Today's Message Index:
----------------------
1. 01:13 AM - Re: Noise filter (Ron Quillin)
2. 03:40 AM - Re: Noise filter (Robert Feldtman)
3. 10:01 AM - Multi functions for a hat switch (Alex Balic)
4. 10:59 PM - Re: Thermocouple wire connections (captbly)
5. 11:24 PM - Re: Multi functions for a hat switch (B Tomm)
Message 1
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| Subject: | Re: Noise filter |
At 22:00 8/2/2007, you wrote:
>A cohort is having problems with a Century autopilot induced audio
>noise into his headphones.
What model CFS system is it?
Ron Q.
Message 2
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| Subject: | Re: Noise filter |
You might try wrappig about eight wraps of the power, and control cables
through a ferrite bead (palomar engineers)- I assume you are using twisted
pair or coax shielded wire?
bobf
W5RF
On 8/3/07, Doug Windhorn <N1DeltaWhiskey@comcast.net> wrote:
>
> N1DeltaWhiskey@comcast.net>
>
> Bob, et al,
>
> A cohort is having problems with a Century autopilot induced audio noise
> into his headphones. From any testing we have done, this appears to be
> motor noise (based on spool-up/spool-down noise) transmitted into the
> power
> lines. The Century information indicates that it can produce noise in
> some
> avionics at the 5 kHz level. If it is not power line noise, then it might
> be EMF radiation being picked up by the radio or phone circuits.
>
> I have found some information regardng design of a "twin-T band-stop"
> filter
> that could probably be used to filter the offending frequency out of the
> offenders power line.
>
> Assume others have probably had this type of problem an wondering how it
> was
> solved.
>
> On the dumb question front, the above circuit references a source and
> load.
> I would normally think of the power supply as the source and the autopilot
> the load. But, given the noise is from the autopilot, would it not be the
> source and the rest of the circuit the load?
>
> Any insight appreciated.
>
> Doug Windhorn
>
>
Message 3
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| Subject: | Multi functions for a hat switch |
Does anyone know of a schematic that I can use to control the functions of a
hat switch using a 3 position switch to create 3 separate functions for the
hat? The 3 position switch will create the logic for the 3 functions, but I
need some sort of relay board or transistor array to change the routing of
the hat outputs and I have been penciling around and am getting a bit
stumped as to the best way to do it- any help would be appreciated- there
are 4 normally open switches on the hat and the 3 position switch uses 3
wires.......
Message 4
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| Subject: | Re: Thermocouple wire connections |
Dean,
The material of the connectors do not really matter as long as its the same material
on both sides. Since there is no temperature difference on either side
(as long as you dont have one connector laying against the engine), any effect
is canceled out.
Now if you were making a connection at the firewall you would have a temperature
difference on one side of the connector that would enduce a little bit of an
error, all though this too probably isnt much.
The bigger issue is the mating of the two connectors. I would go with the Vision
connectors (Thomas & Betts) first, when these fastons mate together they are
very difficult to pull apart (a good thing) With the thermocouple wire the
insulation crimp is negligible.
best regards
dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=127430#127430
Message 5
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| Subject: | Multi functions for a hat switch |
Alex,
Since no one has replied I will try to answer your question. You need a
quad pole, triple throw switch. One of the various electronic warehouses
may have it such as McMaster-Carr , Electrosonic, etc may have it. Possibly
radio Shack too.
What are you trying to accomplish?
Bevan
RV7A wiring
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alex
Balic
Sent: Friday, August 03, 2007 10:01 AM
Subject: AeroElectric-List: Multi functions for a hat switch
--> <velocity_pilot@verizon.net>
Does anyone know of a schematic that I can use to control the functions of a
hat switch using a 3 position switch to create 3 separate functions for the
hat? The 3 position switch will create the logic for the 3 functions, but I
need some sort of relay board or transistor array to change the routing of
the hat outputs and I have been penciling around and am getting a bit
stumped as to the best way to do it- any help would be appreciated- there
are 4 normally open switches on the hat and the 3 position switch uses 3
wires.......
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