Chris;
Yeah; what Joe said. Another option in the Velocity is to run some wires through
the keel. Since I chose to separate the wiring to the two sets of
injectors and coils from each other to maintain redundancy all the way from the
dual batteries; I have one set down the right duct and one set through the
keel. You can get by with less than 6” separation, especially for
shorter distances
Another way to cancel induction noise is twisted pairs of
power and ground leads; or as I chose to do is run the power leads inside a
copper pipe (which is inside the right wiring duct), where the pipe is the
ground lead. Probably not something you’d like to try at this point.
Induction noise is one type; the other is spikes generated
in lines by switching inductive loads, like relays and solenoids. These can be
filtered by snubber diodes across the inductive load. I was surprised at the
size of the spike induced by my staging relay (peculiar to the 3-rotor version)
before snubbing.
Of course even with all this, you’ll probably recall
I had a devil of time with corruption of EC2 settings until we finally added
further filtering on the EC2 board. One possible reason is that I have
redundant power leads to the EC2, isolated by diodes at the EC2 since the A/B
controller power is common internally. These diodes will also stop noise
in the EC2 from feeding back to the battery. Never did determine whether
that was an issue as we had solved the problem other ways before considering
it. Capacitors across the diodes could eliminate that issue.
Best of luck,
Al
-----Original
Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf
Of Christopher Barber
Sent: Saturday, June 13, 2009 2:34 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Wire separation?
Since
I have had some apparent wire issues I am individually checking
all
the wires for my ECU, pumps, coils injectors etc.
One
of the things Tracy mentions in the wire instructions is to have
some
wires (ie those running to the injectors and the coils, IIRC) not
be
bundled with other wires. My question is what does this mean
exactly?
I understand you would not actually tie them together in the
same
actual bundle, but, some of the basic path, in my case down the
co-pilot
wire tunnel in a larger canard aircraft, has some of these
wires
in definite immediate proximity of each other. Also, of course,
as
they meet up at the D-sub connections, they run together for a bit.
So,
what is the conventional wisdom on the separation of these "noisy"
wires.
Since I am checking them all, and some of wires need to be
pulled
out to do so properly, it seems to be the ideal time to make sure
this
is done properly and hopefully eliminate one more potential problem.
TIA
All
the best,
Chris
Barber
Houston
Velocity
SE
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