is of =BD inch Divinycell foam
board
encapsulated with two layers of fiberglass (see attached photo) and the
alternate air door is a simple fiberglass flapper valve that is held
shut by
the spring action of the fiberglass valve and two magnets.
The design goal is that the flapper valve will shut when the engine is
not
running and then after the engine is started the spring action and the
magnets will hold the flapper valve shut. At times when the air filter
becomes clogged (ice or debris) the engine vacuum will pull on the
flapper
door with enough suction force that the magnets will separate and the
door
will open into the air box and allow unfiltered air from the engine
compartment to flow to the engine. The magnets are encapsulated in the
fiberglass of the door and the air box walls so there is not fear of
them
falling into the engine.
So=85getting back to the switch=85it needs to have the following
attributes:
-Plunger type switch that has a very light spring that forces the switch
plunger to the extended position.
-When the switch is pushed in the contacts need to be open and when the
switch is allowed to extend the contacts need to close so my indicator
light
will illuminate.
-The threaded shaft of the switch should be about =BD inch long.
-Threaded shaft is made of plastic
My goal is to install the switch from the outside so that the switch
body is
on the outside of the box and only the plunger assembly is inserted into
the
sidewall mounting hole just long enough so that the switch will be
pressed
in when the flapper valve is closed. If the threaded shaft is plastic
then
I can use epoxy to glue the switch threads into the sidewall of the air
box
and therefore it would not need a nut on the inside wall of the air box
so
there would be no worry about the nut falling into the engine intake.
Here is a picture of a switch that could work=85I would not use the nuts
and I
would also prefer that the body and the plunger were made of plastic
and I
have no way of knowing how strong the spring is.
If anyone has a suggestion as to the specific switch I should use I
would be
most grateful for the advice!!!
..
Cheers!!!
Bill Hunter
Message 6
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| Subject: | Re: Can Someone PLEASE Provide A Recommendation For |
A Plunger Switch?!?!?
On 6/8/2017 9:22 PM, William Hunter wrote:
>
> Greetings,
>
> I have built a fiberglass air filter box that has an automatic
> alternate air door that I want to monitor with a micro switch and I
> was hoping someone could please give me a recommendation for a micro
> switch to purchase.
>
> The construction of this air filter box is of inch Divinycell foam
> board encapsulated with two layers of fiberglass (see attached photo)
> and the alternate air door is a simple fiberglass flapper valve that
> is held shut by the spring action of the fiberglass valve and two
> magnets.
>
> The design goal is that the flapper valve will shut when the engine is
> not running and then after the engine is started the spring action and
> the magnets will hold the flapper valve shut. At times when the air
> filter becomes clogged (ice or debris) the engine vacuum will pull on
> the flapper door with enough suction force that the magnets will
> separate and the door will open into the air box and allow unfiltered
> air from the engine compartment to flow to the engine. The magnets
> are encapsulated in the fiberglass of the door and the air box walls
> so there is not fear of them falling into the engine.
>
> Sogetting back to the switchit needs to have the following attributes:
>
> -Plunger type switch that has a very light spring that forces the
> switch plunger to the extended position.
>
> -When the switch is pushed in the contacts need to be open and when
> the switch is allowed to extend the contacts need to close so my
> indicator light will illuminate.
>
> -The threaded shaft of the switch should be about inch long.
>
> -Threaded shaft is made of plastic
>
> My goal is to install the switch from the outside so that the switch
> body is on the outside of the box and only the plunger assembly is
> inserted into the sidewall mounting hole just long enough so that the
> switch will be pressed in when the flapper valve is closed. If the
> threaded shaft is plastic then I can use epoxy to glue the switch
> threads into the sidewall of the air box and therefore it would not
> need a nut on the inside wall of the air box so there would be no
> worry about the nut falling into the engine intake.
>
> Here is a picture of a switch that could workI would not use the nuts
> and I would also prefer that the body and the plunger were made of
> plastic and I have no way of knowing how strong the spring is.
>
> 1EN1-6 Honeywell Microswitch
>
> If anyone has a suggestion as to the specific switch I should use I
> would be most grateful for the advice!!!
>
> ..
>
> Cheers!!!
>
> Bill Hunter
>
If you don't write restrictive requirements, you often get more useful
ideas. :-)
https://www.google.com/search?q=magnetic+prox+switch&oq=magnetic+prox+switch&aqs=chrome..69i57j0l5.6126j0j7&sourceid=chrome&ie=UTF-8
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Message 7
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| Subject: | Re: Can Someone PLEASE Provide A Recommendation For |
A Plunger Switch?!?!?
On 6/8/2017 9:42 PM, Charlie England wrote:
> On 6/8/2017 9:22 PM, William Hunter wrote:
>>
>> Greetings,
>>
>> I have built a fiberglass air filter box that has an automatic
>> alternate air door that I want to monitor with a micro switch and I
>> was hoping someone could please give me a recommendation for a micro
>> switch to purchase.
>>
>> The construction of this air filter box is of inch Divinycell foam
>> board encapsulated with two layers of fiberglass (see attached photo)
>> and the alternate air door is a simple fiberglass flapper valve that
>> is held shut by the spring action of the fiberglass valve and two
>> magnets.
>>
>> The design goal is that the flapper valve will shut when the engine
>> is not running and then after the engine is started the spring action
>> and the magnets will hold the flapper valve shut. At times when the
>> air filter becomes clogged (ice or debris) the engine vacuum will
>> pull on the flapper door with enough suction force that the magnets
>> will separate and the door will open into the air box and allow
>> unfiltered air from the engine compartment to flow to the engine.
>> The magnets are encapsulated in the fiberglass of the door and the
>> air box walls so there is not fear of them falling into the engine.
>>
>> Sogetting back to the switchit needs to have the following attributes:
>>
>> -Plunger type switch that has a very light spring that forces the
>> switch plunger to the extended position.
>>
>> -When the switch is pushed in the contacts need to be open and when
>> the switch is allowed to extend the contacts need to close so my
>> indicator light will illuminate.
>>
>> -The threaded shaft of the switch should be about inch long.
>>
>> -Threaded shaft is made of plastic
>>
>> My goal is to install the switch from the outside so that the switch
>> body is on the outside of the box and only the plunger assembly is
>> inserted into the sidewall mounting hole just long enough so that the
>> switch will be pressed in when the flapper valve is closed. If the
>> threaded shaft is plastic then I can use epoxy to glue the switch
>> threads into the sidewall of the air box and therefore it would not
>> need a nut on the inside wall of the air box so there would be no
>> worry about the nut falling into the engine intake.
>>
>> Here is a picture of a switch that could workI would not use the
>> nuts and I would also prefer that the body and the plunger were made
>> of plastic and I have no way of knowing how strong the spring is.
>>
>> 1EN1-6 Honeywell Microswitch
>>
>> If anyone has a suggestion as to the specific switch I should use I
>> would be most grateful for the advice!!!
>>
>> ..
>>
>> Cheers!!!
>>
>> Bill Hunter
>>
> If you don't write restrictive requirements, you often get more useful
> ideas. :-)
>
> https://www.google.com/search?q=magnetic+prox+switch&oq=magnetic+prox+switch&aqs=chrome..69i57j0l5.6126j0j7&sourceid=chrome&ie=UTF-8
or more specifically,
https://www.google.com/search?q=magnetic+prox+switch&oq=magnetic+prox+switch&aqs=chrome..69i57j0l5.6126j0j7&sourceid=chrome&ie=UTF-8#q=surface+mount+window+contact
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Message 8
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At 07:33 PM 6/8/2017, you wrote:
>I just had an issue with recharging a flat aircraft battery by
>running the engine after a hand start. Not enough residual battery
>juice to close the main contactor, so no current flowing from the
>alternator to the battery.
>
>Come to think of it it might be a generator instead of an alternator
>because even without a power source for excitation the bus was
>powering the aircraft radio. Still, no current going to the battery
>with the contactor resolutely open.
>
>Is this a really obvious well known phenomenon that I've never
>really thought about before?
Waaayyy back in the dark ages . . . but after Lucky Lindy,
only generators were considered to be 'self exciting' but
then only if the field was 'flashed' so as to possess some
residual magnetism. Alternators too had some non-zero
retentivity but generally too low to bring an alternator
on line at ordinary speeds.
There WERE notable exceptions. Alternators on the Bonanzas
and Barons were expected to self excite at cruise rpms . . .
and most did . . . but that's an interesting story for another
time.
Today's alternators, PARTICULARLY those that run nearly 10k
rpm on the front of a Lycoming will come on line self excited
if lightly loaded . . . and will run well. So your observation
may not be a strange as you would think.
Having said that, it's generally a poor idea to recharge
a flat battery with the ship's alternator . . . use
jumper cables to an automobile for a few minutes to stir
up the battery's chemistry and avoid unpredictable
perturbations of bus voltage during early phase of
recharge . . . and know this is not very good for
the battery's service life. Putting a regulated, 10A
charger on it for an hour or so is much preferred.
Bob . . .
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