Today's Message Index:
----------------------
1. 06:53 AM - Apparent grounding problems (Sam Hoskins)
2. 07:07 AM - Re: db connector hold-down screws (Sam Hoskins)
3. 07:55 AM - Re: Apparent grounding problems (Carlos Trigo)
4. 08:34 AM - Re: Apparent grounding problems (Charlie England)
5. 10:55 AM - Re: power wires to strobe power supply (MHerder)
6. 01:05 PM - Diode type, size (Dan Billingsley)
7. 01:26 PM - Re: Re: power wires to strobe power supply (Robert L. Nuckolls, III)
8. 02:15 PM - Bob's take? (Dan Billingsley)
9. 04:56 PM - Re: Apparent grounding problems (Sam Hoskins)
10. 05:36 PM - Re: Apparent grounding problems (Charlie England)
Message 1
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| Subject: | Apparent grounding problems |
I am experiencing a digital "flicker" in a couple of my electronic engine
indicators. I am using a Dynon D180 in my all composite Quickie Q-200.
The problem is most apparent in the oil temp. It rapidly bounces from 190,
to 235, to 200, etc, many times a second. A couple of the other instruments
do the same, but the oil temp is the worst.
I contacted Dynon and they said most likely it is a "bad ground". I am
attaching a crude sketch of my instrumentation ground system. (I don't have
the backside of the forest of tabs grounding block mounted directly to the
firewall, because is just so very hard to access, so I have an 8AWG wire
connecting the two.)
The Dynon oil temp sensor is a single wire unit, with the ground path
completed through the engine. Dynon suggested I try a GRT two wire sensor.
I may do this, but I have to pull the engine to access the accessory case,
and besides, I want to get at the root cause.
Any suggestions?
Thanks.
Sam Hoskins
Murphysboro, IL
www.samhoskins.blogspot.com
Message 2
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| Subject: | Re: db connector hold-down screws |
You can purchase ready made connector hold down screws from Stein
Ai<http://www.steinair.com/>r,
in Minnesota. They are about 1.5" long and have a knurled post. I bought
several and will be switching them out every time I undo a connector.
They may not be in the on-line offering. Just give them a call, they are
very helpful.
Sam
On Tue, Sep 28, 2010 at 6:18 AM, <bakerocb@cox.net> wrote:
>
> 9/28/2010
>
> Hello J. Davis, You wrote: ".....how to fabricate hold-down screws for db
> connectors
> installed with no shells, but now can't locate it."
>
> See my posting of 5/29/2010 copied below.
>
> 'OC' Baker Says: "The best investment we can make is the time and effort to
> gather and understand knowledge."
>
> PS: Phillips drive machine screws are an abomination. Every builder who has
> converted to the Torx (6 lobe) drive screws has been delighted with the
> results.
>
> =======================================================
>
> Time: 11:03:43 AM PST US
> From: "j. davis" <jd@lawsonimaging.ca>
> Subject: AeroElectric-List: db connector hold-down screws
>
> Greetings...
>
> I remember seeing an article on how to fabricate hold-down screws for db
> connectors
> installed with no shells, but now can't locate it. I know it's not exactly
> rocket
> science,
> but would like to re-read the article. I'm pretty sure it was aeroelectric
> list
> related...
>
> Thanks!
>
> Regards, J.
> ========================================================
>
> Match: #2Message: #49535From: <bakerocb(at)cox.net>Subject: D-subminiature
> ConnectorsDate: May 29, 2010
>
> 5/29/2010
>
> Hello Fellow Builders, Here is what we are writing about:
>
> http://en.wikipedia.org/wiki/D-subminiature
>
> Bob Nuckolls writes: "It's a fact that the majority of d-sub connectors
> come
> with short, slotted-head 4-40 jack screws that are EXCEEDINGLY
> difficult to work with in confined spaces traversed by wire
> bundles." ..and ... "the inconvenience of stock, slot-head jack-screws."
>
> {RESPONSE} He offers a screw handling solution here:
>
> http://tinyurl.com/34nrdd5
>
> I'd like to offer another solution -- use #4-40 machine screws with hex
> socket (Allen wrench) drive heads. The hex socket drive head allows one to
> manuever the small screws in a manner vastly superior to a straight slot or
> phillips drive head screw.
>
> See here for a source of such screws:
>
> http://www.microfasteners.com/catalog/products/SSC.cfm
>
> Here is just one source of tools for handling these screws:
>
> http://www.bondhus.com/
>
> Conventional Allen wrenches work fine for most handling of these screws,
> but
> these Prohold tools will give even more control if needed:
>
> http://www.bondhus.com/features/prohold/body-0.htm
>
> 'OC' Says: "The best investment we can make is the effort to gather and
> understand knowledge."
>
> PS: An aerospace vehicle with hex socket or Torx / six lobe / star drive
> fasteners is much easier to work on than a vehicle with straight slot or
> Phillips drive fasteners. See here for some handy tool kits to work with
> the
> hex socket or Torx / six lobe / star drive fasteners:
>
> http://www.chapmanmfg.com/
>
> ======================================================
>
>
> DO NOT ARCHIVE
>
>
Message 3
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| Subject: | Apparent grounding problems |
Sam
When they say "bad ground", they are not referring to a bad ground design
but to a deficient ground connection.
You should look for loose or corroded ground connections.
Carlos
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Sam
Hoskins
Sent: domingo, 3 de Outubro de 2010 14:49
Subject: AeroElectric-List: Apparent grounding problems
I am experiencing a digital "flicker" in a couple of my electronic engine
indicators. I am using a Dynon D180 in my all composite Quickie Q-200.
The problem is most apparent in the oil temp. It rapidly bounces from 190,
to 235, to 200, etc, many times a second. A couple of the other instruments
do the same, but the oil temp is the worst.
I contacted Dynon and they said most likely it is a "bad ground". I am
attaching a crude sketch of my instrumentation ground system. (I don't have
the backside of the forest of tabs grounding block mounted directly to the
firewall, because is just so very hard to access, so I have an 8AWG wire
connecting the two.)
The Dynon oil temp sensor is a single wire unit, with the ground path
completed through the engine. Dynon suggested I try a GRT two wire sensor.
I may do this, but I have to pull the engine to access the accessory case,
and besides, I want to get at the root cause.
Any suggestions?
Thanks.
Sam Hoskins
Murphysboro, IL
www.samhoskins.blogspot.com
Message 4
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| Subject: | Re: Apparent grounding problems |
On 10/3/2010 8:49 AM, Sam Hoskins wrote:
> I am experiencing a digital "flicker" in a couple of my electronic
> engine indicators. I am using a Dynon D180 in my all composite
> Quickie Q-200.
>
> The problem is most apparent in the oil temp. It rapidly bounces from
> 190, to 235, to 200, etc, many times a second. A couple of the other
> instruments do the same, but the oil temp is the worst.
>
> I contacted Dynon and they said most likely it is a "bad ground". I
> am attaching a crude sketch of my instrumentation ground system. (I
> don't have the backside of the forest of tabs grounding block mounted
> directly to the firewall, because is just so very hard to access, so I
> have an 8AWG wire connecting the two.)
>
> The Dynon oil temp sensor is a single wire unit, with the ground path
> completed through the engine. Dynon suggested I try a GRT two wire
> sensor. I may do this, but I have to pull the engine to access
> the accessory case, and besides, I want to get at the root cause.
>
> Any suggestions?
>
> Thanks.
>
> Sam Hoskins
> Murphysboro, IL
> www.samhoskins.blogspot.com <http://www.samhoskins.blogspot.com>
>
>
Hi Sam,
Some have had problems with sensors being insulated from the engine
itself by the thread sealant. Hard to believe, but that's what some have
reported.
How is the engine ground tied to your 'forest of tabs' common ground
point? (Trying to use the steel motor mount as a conductor can cause
problems.) What are you using for your firewall feed-through, a good
conductor like brass or copper, or a steel bolt (not so good)?
Then the obvious: check existing wiring for good, solid connections.
Take close looks at all your sub-D connectors, especially if you used
crimp type pins that can be added/removed. It's not unusual for one to
partly back out of a housing, causing an intermittent connection.
Charlie
Message 5
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| Subject: | Re: power wires to strobe power supply |
I FOUND IT. Strobe power supply wires to close and parallel with com and radio
wires. What type of interference is that considered? And does shielding help
it?
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=314505#314505
Message 6
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| Subject: | Diode type, size |
Greetings,
At the risk of being a possible echo, I will ask the question anyway...
(searched the book and the archives)
Is there a common type & or size diode I should use on my Batt contactor? The
theory makes perfect sence to protect the master switch...I'm ready to go get
one...so what would I ask for?
Thanks,
Dan
Message 7
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| Subject: | Re: power wires to strobe power supply |
At 12:50 PM 10/3/2010, you wrote:
<michaelherder@beckgroup.com>
I FOUND IT. Strobe power supply wires to close and parallel with com
and radio wires. What type of interference is that considered?
Electro-magnetic coupling. See narrative on my first
mini-van purchase at OSH way back when. Pages 16-10 to
16-12 of the 'Connection.
And does shielding help it?
No.
This coupling mode can be broken by any one
of three ways:
Preservation of the "parallel conductors
configuration for inbound-outbound electrons
in either (1) the antagonist's power lines
or (2) the victim's signal lines or (3) increased
spacing between the two pathways as described
in the narrative on my mini-van and demonstrated
again by your experience cited above.
Good detective work!
Bob . . .
Message 8
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Bob, if you get a chance, take a look at the Rotax list as there is an
interestiing difference of opinion concerning Amps and wire sizes. I would like
your take on it.
Dan
Message 9
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| Subject: | Re: Apparent grounding problems |
Charlie, were you able to get the pdf attachment in the original e-mail? It
shows how the grounds pass through the firewall.
I'm not sure, but I believe I used a goo-type thread sealant on the temp
sensor, not teflon tape. It's hard to check, because the accessory case is
buried in the firewall.
Sam
On Sun, Oct 3, 2010 at 10:28 AM, Charlie England <ceengland@bellsouth.net>wrote:
> ceengland@bellsouth.net>
>
>
> On 10/3/2010 8:49 AM, Sam Hoskins wrote:
>
>> I am experiencing a digital "flicker" in a couple of my electronic engine
>> indicators. I am using a Dynon D180 in my all composite Quickie Q-200.
>>
>> The problem is most apparent in the oil temp. It rapidly bounces from
>> 190, to 235, to 200, etc, many times a second. A couple of the other
>> instruments do the same, but the oil temp is the worst.
>>
>> I contacted Dynon and they said most likely it is a "bad ground". I am
>> attaching a crude sketch of my instrumentation ground system. (I don't have
>> the backside of the forest of tabs grounding block mounted directly to the
>> firewall, because is just so very hard to access, so I have an 8AWG wire
>> connecting the two.)
>>
>> The Dynon oil temp sensor is a single wire unit, with the ground path
>> completed through the engine. Dynon suggested I try a GRT two wire sensor.
>> I may do this, but I have to pull the engine to access the accessory case,
>> and besides, I want to get at the root cause.
>>
>> Any suggestions?
>>
>> Thanks.
>>
>> Sam Hoskins
>> Murphysboro, IL
>> www.samhoskins.blogspot.com <http://www.samhoskins.blogspot.com>
>>
>>
>> Hi Sam,
>
> Some have had problems with sensors being insulated from the engine itself
> by the thread sealant. Hard to believe, but that's what some have reported.
>
> How is the engine ground tied to your 'forest of tabs' common ground point?
> (Trying to use the steel motor mount as a conductor can cause problems.)
> What are you using for your firewall feed-through, a good conductor like
> brass or copper, or a steel bolt (not so good)?
>
> Then the obvious: check existing wiring for good, solid connections. Take
> close looks at all your sub-D connectors, especially if you used crimp type
> pins that can be added/removed. It's not unusual for one to partly back out
> of a housing, causing an intermittent connection.
>
> Charlie
>
>
Message 10
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| Subject: | Re: Apparent grounding problems |
Oops. I love my Thunderbird email client, but one thing I *don't* care
for is that it puts any attachment list at the bottom of the email,
instead of on the upper right, like most programs.
Looks like you can cross off the firewall pass-through issue.
I'd 'exercise' the Fast-on connectors, especially on the engine side, &
pull test to be sure there aren't loose crimps. If things get more
stable after that, it would be a hint, anyway.
And don't forget the sub-D pins in their housing; that one has actually
happened to me on the back of a comm radio.
Charlie
On 10/3/2010 6:52 PM, Sam Hoskins wrote:
> Charlie, were you able to get the pdf attachment in
> the original e-mail? It shows how the grounds pass through the firewall.
>
> I'm not sure, but I believe I used a goo-type thread sealant on the
> temp sensor, not teflon tape. It's hard to check, because the
> accessory case is buried in the firewall.
>
> Sam
>
>
> On Sun, Oct 3, 2010 at 10:28 AM, Charlie England
> <ceengland@bellsouth.net <mailto:ceengland@bellsouth.net>> wrote:
>
> <ceengland@bellsouth.net <mailto:ceengland@bellsouth.net>>
>
>
> On 10/3/2010 8:49 AM, Sam Hoskins wrote:
>
> I am experiencing a digital "flicker" in a couple of my
> electronic engine indicators. I am using a Dynon D180 in my
> all composite Quickie Q-200.
>
> The problem is most apparent in the oil temp. It rapidly
> bounces from 190, to 235, to 200, etc, many times a second. A
> couple of the other instruments do the same, but the oil temp
> is the worst.
>
> I contacted Dynon and they said most likely it is a "bad
> ground". I am attaching a crude sketch of my instrumentation
> ground system. (I don't have the backside of the forest of
> tabs grounding block mounted directly to the firewall, because
> is just so very hard to access, so I have an 8AWG wire
> connecting the two.)
>
> The Dynon oil temp sensor is a single wire unit, with the
> ground path completed through the engine. Dynon suggested I
> try a GRT two wire sensor. I may do this, but I have to pull
> the engine to access the accessory case, and besides, I want
> to get at the root cause.
>
> Any suggestions?
>
> Thanks.
>
> Sam Hoskins
> Murphysboro, IL
> www.samhoskins.blogspot.com
> <http://www.samhoskins.blogspot.com>
> <http://www.samhoskins.blogspot.com>
>
>
> Hi Sam,
>
> Some have had problems with sensors being insulated from the
> engine itself by the thread sealant. Hard to believe, but that's
> what some have reported.
>
> How is the engine ground tied to your 'forest of tabs' common
> ground point? (Trying to use the steel motor mount as a conductor
> can cause problems.) What are you using for your firewall
> feed-through, a good conductor like brass or copper, or a steel
> bolt (not so good)?
>
> Then the obvious: check existing wiring for good, solid
> connections. Take close looks at all your sub-D connectors,
> especially if you used crimp type pins that can be added/removed.
> It's not unusual for one to partly back out of a housing, causing
> an intermittent connection.
>
> Charlie
>
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